Exam #1- Special Senses, Blood, & Heart

The cochlea is the correct answer because it is the main receptor site for hearing in the inner ear. It is a spiral-shaped, fluid-filled structure that contains tiny hair cells. When sound waves enter the ear, they cause vibrations in the fluid of the cochlea, which in turn stimulate the hair cells. These hair cells then convert the vibrations into electrical signals that are sent to the brain, allowing us to perceive and interpret sound. The other options mentioned, such as the cristae ampullaris, oval window, and semicircular canals, are all important structures in the inner ear, but they are primarily involved in balance and equilibrium, not hearing.

Erythrocytes, or red blood cells, are responsible for transporting oxygen throughout the body. They contain hemoglobin, a protein that binds to oxygen. They have a unique biconcave disk shape, which allows for increased surface area and efficient oxygen exchange. However, erythrocytes do not have a large nucleus. In fact, they have no nucleus at all, as it is expelled during their development to make more room for hemoglobin.

The intrinsic muscles of the ciliary body play a crucial role in regulating the shape of the lens. These muscles control the tension in the suspensory ligaments that attach to the lens, allowing the lens to change its shape and adjust its focal length. By contracting or relaxing, the ciliary muscles can make the lens thicker or thinner, enabling the eye to focus on objects at different distances. This mechanism is known as accommodation and is essential for clear vision at varying distances.

A stationary blood clot is called a thrombus. This is a solid mass formed by the coagulation of blood within a blood vessel. Thrombi can obstruct blood flow and cause various complications depending on their location. Unlike an embolus, which is a clot that travels through the bloodstream, a thrombus remains in place. A tumor is an abnormal growth of cells, and a phagocyte is a type of white blood cell that engulfs and destroys foreign particles.

Hemocytoblasts are a type of stem cells that have the ability to differentiate into various types of blood cells. They are responsible for producing all the formed elements of blood, including red blood cells, white blood cells, and platelets. This means that hemocytoblasts can give rise to erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). Therefore, the correct answer is that hemocytoblasts produce all formed elements of blood.

Erythropoietin is the hormone that regulates the production of red blood cells (RBCs). It is produced by the kidneys in response to low oxygen levels in the body. Erythropoietin stimulates the bone marrow to produce more red blood cells, which helps in increasing the oxygen-carrying capacity of the blood. This hormone plays a crucial role in maintaining the balance of RBCs in the body and ensuring adequate oxygen supply to tissues and organs.

Whole blood refers to the combination of plasma and formed elements. Plasma is the liquid component of blood that contains various proteins, hormones, and nutrients, while formed elements include red blood cells, white blood cells, and platelets. Together, these components make up whole blood, which is responsible for transporting oxygen, nutrients, hormones, and waste products throughout the body. Serum, packed cell volume, lymph, and interstitial fluid are not the correct answers as they do not encompass both plasma and formed elements.

Monocytes are a type of white blood cell that are produced in the bone marrow and then circulate in the bloodstream. They are considered a part of the immune system and play a role in defending the body against pathogens. Macrophages are derived from monocytes, as monocytes migrate from the bloodstream into tissues and mature into macrophages. Macrophages are larger cells that have a wide range of functions, including phagocytosis (engulfing and destroying pathogens), antigen presentation, and cytokine production. Therefore, the correct answer is monocytes.

The correct answer is "a and c only" because both the green cone and red cone are types of color photoreceptors. The green cone is responsible for detecting green light, while the red cone detects red light. The yellow cone is not a type of color photoreceptor, so it is not included in the correct answer.

The anterior segment of the eye contains the aqueous humor. The aqueous humor is a clear, watery fluid that fills the front portion of the eye, including the anterior chamber. It helps maintain the shape of the eye, provides nutrients to the cornea and lens, and helps remove waste products. The posterior segment of the eye, on the other hand, contains the vitreous humor, a gel-like substance that fills the back portion of the eye.

The baroreceptor reflexes are responsible for maintaining blood pressure within a normal range. When there is an increase in blood pressure, the baroreceptors detect this change and send signals to the brain. In response, the brain initiates a series of physiological processes to decrease heart rate and stroke volume. This helps to reduce the blood pressure back to a normal level. Therefore, an increase in blood pressure triggers the baroreceptor reflexes to decrease heart rate and stroke volume.

The specific valve located between the left atrium and left ventricle is the mitral valve. It is also known as the bicuspid valve because it consists of two cusps or flaps. Therefore, the correct answer is "a and c only" as both "mitral valve" and "bicuspid valve" refer to the same valve.

