AP 211 Review Exam 1

  • AP
Reviewed by Editorial Team
The ProProfs editorial team is comprised of experienced subject matter experts. They've collectively created over 10,000 quizzes and lessons, serving over 100 million users. Our team includes in-house content moderators and subject matter experts, as well as a global network of rigorously trained contributors. All adhere to our comprehensive editorial guidelines, ensuring the delivery of high-quality content.
Learn about Our Editorial Process
| By Charlies7711
C
Charlies7711
Community Contributor
Quizzes Created: 1 | Total Attempts: 175
| Attempts: 175 | Questions: 155 | Updated: Mar 21, 2025
Please wait...
Question 1 / 155
0 %
0/100
Score 0/100
1. The shape of the lense is controlled by the

Explanation

The ciliary muscles control the shape of the lens in the eye. These muscles are located in the ciliary body, which is part of the iris. When the ciliary muscles contract, they cause the lens to become thicker, allowing the eye to focus on near objects. When the ciliary muscles relax, the lens becomes thinner, allowing the eye to focus on distant objects. Therefore, the ciliary muscles play a crucial role in adjusting the shape of the lens to ensure clear vision at different distances.

Submit
Please wait...
About This Quiz
Sensory Organs Quizzes & Trivia

AP 211 Review Exam 1 assesses understanding of human sensory systems, including gustatory and olfactory receptors, and lacrimal gland functions. It aims to prepare learners for advanced placement exams by testing specific physiological knowledge.

2.
We’ll put your name on your report, certificate, and leaderboard.
2. In the human eye most refraction occurs when light passes through the

Explanation

The cornea is the clear, dome-shaped front surface of the eye that is responsible for most of the eye's focusing power. When light enters the eye, it first passes through the cornea, which bends or refracts the light rays. This refraction helps to focus the light onto the retina at the back of the eye, allowing us to see clearly. The cornea accounts for approximately two-thirds of the eye's total optical power and plays a crucial role in the eye's overall ability to focus light.

Submit
3. The ciliary muscle contracts to

Explanation

The ciliary muscle contracts to adjust the shape of the lens for near vision. When the ciliary muscle contracts, it causes the lens to become more rounded, which increases its refractive power. This allows the eye to focus on objects that are close to the viewer.

Submit
4. There are three different types of cones, each one sensitive to different light energies. These cones are designated

Explanation

The correct answer is red, green, blue. This is because the three different types of cones in the human eye are sensitive to different light energies. These cones are commonly referred to as red, green, and blue cones. They allow us to perceive a wide range of colors by combining the signals from these three types of cones.

Submit
5. An area of the retina that contains only cones and is the site of sharpest vision is the

Explanation

The fovea is the area of the retina that contains only cones, which are responsible for color vision and visual acuity. It is the site of sharpest vision because it has a high concentration of cones and a thinner layer of ganglion cells, allowing for more precise and detailed visual information to be transmitted to the brain. The fovea is responsible for our ability to see fine details and is especially important for activities such as reading and recognizing faces.

Submit
6. If your vision is 20/15 this means that you can

Explanation

If your vision is 20/15, it means that you can see objects at 20 feet away that individuals with normal eyesight can see at 15 feet. This indicates that you have better than average visual acuity, as you can see objects at a greater distance compared to those with normal eyesight. Specifically, you can read 20 point type (which refers to a specific size of text) at a distance of 15 feet.

Submit
7. Which of these is true about the atrial reflex?

Explanation

The atrial reflex is true about being triggered by increasing venous return, also called the Bainbridge reflex, depending on sympathetic innervation, and being triggered by atrial mechanoreceptors.

Submit
8. An elongae outer segment containing membranous discs and a narrow connecting stalk that attaches the outer segment to the inner segment describes

Explanation

The given description of an elongated outer segment containing membranous discs and a narrow connecting stalk that attaches the outer segment to the inner segment is characteristic of a photoreceptor. Photoreceptors are specialized cells in the retina of the eye that are responsible for detecting light and converting it into electrical signals that can be processed by the brain. The outer segment of a photoreceptor contains the photopigment molecules that capture light, while the inner segment contains the cell's nucleus and other organelles necessary for cellular function. The connecting stalk allows for communication between the outer and inner segments.

Submit
9. When all three cone populations are stimulated equally, we perceive

Explanation

When all three cone populations are stimulated equally, the perception of white color is created. This is because white light contains a combination of all colors in the visible spectrum. When the cones that are responsible for detecting different colors (blue, green, and red) are all stimulated equally, the brain interprets this as white light.

Submit
10. Visual pigments are derivatives of the compound

Explanation

Rhodopsin is the correct answer because visual pigments are indeed derivatives of this compound. Rhodopsin is a pigment found in the rods of the retina, which are responsible for vision in low light conditions. It consists of a protein called opsin and a light-sensitive molecule called retinal. When light hits rhodopsin, retinal undergoes a structural change, triggering a series of biochemical reactions that ultimately result in the generation of electrical signals that are sent to the brain for visual processing. Thus, rhodopsin plays a crucial role in the initial steps of vision.

Submit
11. Gravity and linear acceleration are sensed in the

Explanation

The saccule and utricle are part of the vestibular system, which is responsible for sensing gravity and linear acceleration. These structures contain specialized sensory cells that detect changes in head position and movement. When the head moves or changes position, the movement of fluid within the saccule and utricle stimulates hair cells, which then send signals to the brain to help maintain balance and spatial orientation. The organ of Corti is responsible for hearing, while the semicircular canals detect rotational movement. Therefore, the correct answer is saccule and utricle.

Submit
12. Which of the following would you expect to see in increased numbers in a peripheral blood sample after donating a unit of blood?

Explanation

After donating a unit of blood, it is expected to see increased numbers of reticulocytes in a peripheral blood sample. Reticulocytes are immature red blood cells that are released into the bloodstream from the bone marrow. They eventually mature into erythrocytes (red blood cells). After blood donation, the body needs to replenish the lost blood, so the bone marrow increases its production of reticulocytes to ensure an adequate supply of red blood cells. Therefore, an increased number of reticulocytes in the peripheral blood sample indicates the body's response to blood donation.

Submit
13. The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the

Explanation

The foramen ovale is a small opening in the interatrial septum of the fetal heart that allows blood to bypass the non-functional fetal lungs. This structure allows oxygenated blood from the placenta to flow from the right atrium to the left atrium, where it can be pumped out to the rest of the body. After birth, when the lungs become functional, the foramen ovale closes and eventually forms the fossa ovalis, a depression in the interatrial septum. This ensures that blood now flows through the lungs for oxygenation.

Submit
14. Which of the following is not one of the six primary taste sensations?

Explanation

Peppery is not one of the six primary taste sensations because it is not recognized as a distinct taste by the human tongue. The six primary taste sensations are sweet, salty, sour, bitter, umami, and metallic. Peppery taste is often associated with the sensation of spiciness, which is caused by compounds like capsaicin found in chili peppers. However, spiciness is not considered a primary taste sensation but rather a sensation of heat or pain.

Submit
15. The taste sensation that is triggered by the amino group glutamate is known as

Explanation

Umami is the taste sensation triggered by the amino group glutamate. It is often described as a savory or meaty taste, and is commonly found in foods such as mushrooms, tomatoes, and soy sauce. Umami adds depth and richness to dishes and is considered one of the five basic tastes, along with sweet, salty, sour, and bitter.

Submit
16. The most abundant proteins in blood plasma are

Explanation

Albumins are the most abundant proteins in blood plasma. They are synthesized in the liver and play a crucial role in maintaining the osmotic pressure of blood, which helps regulate the distribution of fluids between the blood and tissues. Albumins also transport various substances such as hormones, fatty acids, and drugs throughout the body. Additionally, they contribute to the maintenance of pH balance and act as antioxidants. Due to their abundance and diverse functions, albumins are essential for overall physiological homeostasis.

Submit
17. A ray of light entering the eye will encounter these structures in which order?

Explanation

The correct order in which a ray of light entering the eye will encounter these structures is conjunctiva-cornea-aqueous humor-lens-vitreous body-retina-choroid. The conjunctiva is the thin, transparent layer that covers the front of the eye. The cornea is the clear, dome-shaped structure that covers the front of the eye. The aqueous humor is the clear fluid that fills the space between the cornea and the lens. The lens is a transparent structure that helps focus light onto the retina. The vitreous body is a gel-like substance that fills the space behind the lens and helps maintain the shape of the eye. The retina is the light-sensitive tissue that lines the back of the eye. The choroid is the layer of blood vessels that nourishes the retina.

Submit
18. The external ear ends at the

Explanation

The external ear refers to the part of the ear that is visible on the outside of the head. It consists of the pinna, which is the fleshy outer part of the ear, and the ear canal. The external ear ends at the tympanic membrane, also known as the eardrum. The tympanic membrane separates the external ear from the middle ear and plays a crucial role in transmitting sound vibrations to the middle ear.

Submit
19. A hematocrit provides information on

Explanation

A hematocrit provides information on formed elements abundance. Hematocrit is a measure of the percentage of red blood cells in the total volume of blood. It indicates the proportion of formed elements (red blood cells, white blood cells, and platelets) in the blood. By measuring the hematocrit level, healthcare professionals can assess the abundance of these formed elements and determine if there are any abnormalities or imbalances in the blood composition.

Submit
20. The auditory ossicles connect the

Explanation

The auditory ossicles, which include the malleus, incus, and stapes, are a chain of small bones in the middle ear. Their primary function is to transmit sound vibrations from the tympanic membrane (eardrum) to the inner ear. The malleus is attached to the tympanic membrane, while the stapes is connected to the oval window. Therefore, the correct answer is that the auditory ossicles connect the tympanic membrane to the oval window.

