AP 211 Review Exam 1
- 1.
Gustatory receptors are sensitive to dissolved chemicals but insensitive to light. This is due to
- A.
Receptor specificity
- B.
Accessory cells
- C.
Receptor potentials
- D.
The fact that they are interoceptors
- E.
Both B and C
Correct Answer
A. Receptor specificityExplanation
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.Rate this question:
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- 2.
Olfactory glands
- A.
Support the olfactory epithelium
- B.
House the sense of smell
- C.
React to aromatic molecules
- D.
Coat the olfactory epithelium with a pigmented mucus
- E.
Group as olfactory bulbs
Correct Answer
D. Coat the olfactory epithelium with a pigmented mucusExplanation
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.Rate this question:
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- 3.
The mucus that covers the olfactory epithelium does all of the following, except that it
- A.
Keeps the tissue moist
- B.
Dissolves unwanted chemicals and washes them away
- C.
Keeps the tissue free of particles
- D.
Provides a medium to dissolve odorants
- E.
Dilutes potentially dangerous odorants
Correct Answer
B. Dissolves unwanted chemicals and washes them awayExplanation
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.Rate this question:
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- 4.
All of the following are true of olfactory pathways, except
- A.
They exhibit a considerable amount of convergence
- B.
They project first to the mamilllary bodies and then to the thalamus
- C.
They are the only sensory pathways to reach the forebrain without first synapsing in the thalamus
- D.
Primary afferents synapse in the olfactory bulb
Correct Answer
B. They project first to the mamilllary bodies and then to the thalamusExplanation
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.Rate this question:
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- 5.
All of the following are true of the lacrimal glands except that they
- A.
Produce lysozyme
- B.
Produce a strongly hypertonic fluid
- C.
Produce watery, slightly alkaline secretions
- D.
Are located in recesses in the frontal bones
- E.
Produce most of the volume of tears
Correct Answer
B. Produce a strongly hypertonic fluidExplanation
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.Rate this question:
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- 6.
Gustatory receptors are located
- A.
In the ear
- B.
On the surface of the tongue
- C.
On the skin
- D.
In the eye
- E.
In the nose
Correct Answer
B. On the surface of the tongueExplanation
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.Rate this question:
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- 7.
The palpebrae are connected at the
- A.
Chalazion
- B.
Eyelids
- C.
Conjunctiva
- D.
Lateral and medial canthus
- E.
Lacrimal caruncle
Correct Answer
B. EyelidsExplanation
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.Rate this question:
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- 8.
Olfactory receptors send axons through the cribriform plate. They synapse on neurons in the
- A.
Olfactory bulb
- B.
Medial geniculate
- C.
Medulla oblongata
- D.
Cerebral cortex
- E.
Olfactory tract
Correct Answer
A. Olfactory bulbExplanation
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.Rate this question:
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- 9.
Abnormally slow depolarization of the ventricles would most change the shape of the in and ECG tracing.
- A.
R-T interval
- B.
P-R interval
- C.
T wave
- D.
QRS complex
- E.
P wave
Correct Answer
D. QRS complexExplanation
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.Rate this question:
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- 10.
Which of the following is true about rhodopsin?
- A.
Is the visual pigment in rods
- B.
Called visual purple
- C.
Is bleached during photoreception
- D.
Consists of opsin + retinal
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
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.Rate this question:
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- 11.
A pigment synthesized from vitamin A is
- A.
CGMP
- B.
Opsin
- C.
Retinal
- D.
Rhodopsin
- E.
Transducin
Correct Answer
A. CGMPExplanation
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.Rate this question:
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- 12.
All of the following are true of the fibrous tunic of the eye, except that it
- A.
Is where extrinsic eye muscles insert
- B.
Contributes substantial focusing power
- C.
Provides mechanical support and some protection for the eye
- D.
Produces aqueous humor
- E.
Consists of the sclera, limbus, and cornea
Correct Answer
D. Produces aqueous humorExplanation
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.Rate this question:
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- 13.