A hemoglobin molecule is composed of 4 protein chains and 4 heme groups. Hemoglobin is a complex protein found in red blood cells that is responsible for carrying oxygen throughout the body. Each hemoglobin molecule consists of four protein chains, two alpha chains, and two beta chains. Each protein chain is associated with a heme group, which contains an iron atom that binds to oxygen. Therefore, a hemoglobin molecule has a total of four protein chains and four heme groups.

The correct answer is none of the above because the agranulocytes do not include eosinophils, basophils, or neutrophils. Agranulocytes are a type of white blood cell that lack visible granules in their cytoplasm. The agranulocytes include lymphocytes and monocytes.

During the contraction phase of the cardiac cycle, the heart muscles contract to pump blood out of the heart and into the arteries. This phase is known as systole. It is responsible for the forceful ejection of blood from the ventricles to the rest of the body. Diastole, on the other hand, refers to the relaxation phase of the cardiac cycle when the heart muscles relax and fill with blood. Bradycardia and tachycardia are abnormal heart rhythms characterized by a slow or fast heart rate, respectively. Ejection is a general term that refers to the process of expelling or forcing something out.

The second heart sound (S2) occurs during the closing of the semilunar valves. These valves, namely the aortic and pulmonary valves, are located between the ventricles and the major arteries leaving the heart. When the ventricles finish contracting and begin to relax, the pressure inside the ventricles decreases. This causes the semilunar valves to close, preventing blood from flowing back into the ventricles. The closure of these valves produces the second heart sound, indicating the completion of the ventricular contraction phase and the beginning of the relaxation phase.

The equation "heart rate times stroke volume equals cardiac output" is a fundamental principle in cardiovascular physiology. Cardiac output refers to the amount of blood pumped by the heart in one minute, and it is calculated by multiplying the heart rate (the number of heartbeats per minute) by the stroke volume (the volume of blood pumped out of the heart with each beat). This equation demonstrates that increasing either the heart rate or the stroke volume will result in an increased cardiac output, which is an important measure of the heart's efficiency in delivering oxygen and nutrients to the body's tissues.

The atrium is a chamber in the heart that receives blood from the veins. Its main function is to collect blood and then pump it into the ventricles, which will further pump the blood to the lungs or the rest of the body. Therefore, the correct answer is "collect blood".

The first step in homeostasis is vascular spasm. Homeostasis refers to the body's ability to maintain a stable internal environment. When there is an injury or damage to blood vessels, the body initiates a series of responses to stop bleeding and restore normal conditions. Vascular spasm is the immediate constriction of blood vessels in response to injury, which helps reduce blood flow and prevent further bleeding. This vasoconstriction is followed by other steps like platelet plug formation, coagulation, and fibrinolysis to fully restore homeostasis.

The sinoatrial (SA) node is often referred to as the pacemaker of the heart because it is responsible for initiating the electrical impulses that regulate the heart's rhythm. Located in the right atrium, the SA node generates electrical signals that cause the atria to contract and pump blood into the ventricles. These signals then travel through the atrioventricular (AV) node, bundle of His, and Purkinje fibers to coordinate the contraction of the ventricles. The AV valve and fossa ovalis are structures within the heart, but they do not have a role in generating electrical impulses or regulating the heart's rhythm.

Thrombin is the enzyme that catalyzes the reaction of fibrinogen to fibrin. Thrombin is a key enzyme in the blood clotting process and is responsible for converting soluble fibrinogen into insoluble fibrin, which forms the meshwork of a blood clot. This conversion is crucial for the formation and stabilization of blood clots, helping to prevent excessive bleeding. Amylase is an enzyme that breaks down carbohydrates, while erythropoietin is a hormone that stimulates the production of red blood cells. Prothrombin and prothrombinase are involved in the blood clotting process but are not directly responsible for the conversion of fibrinogen to fibrin.

The special senses refer to the senses that are more complex and specialized than the general senses. They include vision, taste, smell, balance, and touch. However, touch is not considered a special sense as it is a general sense that is not confined to specific sensory organs like the others. Touch can be felt throughout the body and is not limited to specific receptors or organs.

The glossopharyngeal nerve (CN#9) innervates the posterior 1/3 of the tongue. This nerve is responsible for carrying sensory information from the tongue, as well as controlling the muscles involved in swallowing and salivation. The olfactory nerve (CN#1) is responsible for the sense of smell, the vagus nerve (CN#10) controls various organs in the body, and the vestibulocochlear nerve (CN#8) is responsible for hearing and balance. Therefore, the glossopharyngeal nerve is the correct answer for innervating the posterior 1/3 of the tongue.