Submit
21. The vibrations recieved by the tympanic membrane are transferred to the oval window by the

Explanation

The vibrations received by the tympanic membrane are transferred to the oval window by the auditory ossicles. The auditory ossicles consist of three small bones in the middle ear: the malleus (hammer), incus (anvil), and stapes (stirrup). These bones amplify and transmit sound vibrations from the eardrum to the oval window, which is a membrane that separates the middle ear from the inner ear. This transfer of vibrations is crucial for the process of hearing.

Submit
22. The middle ear communicates with the nasopharynx through the

Explanation

The middle ear communicates with the nasopharynx through the auditory tube. This tube, also known as the Eustachian tube, connects the middle ear to the back of the throat. It plays a crucial role in equalizing the pressure between the middle ear and the outside environment, allowing the eardrum to vibrate properly. This helps to prevent discomfort and potential damage to the ear.

Submit
23. The senses of equilibrium and hearing are provided by receptors of the

Explanation

The correct answer is inner ear because the inner ear is responsible for both the senses of equilibrium and hearing. It contains the cochlea, which is responsible for hearing, and the vestibular system, which is responsible for balance and spatial orientation. The inner ear is filled with fluid called endolymph, which helps transmit sound vibrations and maintain balance. The other options mentioned, such as perilymph, membranous endolymph, bony labyrinth, and organ of Schlemm, are not directly involved in providing the senses of equilibrium and hearing.

Submit
24. Excess fluid in the                  causes cardiac tamponade

Explanation

Excess fluid in the pericardial cavity can cause cardiac tamponade. The pericardial cavity is the space between the visceral and parietal layers of the pericardium, which are the two layers that surround the heart. When there is an accumulation of fluid in this cavity, it can put pressure on the heart and prevent it from filling and pumping blood effectively, leading to cardiac tamponade. This condition is a medical emergency and requires immediate treatment to relieve the pressure and restore normal heart function.

Submit
25. The structure that overlies the organ of Corti (spiral organ) is the

Explanation

The tectorial membrane is a structure that overlies the organ of Corti, which is also known as the spiral organ. It is a gelatinous structure that extends from the bony shelf above the hair cells to the outer hair cells. The tectorial membrane plays a crucial role in the process of hearing by bending the stereocilia of the hair cells when sound vibrations are transmitted through the cochlea. This bending generates electrical signals that are then sent to the brain for interpretation.

Submit
26. The structure that supports the spiral organ (of Corti) is the

Explanation

The basilar membrane is the correct answer because it is the structure that supports the spiral organ, also known as the organ of Corti, which is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. The basilar membrane is a thin, flexible membrane that runs along the length of the cochlea and contains specialized hair cells that are essential for hearing. These hair cells are stimulated by the movement of the basilar membrane in response to sound vibrations, allowing us to perceive and interpret different frequencies and pitches.

Submit
27. When an external force bends the stereocilia of the inner ear hair cells

Explanation

When an external force bends the stereocilia of the inner ear hair cells, there is a change in the transmembrane potential of the hair cells. This change in potential is a result of the mechanical stimulation caused by the bending of the stereocilia. The transmembrane potential is an electrical charge difference across the cell membrane, and any alteration in this potential can affect the normal functioning of the hair cells. This change in potential can lead to various physiological responses, including dizziness, as the hair cells are responsible for detecting and transmitting sound and balance information to the brain.

Submit
28. A  person with Type A blood has

Explanation

A person with Type A blood has antigen A on their red blood cells (RBCs), which means that their RBCs have a specific marker that distinguishes them as Type A. Additionally, they have anti-B agglutinins in their plasma, which are antibodies that can cause clumping or agglutination of Type B blood cells. This means that if Type B blood is introduced into the bloodstream of a person with Type A blood, their antibodies will react with the Type B blood cells. Therefore, the correct answer is A and B only.

Submit
29. The enzyme that can digest fibrin and dissolve a clot is

Explanation

Plasmin is the correct answer because it is an enzyme that specifically targets and breaks down fibrin, which is a protein involved in blood clot formation. By digesting fibrin, plasmin can effectively dissolve a clot and restore normal blood flow. Heparin is an anticoagulant that prevents clot formation but does not directly dissolve existing clots. Phosphokinase and fibrinase are not enzymes involved in clot dissolution. Thrombin is a clotting factor that promotes clot formation, so it is not the correct answer.

Submit
30. The sensory receptors of the semicircular canals are located in the

Explanation

The sensory receptors of the semicircular canals are located in the ampullae. The ampullae are small, bulbous structures found at the base of each semicircular canal. They contain hair cells, which are the sensory receptors responsible for detecting rotational movements of the head. When the head moves, the fluid inside the semicircular canals also moves, causing the hair cells in the ampullae to bend. This bending of the hair cells generates electrical signals that are sent to the brain, allowing us to perceive changes in our head position and maintain balance.

Submit
31. All of the following are true of neutrophils, except that they are

Explanation

Neutrophils, also known as polymorphonuclear leukocytes, are granular leukocytes that are highly active in fighting bacterial infections. They are phagocytic, meaning they can engulf and destroy pathogens. However, neutrophils are not directly involved in the process of coagulation, which is the formation of blood clots to prevent excessive bleeding. Therefore, the statement that neutrophils are important in coagulation is incorrect.

Submit
32. Movement of the endolymph in the semicircular canals

Explanation

The movement of the endolymph in the semicircular canals is responsible for signaling rotational movements. The semicircular canals are part of the inner ear and contain fluid-filled channels that detect changes in head rotation. When the head moves, the endolymph inside the canals also moves, stimulating hair cells that send signals to the brain. This allows us to perceive and sense rotational movements, such as spinning or turning.

Submit
33. Each heme ring in hemoglobin encloses an atom of

Explanation

Each heme ring in hemoglobin encloses an atom of iron. This is because iron is an essential component of hemoglobin, a protein found in red blood cells that is responsible for carrying oxygen throughout the body. Iron binds to oxygen in the lungs and releases it in tissues that need it. Without iron, hemoglobin would not be able to perform its vital function of transporting oxygen, leading to severe health issues such as anemia. Therefore, iron is the correct answer in this case.

Submit
34. Which of these proteins functions to store or transport iron?

Explanation

Hemoglobin, hemosiderin, and ferritin are all proteins that function to store or transport iron. Hemoglobin is found in red blood cells and carries oxygen to the body's tissues, while also helping to transport iron. Hemosiderin is a storage form of iron that is found in cells and tissues. Ferritin is another protein that stores iron and releases it when needed. Transferrin, on the other hand, is a protein that transports iron in the blood. Therefore, the correct answer is B, C, and D, as all of these proteins have a role in storing or transporting iron.

Submit
35. The hair cells of the utricle and saccule are clustered in

Explanation

The hair cells of the utricle and saccule are clustered in maculae. Maculae are specialized sensory areas located within the utricle and saccule of the inner ear. They contain hair cells that are responsible for detecting linear acceleration and head position relative to gravity. The hair cells in the maculae are embedded in a gelatinous material that contains small calcium carbonate crystals called otoconia. When the head moves, the otoconia shift and stimulate the hair cells, sending signals to the brain about the head's position and movement.

Submit
36. Some rat poisons contain a toxin that blocks the liver's abilithy to utilize vitamin K. Animals that consume this poison would die of

Explanation

Some rat poisons contain a toxin that blocks the liver's ability to utilize vitamin K. Vitamin K is essential for the production of clotting factors in the blood. When animals consume this poison, their liver cannot produce enough clotting factors, leading to a condition called hemorrhage. Hemorrhage refers to excessive bleeding, which can be fatal if left untreated. Therefore, animals that consume this poison would die of hemorrhage.

Submit
37. A person whose platelet count is 40,000/ul is suffering from

Explanation

A person with a platelet count of 40,000/ul is suffering from thrombocytopenia. Thrombocytopenia is a condition characterized by a low platelet count in the blood. Platelets are important for blood clotting, and a low count can lead to an increased risk of bleeding and bruising.

Submit
38. Hemolytic disease of the newborn may result if

Explanation

When an Rh-negative mother carries an Rh-positive fetus, there is a potential for hemolytic disease of the newborn. This is because the mother's immune system may produce antibodies against the Rh factor present in the fetal blood, which can then cross the placenta and attack the red blood cells of the fetus. This can lead to the destruction of the fetal red blood cells and cause various complications for the newborn, including anemia, jaundice, and potentially life-threatening conditions. Therefore, it is important for Rh-negative mothers to receive appropriate medical interventions, such as Rh immunoglobulin injections, to prevent the development of hemolytic disease of the newborn.

Submit
39. Perception of gravity and linear acceleration depends on

Explanation

The perception of gravity and linear acceleration depends on the force exerted by otoliths on hair cells of the maculae. Otoliths are tiny calcium carbonate crystals that are embedded in a gelatinous substance in the maculae of the inner ear. When the head moves, the otoliths shift, causing the gelatinous substance to move and bend the hair cells. This bending of hair cells sends signals to the brain, which helps us perceive changes in gravity and linear acceleration. Therefore, the force exerted by otoliths on hair cells is responsible for our perception of gravity and linear acceleration.

