an area of the retina that contains only cones and is the site of sharpest vision is the

an area of the retina that contains only cones and is the site of sharpest vision is the


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Asked by 2 years ago
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Olfactory glandscoat the olfactory epithelium with a pigmented mucus
Olfactory information is first received by which part of the brain?cerebrum
Before an olfactory receptor can detect an odorant, it has tobind to receptors in olfactory cilia
Which of the following is true of olfactory discrimination?The number of olfactory receptors decline as we age.
All of the following are true of olfactory pathways, exceptthey project first to the mamillary bodies and then to the thalamus
Some neural tissues retain stem cells and thus the capacity to divide and replace lost neurons. Which of these special senses can replace its damaged neural receptors?olfaction
A normal, relaxed inhalation carries about ________ of the inhaled air to the olfactory organs2 percent
How would a molecule that mimics cAMP affect an olfactory receptor?A) It would increase sodium permeability. B) It would open chemically-gated sodium channels. C) It would depolarize the olfactory receptor. D) It could trigger an afferent action potential. E) All of the answers are correct. Answer: E
Olfactory receptors send axons through the cribriform plate. They synapse on neurons in theolfactory bulb
Gustatory receptors are locatedon the surface of the tongue.
The function of gustatory receptors parallels that ofolfactory receptors
Which of the following lingual papillae has the largest number of taste buds?circumvallate papillae
Taste buds are monitored by cranial nervesVII, IX, X.
Stimulation of nociceptive receptors within the trigeminal nerve might produce a perception ofpeppery hot
Taste receptors are distributed in which of the following places?A) portions of the larynx B) anterior tip of the tongue C) portions of the pharynx D) surface of the tongue E) All of the answers are correct. Answer: E
An adult has approximately ________ taste buds3,000
All of the following are terms describing the epithelial projections found on the tongue, exceptgustatory papillae.
Taste buds are monitored by which cranial nerve(s)?facial nerve (VII), vagus nerve (X), and glossopharyngeal nerve (IX)
A patient who experienced head trauma has lost the ability to taste spicy food. You should expect damage to cranial nerve ________.V
Which of the following is not one of the six primary taste sensations?peppery
The taste sensation that is triggered by the amino acid glutamate is known asumami
All of the following are true of the lacrimal glands, except that theyproduce a strongly hypertonic fluid.
All of the following are true of the fibrous tunic of the eye, except that itproduces aqueous humor
What structure changes the shape of the lens for far and near vision?ciliary body
Which of the following is true of the vascular tunic of the eye?A) provides a route for blood vessels and lymphatics that supply tissues of the eye B) regulates the amount of light entering the eye C) secretes and reabsorbs the aqueous humor D) controls the shape of the lens E) All of the answers are correct. Answer: E
The palpebraeA) are controlled by cranial nerves. B) contain tarsal glands. C) cover and protect the eye. D) are lined with a palpebral conjunctiva. E) All of the answers are correct. Answer: E
The palpebrae are connected at thelateral and medial canthus
The space between the iris and ciliary body and the lens is theposterior chamber.
The neural tunic of the eyeA) contains ganglion cells. B) contains the photoreceptor cells. C) contains bipolar cells. D) is the deepest layer of the eyeball. E) All of the answers are correct. Answer: E
The human lens focuses light on the photoreceptor cells bychanging shape.
A structure that is located at the medial canthus and contains glands that contribute to a gritty deposit is thelacrimal caruncle.
Which of the following produces a lipid-rich secretion that prevents the upper and lower eyelids from sticking together at their edges?tarsal gland
The vitreous bodyhelps to stabilize the eye and give physical support to the retina.
The space between the cornea and the iris is theanterior chamber.
The shape of the lens is controlled by theciliary muscles.
The ________ covers most of the exposed surface of the eyeconjunctiva
The transparent portion of the fibrous tunic is thecornea
The part of the eye that determines eye color is theiris
The opening in the iris through which light passes is thepupil
In the human eye, most refraction occurs when light passes through thecornea
The ciliary muscle contracts toadjust the shape of the lens for near vision.
Which of the following descriptions best matches the term aqueous humor?excessive production may lead to glaucoma
A sty ________A) is often caused by bacteria. B) is a painful swelling in an eyelash. C) may involve a sebaceous gland. D) may involve a tarsal gland. E) All of the answers are correct. Answer: E
Which of the following is a function of tears?A) lubricate the eye B) wash away debris C) provide oxygen D) nourish the cornea and conjunctiva E) All of the answers are correct. Answer: E
An area of the retina that contains only cones and is the site of sharpest vision is thefovea
Which of the following description applies to the term myopia?nearsightedness
A ray of light entering the eye will encounter these structures in which order?conjunctiva cornea aqueous humor lens vitreous body retina choroid
The cornea is part of thefibrous tunic.
The gelatinous material that gives the eyeball its basic shape is thevitreous humor.
Pupillary muscle groups are controlled by the ANS. Parasympathetic activation causes pupillary ________, and sympathetic activation causes ________.constriction; dilation
If your vision is 20/15, this means that you cansee objects at 20 feet that individuals with normal eyesight can see at 15 feet.
Why must accommodation occur to view objects closer than 20 feet from the eye?The light rays are divergent instead of parallel and require more refraction