The iris is the correct answer because it contains muscles that control the size of the pupil, which in turn regulates the amount of light entering the eye. The muscles in the iris contract or relax to adjust the size of the pupil, allowing more or less light to pass through. This mechanism helps to protect the eye from excessive light and maintain optimal vision in different lighting conditions.

The autonomic centers for cardiac function are located in the medulla oblongata. This part of the brainstem plays a crucial role in regulating the cardiovascular system. It controls the heart rate, blood pressure, and the coordination of cardiac muscle contractions. The medulla oblongata receives input from various sensors in the body and sends signals to the heart through the autonomic nervous system to maintain proper cardiac function. The cerebral cortex is responsible for higher brain functions and does not directly control cardiac activity. The right atrium and left ventricle are chambers of the heart and do not house the autonomic centers for cardiac function. The pons, another part of the brainstem, is involved in regulating respiration but not specifically cardiac function.

The stroke volume refers to the amount of blood that is ejected from the ventricle during a contraction. This means that with each heartbeat, a certain volume of blood is pumped out of the ventricle and into the circulatory system. The other options in the question are not correct because they do not accurately describe the concept of stroke volume.

The pulmonary trunk is the correct answer because it is the vessel that exits the right ventricle and carries deoxygenated blood to the pulmonary circuit. The pulmonary veins carry oxygenated blood from the lungs to the left atrium, the pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs, and the inferior vena cava carries deoxygenated blood from the lower body to the right atrium. Therefore, none of the other options exit the right ventricle carrying blood to the pulmonary circuit.

The semicircular canals are responsible for detecting rotational movement of the head. They are part of the vestibular system, which helps maintain balance and spatial orientation. The canals are filled with fluid and lined with tiny hair cells that detect the movement of the fluid as the head rotates. This information is then sent to the brain, allowing us to perceive and adjust to changes in our head position. The other options, static equilibrium and linear acceleration, are functions of other structures within the vestibular system, such as the utricle and saccule. Therefore, the correct answer is "rotational movement of the head."

The stapes is the auditory ossicle that covers the oval window. The oval window is a membrane located in the inner ear that separates the middle ear from the cochlea. When sound waves enter the ear, they cause vibrations in the eardrum, which in turn transmit these vibrations to the ossicles. The stapes, being the smallest bone in the human body, acts as a piston and transfers these vibrations to the oval window, allowing sound to be transmitted into the fluid-filled cochlea for further processing.

When hemoglobin is broken down, the heme component of the molecule is responsible for the formation of bilirubin. Heme contains iron (Fe2+) which is released during the breakdown process and is converted into bilirubin. Bilirubin is a yellow pigment that is further processed by the liver and excreted in bile. The globin chains, on the other hand, are responsible for the protein structure of hemoglobin and do not directly contribute to bilirubin formation. Therefore, the correct answer is heme.

Collagen is not a plasma protein. Plasma proteins are proteins found in the blood plasma, and they play various roles including transportation, immune response, and blood clotting. Fibrinogen, albumin, and globulin are all examples of plasma proteins. However, collagen is a structural protein found in connective tissues such as skin, tendons, and bones, and it is not present in the plasma.

Neutrophils are the most numerous leukocytes in the blood. They play a crucial role in the immune system by quickly migrating to sites of infection or inflammation. Neutrophils are phagocytic cells, meaning they can engulf and destroy pathogens. They are the first responders to an infection and are highly effective in fighting bacterial infections. Their abundance in the bloodstream allows for a rapid immune response when needed.

B cells are a type of leukocyte that produces antibodies. Antibodies are proteins that are essential for the immune system's ability to recognize and neutralize foreign substances such as bacteria and viruses. B cells are responsible for the production of specific antibodies that can bind to and target these foreign substances, marking them for destruction by other immune cells. This process is crucial for the body's defense against infections and plays a vital role in adaptive immunity.

Megakaryocytes are the cells in the red bone marrow that produce platelets. These large cells undergo a process called thrombopoiesis, where they fragment into small pieces called platelets. Platelets are crucial for blood clotting and help in preventing excessive bleeding. Reticulocytes are immature red blood cells, monocytes are a type of white blood cell, lymphocytes are also a type of white blood cell, and erythrocytes are mature red blood cells. Therefore, none of these cells produce platelets.