Submit
40. A moving blood clot is called a(n)

Explanation

A moving blood clot is called a thrombus. A thrombus is a blood clot that forms within a blood vessel and remains attached to the vessel wall. When a thrombus dislodges from its original site and travels through the bloodstream, it is called an embolus. A platelet plug is a temporary clot formed by platelets to stop bleeding. A plaque is a buildup of cholesterol and other substances in the walls of arteries. Procoagulant refers to substances that promote blood clotting.

Submit
41. Which of the following is true of eosinophils?

Explanation

Eosinophils constitute about 2 to 4 percent of white blood cells (WBCs). Allergic patients tend to have a higher number of eosinophils. Eosinophil granules stain with acid dyes. Eosinophils have a bilobed nucleus. Therefore, all of the statements are true about eosinophils.

Submit
42. The frequency of a perceived sound depends on 

Explanation

The frequency of a perceived sound depends on which part of the cochlear ducts is stimulated. This is because different parts of the cochlear ducts are responsible for detecting different frequencies of sound. The cochlear duct is divided into sections, with the base detecting high-frequency sounds and the apex detecting low-frequency sounds. When a specific part of the cochlear duct is stimulated, it sends signals to the brain that correspond to the frequency of the sound, allowing us to perceive different pitches.

Submit
43. The combination of plasma and formed elements is called

Explanation

The combination of plasma and formed elements is called whole blood because it refers to the complete mixture of both liquid and cellular components found in the circulatory system. Plasma is the liquid portion of blood, while formed elements include red blood cells, white blood cells, and platelets. Therefore, whole blood accurately describes the composition of blood as a whole.

Submit
44. Each of the following is a characteristic of whole blood except

Explanation

Whole blood has a higher viscosity than water due to the presence of various components such as red blood cells, white blood cells, platelets, and plasma proteins. These components contribute to the thickness and stickiness of blood, allowing it to flow through the blood vessels and form clots when necessary. Therefore, the given answer, "viscosity about the same as water," is incorrect as it contradicts the characteristics of whole blood.

Submit
45. When a person who lives at sea level vacations in the Rocky Mountains, you would expect

Explanation

When a person who lives at sea level vacations in the Rocky Mountains, they will experience a drop in oxygen levels due to the higher altitude. This drop in oxygen levels triggers the release of erythropoietin, a hormone that stimulates the production of red blood cells. As a result, there will be a rise in hematocrit, which is the percentage of red blood cells in the blood. Therefore, all three options A, B, and C are correct.

Submit
46. A person who has a low blood volume is said to be

Explanation

A person who has a low blood volume is said to be hypovolemic. This term refers to a condition where there is a decrease in the volume of blood circulating in the body. This can be caused by various factors such as excessive bleeding, dehydration, or fluid loss. Hypovolemia can lead to symptoms such as dizziness, low blood pressure, and rapid heart rate. Treatment for hypovolemia typically involves fluid replacement to restore the blood volume to a normal level.

Submit
47. The following is a list of vessels and structures that are associated with the heart 1) right atrium 2) left atrium 3) right ventricle 4) left ventricle 5) venae cavae 6) aorta 7) pulmonary trunk 8) pulmonary veins

Explanation

The vessels and structures associated with the heart are listed in the correct order as follows: venae cavae (5), right atrium (1), right ventricle (3), pulmonary trunk (7), pulmonary veins (8), left atrium (2), left ventricle (4), and aorta (6).

Submit
48. Blood returning to the heart from the pulmonary circuit first enters the

Explanation

When blood returns to the heart from the pulmonary circuit, it enters the left atrium. The pulmonary circuit is responsible for carrying deoxygenated blood from the heart to the lungs and oxygenated blood back to the heart. After the blood is oxygenated in the lungs, it travels through the pulmonary veins and enters the left atrium. From there, it passes through the left atrioventricular valve (also known as the mitral valve) into the left ventricle, where it is then pumped out to the rest of the body. Therefore, the correct answer is left atrium.

Submit
49. The following is a list of the steps that occur in the production of an auditory sensation. 1) the pressure wave distorts the basilar membrane on its way to the round window 2) movement of the tympanic membrane causes displacement of the malleus 3) Displacement of the stereocilia stimulates sensory neurons of the cochlear nerve 4) Movement of the malleus causes movement of the incus and stapes 5) Distortion of the basilar membrane forces the hair cells of the organ of Corti toward or away from the tectorial membrane 6) Movement of the oval window establishes pressure waves in the perilymph of the vesibular duct

Explanation

The correct order of the steps in the production of an auditory sensation is as follows:
1) Movement of the tympanic membrane causes displacement of the malleus (step 2)
2) Movement of the malleus causes movement of the incus and stapes (step 4)
3) Movement of the oval window establishes pressure waves in the perilymph of the vestibular duct (step 6)
4) Distortion of the basilar membrane forces the hair cells of the organ of Corti toward or away from the tectorial membrane (step 5)
5) Displacement of the stereocilia stimulates sensory neurons of the cochlear nerve (step 3)
Therefore, the correct order is 2,4,6,1,5,3.

Submit
50. Plasma proteins essential in body defense are the

Explanation

Immunoglobulins, also known as antibodies, are plasma proteins that play a crucial role in the body's defense against pathogens. They are produced by white blood cells and are involved in recognizing and neutralizing foreign substances such as bacteria, viruses, and toxins. Immunoglobulins are an essential component of the immune system and are responsible for providing immunity to various diseases.

Submit
51. The  process of lymphopoiesis goes on in all of the following organs, except

Explanation

Lymphopoiesis is the process of producing lymphocytes, which are a type of white blood cell involved in the immune response. This process primarily occurs in the red bone marrow, lymph nodes, spleen, and thymus. However, the kidney does not play a role in lymphopoiesis. The kidney's main function is to filter waste products from the blood and regulate fluid balance in the body. Therefore, it is not involved in the production of lymphocytes.

Submit
52. Which of the following descriptions best matches the term stereocilia

Explanation

Stereocilia are tiny hair-like structures found in the inner ear. When these stereocilia bend, they produce a receptor potential in hair cells. This bending of the stereocilia is an important mechanism for converting sound vibrations into electrical signals that can be interpreted by the brain.

Submit
53. Which of the following descriptions best matches the term otoliths?

Explanation

Otoliths are tiny weights necessary for the static sense of equilibrium. These are small calcium carbonate crystals that are found in the inner ear. When the head moves, the otoliths move as well, which stimulates the hair cells in the inner ear and helps us maintain balance and orientation. The movement of the otoliths is detected by the vestibular system, which provides information about the position of the head in relation to gravity. Therefore, otoliths play a crucial role in our ability to sense and maintain balance.

Submit
54. Tetanic muscle contractions don't occur in a normal cardiac muscle because

Explanation

Cardiac muscle contractions are regulated by a refractory period, which is the time during which the muscle cannot be stimulated again. In a normal cardiac muscle, the refractory period lasts until the muscle fully relaxes. This prevents tetanic muscle contractions, which are sustained and continuous contractions that can be harmful to the heart. Therefore, the correct answer is that the refractory period lasts until the muscle relaxes.

Submit
55. Plasma is closest in composition to

Explanation

Plasma is closest in composition to interstitial fluid because both of them are extracellular fluids found in the body. They have similar concentrations of ions, nutrients, gases, and waste products. Plasma is the liquid component of blood, while interstitial fluid surrounds and bathes the cells in tissues. This similarity in composition allows for the exchange of substances between plasma and interstitial fluid, facilitating the transport of nutrients and waste products to and from cells.

Submit
56. Granulocytes form in

Explanation

Granulocytes are a type of white blood cell that play a crucial role in the immune system's response to infection. They are formed in the red bone marrow, which is found in the spongy tissue inside bones. Red bone marrow is responsible for producing all types of blood cells, including granulocytes. The other options, such as the intestines, yellow bone marrow, spleen, and thymus, are not involved in the production of granulocytes.

Submit
57. The coronary sulcus is a groove that

Explanation

The coronary sulcus is a groove that marks the border between the atria and ventricles. This groove is located on the surface of the heart and separates the upper chambers (atria) from the lower chambers (ventricles). It serves as a boundary line between these two chambers, helping to distinguish their anatomical divisions.

Submit
58. When a rod is stimulated by light

Explanation

When a rod is stimulated by light, multiple changes occur in the cell. The retinal pigment, which is initially in the 11-cis form, undergoes a conformational change to the 11-trans form. This change triggers a cascade of events, leading to the hyperpolarization of the plasma membrane. As a result of hyperpolarization, less neurotransmitter is released from the rod cell. Additionally, the decrease in cGMP levels causes the closure of sodium channels. Therefore, all of the statements mentioned above are true and contribute to the response of a rod cell to light stimulation.

Submit
59. Stroke volume depends on

Explanation

Stroke volume is the amount of blood pumped out of the ventricles with each heartbeat. It depends on multiple factors, including the contractility of the ventricles, which refers to the strength of their contractions. Additionally, the pressure required to pump blood into the aorta also affects stroke volume, as it determines the resistance against which the ventricles must pump. Finally, end diastolic volume, which is the amount of blood in the ventricles at the end of diastole, also influences stroke volume. Therefore, all three factors (contractility, pressure, and end diastolic volume) contribute to determining stroke volume.

Submit
60. Plasma composes about               percent of whole blood and water composes              percent of the plasma volume

Explanation

Plasma is the liquid component of blood and makes up about 55% of whole blood. Water, in turn, composes about 92% of the volume of plasma.

Submit
61. The cusps (leaflets) of atrioventricular valves attach directly to

Explanation

The cusps (leaflets) of atrioventricular valves attach directly to chordae tendineae. Chordae tendineae are fibrous cords that connect the cusps of the valves to the papillary muscles, which are small muscles located in the walls of the ventricles. This connection helps to prevent the valves from inverting or prolapsing during the contraction of the heart.