During accommodation, the ciliary muscle ________ and the suspensory ligaments become ________ which, in turn, cause the lens to become ________.contracts; loose; round
What structure regulates the amount of light that passes to the photoreceptors of the eye?iris
The optic disc is a blind spot becausethere are no photoreceptors in that area.
During accommodation, the ciliary muscle ________ causing the ciliary body to move ________ and apply ________ tension on the lens.contracts; forward; less
A sudden increase of light into the eye would causecontraction of the sphincter pupillary muscles
When a rod is stimulated by light,A) the plasma membrane becomes hyperpolarized. B) the retinal changes from the 11-cis to the 11-trans form. C) less neurotransmitter is released. D) cGMP decreases and sodium channels close. E) All of the answers are correct. Answer: E
In the light-adapted state,photoreceptors are much less sensitive to stimulation
Under which condition would the release of neurotransmitter by photoreceptors be greatest?in a pitch-black room after 30 minutes
There are three different types of cones, each one sensitive to different light energies. These cones are designatedred, green, blue.
An elongate outer segment containing membranous discs and a narrow connecting stalk that attaches the outer segment to the inner segment describesa photoreceptor.
When all three cone populations are stimulated equally, we perceivewhite
The first step in the process of photoreception isabsorption of a photon by a visual pigment
Visual pigments are derivatives of the compoundrhodopsin
A pigment synthesized from vitamin A isretinal
Which of the following is true about rhodopsin?A) called visual purple B) is bleached during photoreception C) is the visual pigment in rods D) consists of opsin + retinal E) All of the answers are correct. Answer: E
Which of the following statements about the retina is true?A) Ganglion cells send axons to the brain as cranial nerve II. B) Axons carrying its output synapse in the thalamus. C) It has photoreceptors that do not respond to dim light. D) It has photoreceptors that do not respond to red light. E) All of the answers are correct. Answer: E
Having to adjust to a dark room after walking in from bright light is becauserods exposed to strong light need time to regenerate rhodopsin
Where are the visual pigments located in the rods and cones?inside membrane discs stacked in the outer segment
The ________ ear collects sounds waves and transmits them to the ________ ear, which contains auditory ossiclesouter; middle
The external acoustic meatus ends atthe tympanic membrane
Which of these anatomical sequences is correct?tympanum,malleus,incus,stapes,oval window,round window
Which of the following descriptions best matches the term basilar membrane?moves up and down when the stapes moves back and forth
The ________ convey(s) information about head position with respect to gravity.utricle and the saccule
A sound with a frequency of 12,000 hertz wouldbe high-pitched.
A loud noise causesA) a large movement of the tympanic membrane. B) an alerting reaction leading to sympathetic activation. C) reflex contractions of middle ear muscles. D) a big pressure pulse entering the cochlear duct at that oval window. E) All of the answers are correct. Answer: E
Which of the following descriptions best matches the term otoliths?tiny weights necessary for the static sense of equilibrium
The auditory ossicles connect thetympanic membrane to the oval window.
The vibrations received by the tympanic membrane are transferred to the oval window by theauditory ossicles.
The middle ear communicates with the nasopharynx through theauditory tube
The senses of equilibrium and hearing are provided by receptors in theinner ear.
The structure that forms the "roof" of the organ of Corti is thetectorial membrane.
The structure that supports the organ of Corti is thebasilar membrane.
Gravity and linear acceleration are sensed in thesaccule and utricle.
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
The sensory receptors of the semicircular canals are located in theampullae
The region of the ampulla that contains the receptors for rotational (dynamic) equilibrium are calledcristae
The superficial hard part of the inner ear is called the ________ and contains ________ .bony labyrinth; perilymph
Movement of the endolymph in the semicircular canalssignals rotational movements
The structure attached to the oval window that transmits vibrations from the tympanic membrane to the inner ear is thestapes
Low frequency sounds stimulate hair cells on which part of the basilar membrane?the distal end
The energy from a pressure wave in the cochlear fluids is released by the bulging and stretching of theround window
The function of the auditory tube is to:equalize air pressure on both sides of the tympanic membrane
Standing still in an elevator that suddenly lowers will stimulate receptors in theutricle and saccule
An infection that damages the vestibular nerve could result in a loss ofequilibrium
The hair cells of the utricle and saccule are clustered inmaculae
The frequency of a perceived sound depends onwhich part of the cochlear duct is stimulated
Perception of gravity and linear acceleration depends onthe force exerted by otoliths on hair cells of the maculae
Which of the following descriptions best matches the term stapes?seals the oval window
Sound waves are converted into mechanical movements by thetympanic membrane.
The cell bodies of sensory neurons that innervate the hair cells of the cochlea form the ________ ganglionspiral
The vestibular nuclei at the boundary of the pons and the medulla function in all of the following, except that theysend information to the vestibular complex of the inner ear
Which of the following descriptions best matches the term stereocilia?bending these produces receptor potential in hair cells
an area
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Asked: 2 years ago

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