The pitch of a sound is determined by the frequency of the sound waves. Frequency refers to the number of cycles or vibrations that occur in a given time period. Higher frequency sound waves have a higher pitch, while lower frequency sound waves have a lower pitch. Intensity refers to the amount of energy carried by the sound waves, and amplitude refers to the maximum displacement of the sound waves. While intensity and amplitude can affect the volume or loudness of a sound, they do not determine the pitch. Therefore, the correct answer is the frequency of sound waves.

Globulin is a plasma protein that is used in antibody production. Antibodies, also known as immunoglobulins, are proteins produced by the immune system in response to the presence of foreign substances, such as pathogens. These antibodies help in neutralizing and eliminating the foreign substances from the body. Globulins, along with other plasma proteins, play a crucial role in the production and functioning of antibodies. Therefore, globulin is the correct answer for this question.

through the coronary sinus!

The correct answer is "a and c only" because both the visceral pericardium and epicardium refer to the outer layer of the heart. The visceral pericardium is the inner layer of the pericardium that directly covers the heart, while the epicardium is the outermost layer of the heart wall. The parietal pericardium, on the other hand, is the outer layer of the pericardium but not the outer layer of the heart itself.

The intensity or amplitude of sound waves determines the loudness. Loudness refers to the perceived volume or strength of a sound. It is directly related to the amplitude of the sound waves, with higher amplitudes resulting in louder sounds. Therefore, the correct answer is loudness.

The coronary arteries supply blood to the heart. These arteries branch off from the aorta and deliver oxygenated blood to the heart muscle. The coronary sinus and cardiac veins are not responsible for supplying blood to the heart, but rather for draining deoxygenated blood from the heart. Therefore, the correct answer is "coronary arteries."

The end diastolic volume (EDV) refers to the amount of blood in the ventricles when they start to contract. This volume represents the maximum amount of blood that the ventricles can hold before contraction. It is an important measure of cardiac function as it indicates the preload or the amount of stretch on the ventricular walls, which influences the force of contraction and the amount of blood ejected during systole.

Frank-Starling's Law/Principle of cardiac function states that an increased stretch of the ventricles produces a greater force of contraction. This means that when the ventricles are filled with more blood (preload), they will generate a stronger contraction, resulting in more blood being pumped out of the heart. Therefore, the correct answer is "all of the above" as it encompasses the concepts of increased stretch, more blood in generating more blood out, and preload.

The first heart sound (S1) results from the closing of the atrioventricular valves. These valves, namely the tricuspid valve and the mitral valve, separate the atria from the ventricles. When the ventricles contract during systole, the pressure inside the ventricles increases, causing the atrioventricular valves to close. This closure produces the first heart sound, known as S1. The opening of semilunar valves and the opening of atrioventricular valves occur during different phases of the cardiac cycle and do not contribute to the first heart sound.

Afterload refers to the resistance that the heart must overcome in order to eject blood from the ventricles into the systemic circulation. It is determined by factors such as arterial pressure and vascular resistance. An increased afterload requires the heart to generate more tension in order to open the semilunar valves and eject blood effectively. Therefore, the amount of tension that the heart must produce to open the semilunar valves to eject blood defines afterload.

An increase in eosinophils in a differential white blood cell count test is typically seen in situations such as allergic reactions and parasitic infections. Eosinophils are a type of white blood cell that are involved in the immune response against parasites and play a role in allergic reactions. Therefore, it is expected to see an increase in eosinophils in the presence of both allergic reactions and parasitic infections. Acute bacterial infections, on the other hand, typically do not cause a significant increase in eosinophils.

During the plateau phase of the cardiac action potential, the opening of Ca2+ channels is responsible. This influx of Ca2+ ions into the cardiac cells prolongs the depolarization phase and helps to sustain the contraction of the heart muscle. This phase is crucial for proper pumping of blood as it allows for sufficient time for the heart to empty its chambers. The opening of Ca2+ channels also triggers the release of more Ca2+ ions from the sarcoplasmic reticulum, further enhancing the contraction of the heart.

Acetylcholine release at the pacemaker of the heart leads to a decrease in heart rate. Acetylcholine is a neurotransmitter that slows down the electrical impulses in the heart, resulting in a decrease in heart rate. This is in contrast to sympathetic stimulation of the heart, which would increase heart rate, and norepinephrine release at the pacemaker of the heart, which would also increase heart rate. Therefore, the correct answer is acetylcholine release at the pacemaker of the heart.

The T wave on an EKG represents ventricular repolarization. After the ventricles contract (ventricular depolarization), they need to reset and prepare for the next contraction. This resetting process is called repolarization, and it is represented by the T wave on the EKG. Therefore, the correct answer is ventricular repolarization.