Submit
62. Which of the following blood count values would be a sign of anemia?

Explanation

Anemia is a condition characterized by a decrease in the number of red blood cells (RBC) or a decrease in the amount of hemoglobin in the blood. A normal range for RBC count is typically around 4.5 to 5.5 million RBC per microliter of blood. Therefore, a count of 3.5 million RBC would be below the normal range and could be indicative of anemia. The other options, 400,000 platelets and 10,000 white blood cells (WBC), are not related to anemia. The last option, A and D taken together, is not a valid choice as only option D (3.5 million RBC) is relevant to anemia.

Submit
63. Contractions of the papillary muscles

Explanation

The contractions of the papillary muscles prevent the atrioventricular valves from reversing into the atria. When the ventricles contract, the papillary muscles also contract and pull on the chordae tendineae, which are attached to the atrioventricular valves. This prevents the valves from being pushed back into the atria, ensuring that blood flows in the correct direction from the atria into the ventricles.

Submit
64. Which of these descriptions best matches the term T lymphocytes?

Explanation

The term T lymphocytes refers to a type of immune cells that play a crucial role in coordinating and regulating the immune response. Helper cells are a specific type of T lymphocytes that assist in activating and directing other immune cells. This description best matches the term T lymphocytes because it accurately identifies helper cells as one type of T lymphocytes.

Submit
65. During ventricular systole, the

Explanation

During ventricular systole, the AV valves are closed. This is necessary to prevent the backflow of blood from the ventricles into the atria. When the ventricles contract, the pressure inside them increases, causing the AV valves to shut tightly. This closure ensures that blood is forced to flow out of the ventricles and into the aorta or pulmonary artery, rather than returning to the atria. Therefore, the closure of the AV valves is essential for the efficient pumping of blood during ventricular systole.

Submit
66. Eileen is a strict vegan and therefore eats no animal products. she develops an anemia that her doctor thinks is caused by a nutritional deficiency. Which of the following is the likeliest candidate?

Explanation

Eileen's strict vegan diet, which excludes all animal products, puts her at a higher risk for developing a vitamin B12 deficiency. Vitamin B12 is primarily found in animal-based foods, such as meat, fish, eggs, and dairy products. Since Eileen avoids these food sources, she may not be getting enough vitamin B12, leading to anemia. Intrinsic factor is a protein necessary for the absorption of vitamin B12, but its deficiency is less likely to be the cause of Eileen's anemia compared to the lack of vitamin B12 itself. The other options, vitamin B6 deficiency, vitamin K deficiency, and iron deficiency, are less likely to be the cause of Eileen's anemia based on the information provided.

Submit
67. As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit

Explanation

The long refractory period in the cardiac action potential prevents the cardiac muscle from experiencing fatigue. During the refractory period, the muscle is unable to respond to further stimulation, allowing it to rest and recover before the next contraction. This ensures that the heart muscle can continue to contract efficiently and without fatigue, maintaining its pumping function.

Submit
68. The following are structural components of the conducting system of the heart. 1) Purkinje fibers 2) AV bundle 3) AV node 4) SA node 5) bundle branches the sequence in which excitation would move through this system is

Explanation

The correct sequence in which excitation would move through the conducting system of the heart is 4,3,2,5,1. The excitation starts at the SA node (4), which is the natural pacemaker of the heart. From there, it moves to the AV node (3), which acts as a gatekeeper and delays the electrical signal to allow the atria to contract fully before the ventricles are stimulated. The signal then travels through the AV bundle (2), which is also known as the bundle of His, and divides into the bundle branches (5). Finally, the excitation spreads through the Purkinje fibers (1), which are specialized cardiac muscle fibers that rapidly distribute the electrical signal to the ventricular muscle cells, causing them to contract.

Submit
69.                     is a condition in which the oxygen-carrying capacity of the blood is reduced.

Explanation

Anemia is a condition in which the oxygen-carrying capacity of the blood is reduced. This can occur due to a decrease in the number of red blood cells or a decrease in the amount of hemoglobin in the blood. Anemia can result from various causes such as nutritional deficiencies, chronic diseases, genetic disorders, or blood loss. Symptoms of anemia may include fatigue, weakness, shortness of breath, pale skin, and dizziness. Treatment for anemia depends on the underlying cause and may involve iron supplementation, blood transfusions, or medications.

Submit
70. Pernicious anemia caused by a lack of intrinsic factor is specifically treated by

Explanation

Pernicious anemia is caused by a lack of intrinsic factor, which is necessary for the absorption of vitamin B12. Therefore, the specific treatment for this condition is injections of vitamin B12. Iron deficiency anemia, on the other hand, is treated with oral doses of iron. Blood transfusion may be necessary in severe cases of anemia, but it is not the specific treatment for pernicious anemia caused by a lack of intrinsic factor. Injections of iron would also not be effective in treating this condition.

Submit
71. The visceral pericardium is the same as the

Explanation

The epicardium is the outermost layer of the heart and is also known as the visceral pericardium. It is a thin layer that covers the surface of the heart and is composed of connective tissue and a layer of epithelial cells. The epicardium provides protection to the heart and helps to reduce friction as the heart beats. It is separate from the parietal pericardium, which is the outer layer of the pericardium that surrounds the heart, and is also distinct from the other layers of the heart, such as the myocardium and endocardium.

Submit
72. When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as a(n)

Explanation

When a blood clot forms on a ruptured plaque in a coronary artery, it is referred to as coronary thrombosis. This condition occurs when the inner lining of the artery is damaged, causing the formation of a blood clot that can block the flow of blood to the heart muscle. Coronary thrombosis is a serious condition that can lead to a heart attack or myocardial infarction if not treated promptly. Angina pectoris refers to chest pain or discomfort caused by reduced blood flow to the heart muscle, coronary spasm is a sudden constriction of the coronary artery, and pulmonary embolism is a blockage in the arteries of the lungs.

Submit
73. Most of the middle layer in the heart wall is composed of

Explanation

The correct answer is cardiac myocytes. Cardiac myocytes are specialized muscle cells found in the middle layer of the heart wall, known as the myocardium. These cells are responsible for the contraction of the heart, allowing it to pump blood throughout the body. Unlike other types of muscle cells, cardiac myocytes have a unique structure that allows them to transmit electrical signals and contract in a coordinated manner. Therefore, they play a crucial role in maintaining the normal functioning of the heart.

Submit
74. David suffers from a prolapsed mitral valve. This condition would cause

Explanation

A prolapsed mitral valve refers to the displacement of the valve leaflets into the left atrium during systole. This condition can lead to regurgitation of blood from the left ventricle into the left atrium, causing increased effort by the left ventricle to pump blood effectively. The regurgitation can also result in turbulent blood flow, leading to the production of a systolic murmur. Therefore, both options B and C (increased effort by the left ventricle and systolic murmur) are correct.

Submit
75. Compared to the right ventricle, the left ventricle has all the following characteristics, except that it

Explanation

The left ventricle has all the listed characteristics except for pumping a greater volume. The left ventricle actually pumps a greater volume of blood compared to the right ventricle. It has a thicker wall, produces higher pressure when it contracts, and works harder. Additionally, it is not mentioned that the left ventricle is round in cross section, so it cannot be assumed that it is a characteristic of the left ventricle.

Submit
76. The developmental stage at which erythrocytes enter the circulation is as

Explanation

Reticulocytes are immature red blood cells that still contain some RNA and organelles. They are released into the bloodstream from the bone marrow during the final stages of erythropoiesis, the process of red blood cell production. Reticulocytes then mature into fully functional erythrocytes, or red blood cells, within 1-2 days. Therefore, reticulocytes are the developmental stage at which erythrocytes enter the circulation.

Submit
77. The percent fraction of formed elements relative to whole blood is the

Explanation

Hematocrit refers to the percentage of formed elements (red blood cells, white blood cells, and platelets) in relation to the total volume of blood. It is a measure of the packed volume of these formed elements in the blood. This value is important in diagnosing and monitoring conditions such as anemia and polycythemia.

Submit
78. An increase in the rate of action potentials from baroreceptors will reflexly lead to

Explanation

An increase in the rate of action potentials from baroreceptors indicates a high blood pressure. In response to this, the body initiates a reflex action to restore homeostasis. The reflex action includes both a decrease in heart rate and a decrease in blood pressure. Therefore, the correct answer is both B and C.

Submit
79. A typical adult hematocrit is

Explanation

The correct answer is 45. Hematocrit is a measure of the volume percentage of red blood cells in the total blood volume. A typical adult hematocrit ranges between 40-54% for men and 37-47% for women. Therefore, a hematocrit of 45 would fall within the normal range for both men and women.

Submit
80. Which of these would cause stroke volume to increase?

Explanation

When diastolic blood pressure is decreased, it allows for more time for the ventricles to fill with blood during diastole. This increased filling time leads to a greater volume of blood being ejected with each contraction, resulting in an increase in stroke volume.

Submit
81. Analysis of the electrocardiogram can reveal all of the folliwng, except the

Explanation

The electrocardiogram (ECG) is a test that measures the electrical activity of the heart. It provides information about the heart rate, duration of the ventricular action potential, effects of drugs and poisons, and the condition of the conducting system. However, it does not directly measure the stroke volume, which is the amount of blood pumped out of the heart with each beat. Stroke volume is typically measured using other techniques such as echocardiography or cardiac catheterization. Therefore, the correct answer is stroke volume.

Submit
82. Consider these results from a blood lab test. Which value is most likely abnormal?