Which of the following is true of the vascular tunic of the eye?
- A.
Controls the shape of the lens
- B.
Provides a route for blood vessels and lymphatics that supply tissues of the eye
- C.
Regulates the amount of light entering the eye
- D.
Secretes and reabsorbs the aqueous humor
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
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.Rate this question:
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- 14.
The palpebrae
- A.
Cover and protect the eye
- B.
Contain tarsal glands
- C.
Are controlled by cranial nerves
- D.
Support the lateral rectus muscles of the eye
- E.
A, B and C
Correct Answer
E. A, B and CExplanation
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.Rate this question:
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- 15.
Which of the following statements concerning vision is false?
- A.
Fibers of the optic nerve synapse at the lateral geniculates of the thalamus
- B.
Approximately half of the fibers in each optic nerve cross to opposite sides of the brain at the optic chiasm
- C.
The image that is formed on the retina is inverted
- D.
The visual cortex of the brain receives the entire field of vision
- E.
The entire retina receives equal representation in the visual cortex
Correct Answer
E. The entire retina receives equal representation in the visual cortexExplanation
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.Rate this question:
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- 16.
A structure that is located at the medial canthus and contains glands that contribute to a gritty deposit is the
- A.
Lacrimal caruncle
- B.
Conjunctiva
- C.
Chalazion
- D.
Meibomian gland
- E.
Palpebra
Correct Answer
A. Lacrimal caruncleExplanation
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.Rate this question:
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- 17.
Which of the following procudes a lipid-rich secretion that prevents the upper and lower eyelids from sticking together at their edges?
- A.
Palpebra
- B.
Lacrimal caruncle
- C.
Conjuntiva
- D.
Chalazion
- E.
Tarsal gland
Correct Answer
E. Tarsal glandExplanation
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.Rate this question:
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- 18.
The vitreous humor
- A.
Is replaced at the rate of 20 percent per year until middle age
- B.
Fills the posterior cavity
- C.
Helps to stabilize the eye and give physical support to the retina
- D.
A, B and C
- E.
B and C only
Correct Answer
C. Helps to stabilize the eye and give pHysical support to the retinaExplanation
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.Rate this question:
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- 19.
The covers most of the exposed surface of the eye
- A.
Conjunctiva
- B.
Canthus
- C.
Iris
- D.
Anterior chamber
- E.
Cornea
Correct Answer
A. ConjunctivaExplanation
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.Rate this question:
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- 20.
The transparent portion of the fibrous tunic is the
- A.
Conjunctiva
- B.
Canthus
- C.
Cornea
- D.
Iris
- E.
Pupil
Correct Answer
D. IrisExplanation
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.Rate this question:
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- 21.
The part of the eye that determines eye color is the
- A.
Iris
- B.
Canal of Schlemm
- C.
Pupil
- D.
Cornea
- E.
Conjunctiva
Correct Answer
C. PupilExplanation
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.Rate this question:
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- 22.
The opening in the iris through which light passes is the
- A.
Anterior chamber
- B.
Cornea
- C.
Conjunctiva
- D.
Posterior chamber
- E.
Pupil
Correct Answer
E. PupilExplanation
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.Rate this question:
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- 23.
The space between the cornea and the iris is the
- A.
Posterior cavity
- B.
Aqueous humor
- C.
Vitreous segment
- D.
Anterior segment or chamber
- E.
Pupil
Correct Answer
D. Anterior segment or chamberExplanation
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.Rate this question:
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- 24.
The space between the iris and ciliary body and the lens is the
- A.
Pupil
- B.
Aqueous segment
- C.
Posterior chamber or segment
- D.
Vitreous humor
- E.
Anterior cavity
Correct Answer
C. Posterior chamber or segmentExplanation
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.Rate this question:
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- 25.
What structure changes the shape of the lens for far and near vision?
- A.
Extrinsic eye muscle
- B.
Aqueous humor
- C.
Iris
- D.
Ciliary body
- E.