Explanation

The most likely abnormal value in this blood lab test is the hemoglobin level of 10.7 g/100ml. Hemoglobin is a protein in red blood cells that carries oxygen throughout the body. Normal hemoglobin levels typically range from 12 to 16 g/100ml for women and 13.5 to 17.5 g/100ml for men. A hemoglobin level of 10.7 g/100ml is below the normal range, indicating a potential abnormality or deficiency in red blood cells or oxygen-carrying capacity.

Submit
83. AV nodal cells are poorly interconnected compared to contractile cells but they have bigger diameters

Explanation

The first part of the statement is true because AV nodal cells are indeed poorly interconnected compared to contractile cells. However, the second part of the statement is false because AV nodal cells actually have smaller diameters compared to contractile cells, not bigger diameters.

Submit
84. The first  blood vessels to branch from the aorta are the                arteries

Explanation

The first blood vessels to branch from the aorta are the coronary arteries. These arteries supply oxygenated blood to the heart muscle itself. They are essential for maintaining the heart's function and ensuring proper circulation throughout the body. Without the coronary arteries, the heart would not receive the necessary oxygen and nutrients it needs to pump blood effectively. Therefore, the coronary arteries are crucial for overall cardiovascular health.

Submit
85. Which of the following descriptions applies/apply to the term myopia?

Explanation

The term myopia refers to nearsightedness, where a person can see objects clearly up close but has difficulty seeing objects far away. This is because the image is focused in front of the retina instead of directly on it. Myopia can be corrected with a diverging lens, which helps to shift the focus of the image onto the retina. Therefore, all of the descriptions A, B, and C apply to the term myopia.

Submit
86. If a patient's tricuspid valve was leaking during systole, what would happen?

Explanation

If a patient's tricuspid valve is leaking during systole, it would result in regurgitation into the right atrium. This means that during the contraction phase of the heart (systole), some of the blood that should be pumped forward into the pulmonary artery instead flows back into the right atrium. This can lead to symptoms such as fluid accumulation in the body, enlargement of the right atrium, and potentially heart failure. The options A and B only are correct because regurgitation into the superior vena cava is not a direct consequence of tricuspid valve leakage during systole.

Submit
87. In which of the following cases would the focal distance be greater?

Explanation

A flat lens would have a greater focal distance compared to a round lens. This is because a flat lens has a flatter curvature, which means that the rays of light passing through it would converge at a greater distance from the lens. In contrast, a round lens has a more curved shape, causing the rays of light to converge at a shorter distance. Therefore, a flat lens would have a greater focal distance.

Submit
88. Depolarization of teh atria corresponds to the EKG's

Explanation

The correct answer is P wave. The P wave represents the depolarization of the atria on an EKG. It is the first deflection seen on the EKG and indicates the electrical activity that initiates the contraction of the atria.

Submit
89. A sudden rise of room brightness would cause

Explanation

A sudden rise of room brightness would cause all of the above. When there is a sudden increase in brightness, the sphincter pupillary muscles contract, leading to a decrease in the size of the pupil. This contraction also causes a conversion of the retinal structure. Additionally, the radial pupillary muscles contract in response to the increased light, further contributing to the decrease in pupil size.

Submit
90. The P wave of the electrocardiogram is a signal from

Explanation

The P wave of the electrocardiogram represents the depolarization of the atria. Depolarization refers to the electrical activation of the cardiac muscle cells, causing them to contract. In the heart, the electrical signal originates from the sinoatrial (SA) node, which is located in the right atrium. This signal spreads through the atria, causing them to depolarize and contract. The depolarization of the atria is represented by the P wave on the electrocardiogram. Therefore, the correct answer is depolarization of the atria.

Submit
91. Which of the following descriptions best matches the term ossicles?

Explanation

The term "ossicles" refers to the tiny bones in the middle ear that transmit sound vibrations from the tympanic membrane (eardrum) to the inner ear. They consist of three bones: the malleus (hammer), incus (anvil), and stapes (stirrup). These bones work together to amplify and transmit sound waves, allowing them to be converted into electrical signals that can be interpreted by the brain. Therefore, the description "transmit movement of the tympanic membrane to the inner ear" best matches the term ossicles.

Submit
92. Which of the following is greater during left ventricular systole?

Explanation

During left ventricular systole, the ventricle contracts and pumps blood into the aorta. This contraction leads to an increase in pressure within the ventricle, known as the peak pressure in the ventricle. The aorta also experiences an increase in pressure, but it is not greater than the peak pressure in the ventricle. Therefore, the correct answer is the peak pressure in the ventricle.

Submit
93. Megan has an infected puncture would to her foot. Which type of white blood cell would you expect to be elevated in a differential white cell count?

Explanation

Neutrophils are the most abundant type of white blood cells and are known for their role in fighting bacterial infections. In the case of an infected puncture wound, neutrophils would be expected to be elevated in a differential white cell count. They are responsible for engulfing and destroying bacteria, and their increased presence indicates an immune response to the infection.

Submit
94. If the connection between the vagus nerve and the heart is cut, which of these changes will occur?

Explanation

If the connection between the vagus nerve and the heart is cut, none of the mentioned changes will occur. The vagus nerve is responsible for regulating the parasympathetic control of the heart, which helps to slow down the heart rate and decrease cardiac output. However, if the connection is cut, the parasympathetic control will be lost, but other factors such as sympathetic control will still be able to regulate the heart rate and maintain normal functioning. Therefore, there will be no significant changes in nodal fiber depolarization, cardiac output, heart rate, or stroke volume.

Submit
95. In adults, the only site of red blood cell production, and the primary site of white blood cell formation, is the

Explanation

Red bone marrow is the only site of red blood cell production in adults, as well as the primary site of white blood cell formation. The spleen, yellow bone marrow, liver, and thymus do not have the capability to produce red blood cells or serve as the primary site for white blood cell formation.

Submit
96. Cardiac output is increased by

Explanation

Sympathetic stimulation increases cardiac output by increasing the heart rate and contractility of the heart. This leads to an increased stroke volume, which is the amount of blood pumped out of the heart with each beat. Increased end systolic volume, on the other hand, would actually decrease cardiac output as it represents the amount of blood remaining in the heart at the end of systole. Therefore, the correct answer is "more sympathetic stimulation" as it directly increases cardiac output.

Submit
97. Which of the following descriptions best matches the term aqueous humor?

Explanation

The term "aqueous humor" refers to the gelatinous fluid that fills the anterior chamber of the eye. It is not converted to vitreous humor with age or secreted in bright light. However, excessive production of aqueous humor can indeed lead to glaucoma, a condition characterized by increased pressure within the eye. Therefore, the correct answer is "excessive production may lead to glaucoma."

Submit
98. The external accoustic meatus ends at

Explanation

The external acoustic meatus, also known as the ear canal, is a tube that leads from the outer ear to the middle ear. It ends at the tympanic membrane, which is commonly referred to as the eardrum. The tympanic membrane is a thin, delicate membrane that vibrates in response to sound waves and transmits them to the middle ear. Therefore, the correct answer is "the tympanic membrane."

Submit
99. Which of the following would be greater?

Explanation

The end-diastolic volume refers to the amount of blood present in the ventricles of the heart at the end of the relaxation phase (diastole) of the cardiac cycle. When the heart rate is higher at 150 beats per minute, the heart has less time to fill with blood during diastole. As a result, the end-diastolic volume is likely to be lower compared to when the heart rate is slower at 60 beats per minute. Therefore, the end-diastolic volume when the heart rate is 60 beats per minute would be greater than when the heart rate is 150 beats per minute.

Submit
100. If there is a complete block between teh SA node and the AV node, how would the ECD be affected?

Explanation

If there is a complete block between the SA node and the AV node, the electrical conduction through the heart will be disrupted. This means that the atria and ventricles will beat independently of each other. As a result, the rate of P waves (atrial contractions) will be faster than the rate of QRS complexes (ventricular contractions). This is because the SA node, which normally controls the heart rate, is no longer able to regulate the ventricular contractions. Therefore, the P waves will occur at a faster rate than the QRS complexes.

Submit
101. Depolarization of the ventricles is represented on an electrocardiogram by the

Explanation

The QRS complex represents the depolarization of the ventricles on an electrocardiogram. Depolarization is the electrical activation of the heart muscle, which leads to the contraction of the ventricles and the pumping of blood. The QRS complex consists of three waves: Q, R, and S. It represents the spread of electrical activity through the ventricles, causing them to contract and pump blood. The P wave, on the other hand, represents the depolarization of the atria, while the T wave represents the repolarization of the ventricles. The PR complex and S wave are not accurate representations of ventricular depolarization.

Submit
102. The T wave on an ECG tracing represents

Explanation

The T wave on an ECG tracing represents ventricular repolarization. This means that the ventricles, which are the lower chambers of the heart, are resetting their electrical state in preparation for the next heartbeat. Atrial repolarization occurs at the same time as the QRS complex, while ventricular depolarization occurs during the QRS complex. Ventricular contraction is represented by the QRS complex, and atrial depolarization is represented by the P wave. Therefore, the correct answer is ventricular repolarization.

Submit
103. What effect would compressing the inferior vena cava just below the diaphragm have on cardiac function?

Explanation

Compressing the inferior vena cava just below the diaphragm would have an effect on cardiac function by increasing cardiac output and increasing sympathetic stimulation of the heart. This is because compressing the inferior vena cava would impede the return of blood to the heart, leading to a decrease in preload and an increase in sympathetic stimulation to compensate for the decreased cardiac output. This would result in an increase in both cardiac output and sympathetic stimulation of the heart.

Submit
104. Bill wants to determine his blood type, so he takes a few drops of blood from a puncture wound in his finger and mixes it with various antisera. His blood cells agglutinate when mixed with the anti-A sera but not with the anti-B or anti-D sera. This means

Explanation

Based on the given information, Bill's blood cells agglutinate when mixed with anti-A sera but not with anti-B or anti-D sera. This indicates that Bill has antigens for blood type A, but not for blood type B or the Rh factor. Therefore, Bill could receive type A-negative blood in a transfusion, as type A-negative blood does not have the B antigen that could cause agglutination in Bill's blood.

Submit
105. Which of the following descriptions best matches the term basilar membrane?

Explanation

The basilar membrane is a structure located in the cochlea of the inner ear. It is responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. When the stapes (one of the three small bones in the middle ear) moves back and forth in response to sound waves, the basilar membrane moves up and down. This motion stimulates the hair cells on the basilar membrane, allowing them to detect different frequencies of sound.

Submit
106. The first heart sound is heard when the

Explanation

The first heart sound is heard when the semilunar valves close. This sound is known as the "lub" sound and occurs during the systole phase of the cardiac cycle. When the ventricles contract and pump blood out of the heart, the pressure inside the ventricles increases. As a result, the semilunar valves, which are located between the ventricles and the aorta/pulmonary artery, close to prevent the backflow of blood. This closure creates a sound that can be heard as the first heart sound.

Submit
107. During the isovolumetric phase of ventricular systole, the

Explanation

During the isovolumetric phase of ventricular systole, the atrioventricular valves and semilunar valves are closed. This means that the blood is not being ejected into the great vessels yet, and both the atria and ventricles are in a state of contraction and relaxation respectively. This phase allows for the buildup of pressure within the ventricles before the semilunar valves open and blood is ejected into the great vessels.

Submit
108. An obstruction in blood flow to the kidneys would ultimately result in

Explanation

An obstruction in blood flow to the kidneys would ultimately result in increased erythropoiesis. This is because the kidneys produce a hormone called erythropoietin, which stimulates the production of red blood cells in the bone marrow. When blood flow to the kidneys is obstructed, the kidneys may not receive enough oxygen, leading to the release of more erythropoietin to stimulate the production of more red blood cells. This increased erythropoiesis helps to compensate for the decreased oxygen supply and maintain adequate oxygen levels in the body.

Submit
109. During the cardiac cycle, the

Explanation

Both options B and D are correct. Option B states that the QRS complex of the ECG precedes the increase in ventricular pressure, which is true. The QRS complex represents ventricular depolarization, which occurs before ventricular contraction and the subsequent increase in pressure. Option D states that the first heart sound coincides with the QRS complex of the ECG, which is also true. The first heart sound, or S1, is caused by the closure of the mitral and tricuspid valves, which occurs during ventricular systole, coinciding with the QRS complex on the ECG.

Submit
110. The              conveys information about head position with respect to gravity

Explanation

Both the utricle and saccule are parts of the vestibular system in the inner ear. They contain sensory cells that detect the position of the head with respect to gravity. This information is important for maintaining balance and coordinating movements. The ampulla and cochlea are not involved in detecting head position with respect to gravity.

Submit
111. The volume of blood ejected from each ventricle during a contraction is called the

Explanation

The volume of blood ejected from each ventricle during a contraction is called the cardiac output. This term refers to the amount of blood that is pumped out by the heart per minute. It is calculated by multiplying the stroke volume (the volume of blood ejected from each ventricle with each contraction) by the heart rate (the number of contractions per minute). Therefore, cardiac output represents the overall efficiency of the heart in pumping blood throughout the body.

Submit
112. The cornea is part of the

Explanation

The cornea is a transparent, dome-shaped structure located at the front of the eye. It is a part of the fibrous tunic, which is the outermost layer of the eye. The fibrous tunic provides structural support and protection to the eye. The cornea plays a crucial role in focusing light onto the retina, allowing clear vision. Therefore, it is correct to say that the cornea is part of the fibrous tunic.

Submit
113. Which of the following is not true of monocytes?

Explanation

Monocytes are a type of white blood cell that can differentiate into macrophages. They are able to phagocytize bacteria and enter tissues to wander and perform their functions. However, it is not true that monocytes are long lived. Monocytes have a relatively short lifespan in the bloodstream, typically ranging from a few hours to a few days, before they migrate into tissues and differentiate into macrophages. Therefore, the statement that monocytes are long lived is incorrect.

Submit
114. Each of the following factors will increase cardiac output, except

Explanation

Increased parasympathetic stimulation is not expected to increase cardiac output. Parasympathetic stimulation typically slows down the heart rate and decreases cardiac output. On the other hand, increased heart rate, increased sympathetic stimulation, increased venous return, or a combination of increased heart rate and increased sympathetic stimulation can all lead to an increase in cardiac output.

Submit
115. The cardioacceleratory center activates sympathetic neurons and the cardioinhibitory center controls parasympathetic neurons

Explanation

Not sure on this one

Submit
116. "An increase in end-diastolic volume increases the stroke volume" is a way of stating

Explanation

Starling's law of the heart states that the stroke volume of the heart increases with an increase in end-diastolic volume. This means that when the heart is filled with a larger volume of blood during diastole (relaxation phase), it will contract more forcefully during systole (contraction phase), resulting in a higher stroke volume. This law describes the relationship between the stretching of cardiac muscle fibers and the force of contraction, highlighting the heart's ability to adapt and pump more blood in response to increased venous return.

Submit
117. Gustatory receptors are sensitive to dissolved chemicals but insensitive to light. This is due to

Explanation

The correct answer is receptor specificity. Gustatory receptors are specialized to detect and respond to specific dissolved chemicals in the mouth, such as taste molecules. They are not sensitive to light because their function is specifically related to taste perception. This specificity allows them to accurately distinguish between different tastes and contribute to our overall sensory experience of food and beverages.

Submit
118. The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the

Explanation

During the systolic ejection phase, the mitral valve is closed and the aortic valve is open. This phase occurs when the ventricles contract and pump blood out of the heart into the aorta. The closure of the mitral valve prevents backflow of blood into the atrium, while the opening of the aortic valve allows blood to be ejected into the systemic circulation. Therefore, the systolic ejection phase is the correct answer.

Submit
119. Olfactory glands

Explanation

The olfactory glands coat the olfactory epithelium with a pigmented mucus. This mucus helps to trap and dissolve odor molecules, allowing them to be detected by the olfactory receptors in the epithelium. The pigmented mucus also helps to protect the delicate olfactory cells from damage and provides moisture for optimal functioning.

Submit
120. The mucus that covers the olfactory epithelium does all of the following, except that it

Explanation

The mucus that covers the olfactory epithelium performs several functions. It keeps the tissue moist, keeps the tissue free of particles, provides a medium to dissolve odorants, and dilutes potentially dangerous odorants. However, it does not dissolve unwanted chemicals and wash them away.

Submit
121. All of the following are true of olfactory pathways, except

Explanation

The olfactory pathways do not project first to the mamillary bodies and then to the thalamus. Instead, olfactory information is first processed in the olfactory bulb, where primary afferents synapse. From there, the olfactory pathways project directly to the olfactory cortex and limbic system, bypassing the thalamus. This is unique compared to other sensory pathways, which typically synapse in the thalamus before reaching the cortex. The mamillary bodies are not directly involved in olfactory processing.

Submit
122. All of the following are true of the lacrimal glands except that they

Explanation

The lacrimal glands produce watery, slightly alkaline secretions, which means that they do not produce a strongly hypertonic fluid. Hypertonic fluids have a higher concentration of solutes compared to the surrounding fluid, while the lacrimal glands produce a fluid that is more similar in concentration to tears. The other statements are true about the lacrimal glands: they produce lysozyme, are located in recesses in the frontal bones, and produce most of the volume of tears.

Submit
123. Gustatory receptors are located

Explanation

Gustatory receptors are located on the surface of the tongue because the tongue plays a crucial role in the sense of taste. These receptors, also known as taste buds, contain specialized cells that are responsible for detecting different flavors such as sweet, sour, salty, and bitter. When food or drink comes into contact with the taste buds on the tongue, the gustatory receptors send signals to the brain, allowing us to perceive and distinguish various tastes. Therefore, the surface of the tongue is the primary location for gustatory receptors to facilitate the sense of taste.

Submit
124. The palpebrae are connected at the

Explanation

The palpebrae refers to the eyelids, which are the movable folds of skin that cover and protect the eyes. They play a crucial role in blinking and spreading tears across the surface of the eye. Therefore, it is logical to conclude that the correct answer is "eyelids" as they are the anatomical structure being referred to in the question.

Submit
125. Olfactory receptors send axons through the cribriform plate. They synapse on neurons in the

Explanation

The olfactory receptors send axons through the cribriform plate and synapse on neurons in the olfactory bulb. The olfactory bulb is responsible for processing and relaying olfactory information to other areas of the brain, such as the cerebral cortex. Therefore, the olfactory bulb is the correct answer as it is the initial site where olfactory information is processed before being transmitted to other brain regions.

Submit
126. Abnormally slow depolarization of the ventricles would most change the shape of the                    in and ECG tracing.

Explanation

Abnormally slow depolarization of the ventricles would most likely change the shape of the QRS complex in an ECG tracing. The QRS complex represents the depolarization of the ventricles, so if this process is slowed down, it would cause a noticeable change in the shape of the QRS complex. The QRS complex is typically a sharp, narrow peak, but with a slow depolarization, it may become wider and more prolonged. This change in shape can provide valuable information about the functioning of the ventricles and can help diagnose certain cardiac conditions.