None, because the lens is rigid
Correct Answer
D. Ciliary bodyExplanation
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.Rate this question:
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- 26.
The neural tunic
- A.
Contains ganglion cells
- B.
Contains the photoreceptor cells
- C.
Produces the vitreous humor
- D.
A, B and C
- E.
A and B only
Correct Answer
E. A and B onlyExplanation
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.Rate this question:
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- 27.
The human lense focuses light on the photoreceptor cells by
- A.
Opening and closing
- B.
Changing shape
- C.
Moving in and out
- D.
Moving up and down
- E.
Dilating and constricting
Correct Answer
B. Changing shapeExplanation
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.Rate this question:
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- 28.
The shape of the lense is controlled by the
- A.
Pupillary sphincter muscles
- B.
Pupillary radial muscles
- C.
Ciliary muscles
- D.
Iris
- E.
A, B and C
Correct Answer
C. Ciliary musclesExplanation
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.Rate this question:
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- 29.
In the human eye most refraction occurs when light passes through the
- A.
Cornea
- B.
Vitreous humor
- C.
Aqueous humor
- D.
Iris
- E.
Lens
Correct Answer
A. CorneaExplanation
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.Rate this question:
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- 30.
The ciliary muscle contracts to
- A.
Adjust the shape of the cornea and vitreous
- B.
Control the amount of light reaching the retina
- C.
Adjust the shape of the lens for distant vision
- D.
Control the production of aqueous humor
- E.
Adjust the shape of the lens for near vision
Correct Answer
E. Adjust the shape of the lens for near visionExplanation
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.Rate this question:
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- 31.
There are three different types of cones, each one sensitive to different light energies. These cones are designated
- A.
Yellow, red, blue
- B.
Red, green, blue
- C.
Red, white, blue
- D.
Red, yellow, blue
- E.
Red, green, yellow
Correct Answer
B. Red, green, blueExplanation
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.Rate this question:
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- 32.
An area of the retina that contains only cones and is the site of sharpest vision is the
- A.
Inner segment
- B.
Tapetum lucidum
- C.
Fovea
- D.
Optic disc
- E.
Outer segment
Correct Answer
C. FoveaExplanation
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.Rate this question:
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- 33.
An elongae outer segment containing membranous discs and a narrow connecting stalk that attaches the outer segment to the inner segment describes
- A.
Photoreceptor
- B.
A ganglion cell
- C.
A bipolar cell
- D.
A horizontal cell
- E.
A amacrine cell
Correct Answer
A. pHotoreceptorExplanation
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.Rate this question:
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- 34.
When all three cone populations are stimulated equally, we perceive
- A.
Blue
- B.
Blackness
- C.
Green
- D.
Red
- E.
White
Correct Answer
E. WhiteExplanation
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.Rate this question:
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- 35.
Visual pigments are derivatives of the compound
- A.
Rhodopsin
- B.
Transducin
- C.
Opsin
- D.
CGMP
- E.
Retinal
Correct Answer
A. RhodopsinExplanation
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.Rate this question:
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- 36.
Gravity and linear acceleration are sensed in the
- A.
Organ of Corti
- B.
Semicircular canals
- C.
Cochlea
- D.
Statoconia
- E.
Saccule and utricle
Correct Answer
E. Saccule and utricleExplanation
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.Rate this question:
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- 37.
Which of the following is not one of the six primary taste sensations?
- A.
Peppery
- B.
Umami
- C.
Sweet
- D.
Salty
- E.
Sour
Correct Answer
A. PepperyExplanation
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.Rate this question:
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- 38.
The taste sensation that is triggered by the amino group glutamate is known as
- A.
Our
- B.
Sweet
- C.
Umami
- D.
Salty
- E.
Peppery
Correct Answer
C. UmamiExplanation
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.Rate this question:
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- 39.
The most abundant proteins in blood plasma are
- A.
Globulins
- B.
Albumins
- C.
Lipoproteins
- D.
Transport proteins
- E.