Submit
127. People with type AB blood are considered the "universal recipient" for transfusions because

Explanation

People with type AB blood are considered the "universal recipient" for transfusions because their blood lacks A or B agglutinins. Agglutinins are antibodies that can cause clumping or agglutination of red blood cells. Since type AB blood does not have these antibodies, it can receive blood from any other blood type without the risk of agglutination. This makes type AB blood compatible with all other blood types, hence why it is considered the universal recipient.

Submit
128. Which of the following is true about rhodopsin?

Explanation

Rhodopsin is the visual pigment found in the rods of the retina. It is also known as visual purple. During photoreception, rhodopsin undergoes bleaching. Rhodopsin is composed of opsin, a protein, and retinal, a light-sensitive molecule. Therefore, all of the given statements about rhodopsin are true.

Submit
129. A pigment synthesized from vitamin A is

Explanation

cGMP (cyclic guanosine monophosphate) is a molecule synthesized from vitamin A that plays a crucial role in the visual signaling pathway. It acts as a second messenger in the phototransduction process within the retina. When light hits the retina, it causes a change in the shape of the pigment molecule called retinal, which is derived from vitamin A. This change in shape activates the protein opsin, forming a complex called rhodopsin. Rhodopsin then activates transducin, a G-protein, which leads to the production of cGMP. The decrease in cGMP levels triggers a cascade of events that ultimately result in the generation of electrical signals for vision.

Submit
130. During the T wave of the electrocardiogram, the ventricles are

Explanation

During the T wave of the electrocardiogram, the ventricles are repolarizing and relaxing. Repolarization refers to the process of restoring the electrical charge of the cardiac cells back to their resting state after depolarization, which occurs during the QRS complex. Relaxation, on the other hand, refers to the relaxation of the ventricles after contraction, which occurs during the QRS complex as well. Therefore, both options B and D are correct.

Submit
131. All of the following are true of the fibrous tunic of the eye, except that it

Explanation

The fibrous tunic of the eye consists of the sclera, limbus, and cornea, provides mechanical support and some protection for the eye, and is where extrinsic eye muscles insert. However, it does not produce aqueous humor. The production of aqueous humor occurs in the ciliary body, which is part of the vascular tunic of the eye.

Submit
132. Which of the following is true of the vascular tunic of the eye?

Explanation

The vascular tunic of the eye, also known as the uvea, is responsible for controlling the shape of the lens, providing a route for blood vessels and lymphatics that supply tissues of the eye, regulating the amount of light entering the eye, and secreting and reabsorbing the aqueous humor. Therefore, the statement "all of the above" is true as it encompasses all the functions of the vascular tunic of the eye.

Submit
133. People who suffer from hemophilia A fail to produce a functional Factor VIII; as a result

Explanation

People who suffer from hemophilia A lack a functional intrinsic pathway. Hemophilia A is a genetic disorder characterized by a deficiency or absence of Factor VIII, which is an essential clotting factor in the intrinsic pathway of the coagulation cascade. Without a functional intrinsic pathway, individuals with hemophilia A experience difficulties in forming blood clots, leading to prolonged coagulation times. The extrinsic pathway, on the other hand, is not affected in hemophilia A. Therefore, the correct answer is that they lack a functional intrinsic pathway.

Submit
134. The palpebrae

Explanation

The palpebrae, also known as the eyelids, have multiple functions. They cover and protect the eye, acting as a barrier against foreign objects and excessive light. The palpebrae also contain tarsal glands, which secrete oils that help lubricate the eye and prevent dryness. Additionally, the palpebrae are controlled by cranial nerves, specifically the oculomotor nerve, which allows for voluntary and involuntary movements of the eyelids. Therefore, options A, B, and C are all correct explanations for the functions and characteristics of the palpebrae.

Submit
135. Pupillary muscle groups are controlled by the ANS. Parasympathetic activation causes pupillary               and sympathetic activation causes             .

Explanation

Parasympathetic activation causes pupillary constriction, while sympathetic activation causes pupillary dilation.

Submit
136. Which of the following statements concerning vision is false?

Explanation

The statement that the entire retina receives equal representation in the visual cortex is false. In reality, the central portion of the retina, known as the fovea, receives a disproportionately large representation in the visual cortex compared to the peripheral areas of the retina. This is because the fovea contains a higher density of cone cells, which are responsible for detailed and color vision. Therefore, the visual cortex devotes more neural resources to process information from the fovea, resulting in a larger representation in the brain.

Submit
137. A structure that is located at the medial canthus and contains glands that contribute to a gritty deposit is the

Explanation

The lacrimal caruncle is a structure located at the medial canthus of the eye. It contains glands that produce a gritty deposit called rheum, which can accumulate in the corners of the eyes. The conjunctiva is a thin, clear membrane that covers the front surface of the eye and inner surface of the eyelids. A chalazion is a blocked oil gland on the eyelid that causes a painless bump. The meibomian glands are located along the eyelid margin and secrete oil to lubricate the eye. The palpebra refers to the eyelid.

Submit
138. Which of the following procudes a lipid-rich secretion that prevents the upper and lower eyelids from sticking together at their edges?

Explanation

The tarsal gland produces a lipid-rich secretion that prevents the upper and lower eyelids from sticking together at their edges. This secretion, known as meibum, helps to lubricate the surface of the eye and prevent tear evaporation. The palpebra, lacrimal caruncle, conjunctiva, and chalazion do not have this specific function of producing a lipid-rich secretion to prevent the eyelids from sticking together.

Submit
139. The process of fibrinolysis

Explanation

Fibrinolysis is the process in which fibrinogen, a protein involved in blood clotting, is activated. This activation helps in dissolving clots and forming emboli. Additionally, fibrinolysis also plays a role in drawing torn edges of damaged tissue closer together. However, it does not directly form thrombi, which are blood clots that can block blood vessels.

Submit
140. The vitreous humor

Explanation

The vitreous humor helps to stabilize the eye and give physical support to the retina. This is because the vitreous humor fills the posterior cavity of the eye, providing a cushioning effect and helping to maintain the shape of the eyeball. Additionally, it helps to support the delicate retina, which is responsible for converting light into electrical signals that can be interpreted by the brain. Therefore, options B and C are correct.

Submit
141. Pacemaker cells in the SA node

Explanation

The correct answer is both B and C. Pacemaker cells in the SA node show a slow spontaneous depolarization, which means they gradually become more positive and reach a threshold to initiate an action potential. Additionally, these cells are connected by gap junctions to atrial myocytes, allowing for the coordinated contraction of the atria. Therefore, both statements B and C are true.

Submit
142. The                   covers most of the exposed surface of the eye

Explanation

The conjunctiva is a thin, transparent membrane that covers the front surface of the eye and lines the inside of the eyelids. It helps to protect the eye from foreign particles, lubricates the eye by producing tears, and plays a role in maintaining the health of the eye. It covers most of the exposed surface of the eye, making it the correct answer.

Submit
143. The gelatinous material that gives the eyeball its basic shape is the

Explanation

The vitreous humor is a gel-like substance that fills the posterior cavity of the eyeball, giving it its basic shape. It helps maintain the shape of the eyeball and provides support to the delicate structures within the eye. The vitreous humor also helps transmit light to the retina at the back of the eye, allowing for clear vision.

Submit
144. Which of these descriptions best matches the term eosinophils?

Explanation

Eosinophils are a type of white blood cells that are often elevated in allergic individuals. They play a role in the immune response to parasites and are involved in allergic reactions and asthma.

Submit
145. The transparent portion of the fibrous tunic is the

Explanation

The iris is the correct answer because it is the colored portion of the eye that surrounds the pupil. It is responsible for controlling the size of the pupil and thus regulating the amount of light that enters the eye. The iris is located in the anterior part of the eye and is visible through the transparent cornea.

Submit
146. The first heart sound ("lub")

Explanation

The first heart sound, also known as "lub," is associated with the closing of the aortic valve. This sound occurs during ventricular systole when the ventricles contract and push blood out of the heart. As the ventricles contract, the pressure inside them rises, causing the aortic valve to close. The closing of the valve produces the "lub" sound, which can be heard as the blood is forced against the closed valve.

Submit
147. The part of the eye that determines eye color is the

Explanation

The pupil is the correct answer because it is the part of the eye that determines eye color. The color of the iris, which surrounds the pupil, is what gives the eye its color. The size of the pupil can vary, depending on the amount of light entering the eye, but it does not affect the eye color itself. Therefore, the pupil is the correct choice for this question.

Submit
148. If the connection between the SA node and AV node becomes blocked

Explanation

When the connection between the SA node and AV node becomes blocked, the electrical signals that coordinate the heart's contractions are disrupted. The SA node is responsible for initiating the electrical impulses that cause the heart to beat, and the AV node is responsible for transmitting these impulses to the ventricles. When the connection is blocked, the ventricles will not receive the signals as efficiently, leading to a slower heartbeat. Therefore, the ventricles will beat more slowly in this situation.

Submit
149. The opening in the iris through which light passes is the

Explanation

The pupil is the correct answer because it is the opening in the iris through which light passes. The iris is the colored part of the eye that controls the size of the pupil, allowing more or less light to enter the eye. The cornea is the clear front surface of the eye, the conjunctiva is the thin, clear tissue that covers the white part of the eye, and the anterior and posterior chambers are spaces filled with fluid in the eye. Therefore, none of these options are the correct answer.

Submit
150. The space between the cornea and the iris is the

Explanation

The space between the cornea and the iris is called the anterior segment or chamber. This space is filled with a clear fluid called aqueous humor. The anterior segment is responsible for maintaining the shape of the eyeball and providing nutrients to the cornea and lens. It also helps in maintaining the intraocular pressure and plays a role in the focusing of light onto the retina. The other options mentioned, such as the posterior cavity, vitreous segment, and pupil, are not accurate descriptions of the space between the cornea and the iris.

Submit
151. The space between the iris and ciliary body and the lens is the

Explanation

The space between the iris and ciliary body and the lens is known as the posterior chamber or segment. This space is filled with a clear fluid called aqueous humor, which helps maintain the shape of the eye and provides nutrients to the surrounding tissues. The posterior chamber is located behind the iris and in front of the lens, and it plays a crucial role in the overall functioning of the eye.

Submit
152. What structure changes the shape of the lens for far and near vision?

Explanation

The ciliary body is responsible for changing the shape of the lens for far and near vision. This is achieved through the contraction and relaxation of the ciliary muscles, which in turn alters the tension on the suspensory ligaments that hold the lens in place. When the ciliary muscles contract, the tension on the suspensory ligaments decreases, allowing the lens to become more rounded for near vision. Conversely, when the ciliary muscles relax, the tension on the suspensory ligaments increases, causing the lens to flatten for far vision.

Submit
153. The neural tunic

Explanation

The neural tunic refers to the innermost layer of the eye, also known as the retina. It contains ganglion cells, which are responsible for transmitting visual information from the photoreceptor cells to the brain. Additionally, the photoreceptor cells, including rods and cones, are located in the neural tunic and are responsible for detecting light and converting it into electrical signals. Therefore, the correct answer is A and B only.

Submit
154. The human lense focuses light on the photoreceptor cells by

Explanation

The human lens focuses light on the photoreceptor cells by changing shape. This is known as accommodation. When we look at objects that are close to us, the lens becomes thicker and more rounded to increase its refractive power. Conversely, when we look at objects that are far away, the lens becomes thinner and flatter. This ability to change shape allows the lens to adjust the focal length and bring objects into focus on the retina, ensuring clear vision at different distances.

Submit
155.                 is to slow heart rate as                is to fast heart rate

Explanation

Bradycardia refers to a slow heart rate, while tachycardia refers to a fast heart rate. Therefore, the relationship between the two is that bradycardia is to slow heart rate as tachycardia is to fast heart rate.

Submit
View My Results
Cancel
  • All
    All (155)
  • Unanswered
    Unanswered ()
  • Answered
    Answered ()
The shape of the lense is controlled by the
In the human eye most refraction occurs when light passes through the
The ciliary muscle contracts to
There are three different types of cones, each one sensitive to...
An area of the retina that contains only cones and is the site of...
If your vision is 20/15 this means that you can
Which of these is true about the atrial reflex?
An elongae outer segment containing membranous discs and a narrow...
When all three cone populations are stimulated equally, we perceive
Visual pigments are derivatives of the compound
Gravity and linear acceleration are sensed in the
Which of the following would you expect to see in increased numbers in...
The structure that permits blood flow from the right atrium to the...
Which of the following is not one of the six primary taste sensations?
The taste sensation that is triggered by the amino group glutamate is...
The most abundant proteins in blood plasma are
A ray of light entering the eye will encounter these structures in...
The external ear ends at the
A hematocrit provides information on
The auditory ossicles connect the
The vibrations recieved by the tympanic membrane are transferred to...
The middle ear communicates with the nasopharynx through the
The senses of equilibrium and hearing are provided by receptors of the
Excess fluid in...
The structure that overlies the organ of Corti (spiral organ) is the
The structure that supports the spiral organ (of Corti) is the
When an external force bends the stereocilia of the inner ear hair...
A  person with Type A blood has
The enzyme that can digest fibrin and dissolve a clot is
The sensory receptors of the semicircular canals are located in the
All of the following are true of neutrophils, except that they are
Movement of the endolymph in the semicircular canals
Each heme ring in hemoglobin encloses an atom of
Which of these proteins functions to store or transport iron?
The hair cells of the utricle and saccule are clustered in
Some rat poisons contain a toxin that blocks the liver's abilithy...
A person whose platelet count is 40,000/ul is suffering from
Hemolytic disease of the newborn may result if
Perception of gravity and linear acceleration depends on
A moving blood clot is called a(n)
Which of the following is true of eosinophils?
The frequency of a perceived sound depends on 
The combination of plasma and formed elements is called
Each of the following is a characteristic of whole blood except
When a person who lives at sea level vacations in the Rocky Mountains,...
A person who has a low blood volume is said to be
The following is a list of vessels and structures that are associated...
Blood returning to the heart from the pulmonary circuit first enters...
The following is a list of the steps that occur in the production of...
Plasma proteins essential in body defense are the
The  process of lymphopoiesis goes on in all of the following...
Which of the following descriptions best matches the term stereocilia
Which of the following descriptions best matches the term otoliths?
Tetanic muscle contractions don't occur in a normal cardiac muscle...
Plasma is closest in composition to
Granulocytes form in
The coronary sulcus is a groove that
When a rod is stimulated by light
Stroke volume depends on
Plasma composes...
The cusps (leaflets) of atrioventricular valves attach directly to
Which of the following blood count values would be a sign of anemia?
Contractions of the papillary muscles
Which of these descriptions best matches the term T lymphocytes?
During ventricular systole, the
Eileen is a strict vegan and therefore eats no animal products. she...
As a result of the long refractory period in the cardiac action...
The following are structural components of the conducting system of...
                   ...
Pernicious anemia caused by a lack of intrinsic factor is specifically...
The visceral pericardium is the same as the
When a blood clot forms on a ruptured plaque in a coronary artery, the...
Most of the middle layer in the heart wall is composed of
David suffers from a prolapsed mitral valve. This condition would...
Compared to the right ventricle, the left ventricle has all the...
The developmental stage at which erythrocytes enter the circulation is...
The percent fraction of formed elements relative to whole blood is the
An increase in the rate of action potentials from baroreceptors will...
A typical adult hematocrit is
Which of these would cause stroke volume to increase?
Analysis of the electrocardiogram can reveal all of the folliwng,...
Consider these results from a blood lab test. Which value is most...
AV nodal cells are poorly interconnected compared to contractile cells...
The first  blood vessels to branch from the aorta are...
Which of the following descriptions applies/apply to the term myopia?
If a patient's tricuspid valve was leaking during systole, what...
In which of the following cases would the focal distance be greater?
Depolarization of teh atria corresponds to the EKG's
A sudden rise of room brightness would cause
The P wave of the electrocardiogram is a signal from
Which of the following descriptions best matches the term ossicles?
Which of the following is greater during left ventricular systole?
Megan has an infected puncture would to her foot. Which type of white...
If the connection between the vagus nerve and the heart is cut, which...
In adults, the only site of red blood cell production, and the primary...
Cardiac output is increased by
Which of the following descriptions best matches the term aqueous...
The external accoustic meatus ends at
Which of the following would be greater?
If there is a complete block between teh SA node and the AV node, how...
Depolarization of the ventricles is represented on an...
The T wave on an ECG tracing represents
What effect would compressing the inferior vena cava just below the...
Bill wants to determine his blood type, so he takes a few drops of...
Which of the following descriptions best matches the term basilar...
The first heart sound is heard when the
During the isovolumetric phase of ventricular systole, the
An obstruction in blood flow to the kidneys would ultimately result in
During the cardiac cycle, the
The             ...
The volume of blood ejected from each ventricle during a contraction...
The cornea is part of the
Which of the following is not true of monocytes?
Each of the following factors will increase cardiac output, except
The cardioacceleratory center activates sympathetic neurons and the...
"An increase in end-diastolic volume increases the stroke...
Gustatory receptors are sensitive to dissolved chemicals but...
The phase in the cardiac cycle when the mitral valve is closed and the...
Olfactory glands
The mucus that covers the olfactory epithelium does all of the...
All of the following are true of olfactory pathways, except
All of the following are true of the lacrimal glands except that they
Gustatory receptors are located
The palpebrae are connected at the
Olfactory receptors send axons through the cribriform plate. They...
Abnormally slow depolarization of the ventricles would most change the...
People with type AB blood are considered the "universal...
Which of the following is true about rhodopsin?
A pigment synthesized from vitamin A is
During the T wave of the electrocardiogram, the ventricles are
All of the following are true of the fibrous tunic of the eye, except...
Which of the following is true of the vascular tunic of the eye?
People who suffer from hemophilia A fail to produce a functional...
The palpebrae
Pupillary muscle groups are controlled by the ANS. Parasympathetic...
Which of the following statements concerning vision is false?
A structure that is located at the medial canthus and contains glands...
Which of the following procudes a lipid-rich secretion that prevents...
The process of fibrinolysis
The vitreous humor
Pacemaker cells in the SA node
The                  ...
The gelatinous material that gives the eyeball its basic shape is the
Which of these descriptions best matches the term eosinophils?
The transparent portion of the fibrous tunic is the
The first heart sound ("lub")
The part of the eye that determines eye color is the
If the connection between the SA node and AV node becomes blocked
The opening in the iris through which light passes is the
The space between the cornea and the iris is the
The space between the iris and ciliary body and the lens is the
What structure changes the shape of the lens for far and near vision?
The neural tunic
The human lense focuses light on the photoreceptor cells by
               ...
Alert!

Back to Top Back to top
Advertisement