Fibrinogens
Correct Answer
B. AlbuminsExplanation
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.Rate this question:
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- 40.
A ray of light entering the eye will encounter these structures in which order?
- A.
Vitreous body-retina-choroid-aqueous humor-lens-conjunctiva-cornea
- B.
Cornea-aqueous humor-vitreous body-lens-conjunctiva-choroid-retina
- C.
Conjunctiva-cornea-aqueous humor-lens-vitreous body-retina-choroid
- D.
Cornea-aqueous humor-conjunctiva-lens-vitreous humor-retina-choroid
- E.
Conjunctiva-cornea-lens-aqueous humor-vitreous body-retina-choroid
Correct Answer
C. Conjunctiva-cornea-aqueous humor-lens-vitreous body-retina-choroidExplanation
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.Rate this question:
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- 41.
The external ear ends at the
- A.
Cochlea
- B.
Ossicles
- C.
Pinna
- D.
Vestibule
- E.
Tympanic membrane
Correct Answer
E. Tympanic membraneExplanation
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.Rate this question:
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- 42.
The auditory ossicles connect the
- A.
Tympanic membrane to the round window
- B.
Oval window to the round window
- C.
Stapedius to the tympanic membrane
- D.
Tympanic membrane to the oval window
- E.
Otitis to the media
Correct Answer
D. Tympanic membrane to the oval windowExplanation
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.Rate this question:
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- 43.
The vibrations recieved by the tympanic membrane are transferred to the oval window by the
- A.
Oval window
- B.
Stapedius muscle
- C.
Tensor tympani
- D.
Cochlea
- E.
Auditory ossicles
Correct Answer
E. Auditory ossiclesExplanation
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.Rate this question:
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- 44.
The middle ear communicates with the nasopharynx through the
- A.
Membranous labyrinth
- B.
Bony labyrinth
- C.
Auditory meatus
- D.
Auditory tube
- E.
Auricle
Correct Answer
D. Auditory tubeExplanation
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.Rate this question:
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- 45.
The senses of equilibrium and hearing are provided by receptors of the
- A.
Perilymph
- B.
Membranous endolymph
- C.
Inner ear
- D.
Bony labyrinth
- E.
Organ of Schlemm
Correct Answer
C. Inner earExplanation
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.Rate this question:
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- 46.
The structure that overlies the organ of Corti (spiral organ) is the
- A.
Endolymph
- B.
Stapedius
- C.
Perilymph
- D.
Tectorial membrane
- E.
Basilar membrane
Correct Answer
D. Tectorial membraneExplanation
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.Rate this question:
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- 47.
The structure that supports the spiral organ (of Corti) is the
- A.
Tectorial membrane
- B.
Vestibular duct
- C.
Basilar membrane
- D.
Tympanic membrane
- E.
Membranous labyrinth
Correct Answer
C. Basilar membraneExplanation
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.Rate this question:
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- 48.
When an external force bends the stereocilia of the inner ear hair cells
- A.
Dizziness results
- B.
There is a change in the transmembrane potential of the hair cells
- C.
The hair cells are temporarily damaged
- D.
The cells become unresponsive
- E.
The force is converted into mechanical energy
Correct Answer
B. There is a change in the transmembrane potential of the hair cellsExplanation
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.Rate this question:
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- 49.
The sensory receptors of the semicircular canals are located in the
- A.
Perilymph
- B.
Ampullae
- C.
Cupulas
- D.
Utricles
- E.
Saccules
Correct Answer
B. AmpullaeExplanation
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.Rate this question:
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- 50.
Movement of the endolymph in the semicircular canals
- A.
Signals linear acceleration
- B.
Allows us to hear low tones
- C.
Signals body position with respect to gravity
- D.
Produces a rushing sound
- E.
Signals rotational movements
Correct Answer
E. Signals rotational movementsExplanation
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.Rate this question:
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Mar 21, 2023Quiz Edited by
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Feb 11, 2013Quiz Created by
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