What are tears and what structure secretes them?
Tears are a dilute saline secretion that contains mucus, antibodies, and lysozyme. They are secreted by the lacrimal glands
What is the blind spot and why is it blind?
The blind spot of the eye is the optic disc. It is the part of the retina where the optic nerve exits the eye and it is "blind" because it is a region of the retina that lacks photoreceptors
Sam's opteometrist tells him that his intraocular pressure is high. What is this condition called and which fluid does it involve?
An increase in intraocular pressure is called glaucoma and is due to an accumulation of aqueous humor, usually because of impaired drainage of the fluid
Arrange the following in the order that light passes through them to reach the photoreceptors in the retina: lens, bipolar cells, vitreous humor, cornea, aqueous humor, ganglion cells
Light passes through the cornea, aqueous humor, lens, vitreous humor, ganglion cells and bipolar cells before it reaches the photoreceptors
You have been reading this book for a while now and your eyes are beginning to tire. Which intrinsic eye muscles are relaxing as you stare thoughtfully into the distance?
the ciliary muscles and sphincter pupillae relax for distant vision.
Why does your near point of vision move farther away as you age?
the near point moves farther away as you age because the lens becomes less flexible, so that it is unable to assume the more rounded shape required for near vision.
For each of the following, indicate whether it applies to rods or coneS: vision in bright light; only one type of visual pigment; most abundant in the periphery of the retina; many feed into one ganglion cell; color vision; higher sensitvity; higher acuity.
the following are characteristics of cones: "vision in bright light," "color vision," and "higher acuity." The following are characteristics of rods: "only one type of visual pigment," "most abundant in the periphery of the retina," "many feed into one ganglion cell," and "higher sensitivity."
What does bleaching of the pigment mean and when does it happen?
breakdown of the retinal-opsin combination is called bleaching of the pigment. It occurs with exposure combination is called bleaching of the pigment. It occurs with exposure to light.
What part of the visual field would be affected by a tumor in the right visual cortex? By a tumor compressing the right optic nerve?
a tumor in the right visual cortex would affect the left visual field. A tumor compressing the right optic nerve would affect both the left and right visual fields from the right eye only.
Name the five taste modalities. Name ht three types of papillae that have taste buds.
the five taste modalities are sweet, sour, bitter, salty, and umami. The fungiform, circumvallate, and foliate papillae contain taste buds.
Olfactory receptor cells have cilia and taste cells have hairs. How do these structures help the cells perform their functions?
the cilia and hairs of these receptor cells greatly increase the surface area of sensory receptors.
Apart from the bony boundaries, what structure separates the external from the middle ear? What two (nonbone) structures separate the middle from the inner ear?
the tympanic membrane separates the external from the middle ear. The oval and round windows separate the middle from the inner ear.
What structure inside the spiral organ allows us to differentiate sounds of different pitch?
the basilar membrane allows us to differentiate sounds of different pitch.
If the brain stem did not receive input from both ears, what would you not be able to do?
You would not be able to locate the origin of a sound if the brain stem did not receive input from both ears
Six year old Mohammed has a cold and says his ears feel "full" and he "can't hear well." Explain what has happened in Mohammed's ears. Which type of deafness does Mohammed have - conduction or sensorineural?
the fullness in Mohammed's ears is likely due to an accumulation of fluid in the middle ear as a result of his upper respiratory infection spreading into his ear. He has a form of conduction deafness.
For each of the following statements, indicate whether it applies to a macula or a crista ampullaris: insidea semicircular canal; contains otoliths; responds to linear acceleration and deceleration; has a cupula; responds to rotational acceleration and deceleration; inside a saccule.
the following apply to a macula: "contain otholiths," "responds to linear acceleration or deceleration," and "insde a saccule." The following apply to a crista ampullaris: "inside a semicircular canal," "has a capula," "responds to rotational accelearation and deceleration."
What age-related changes make it more difficult for the elderly to see at night?
With age, the lends discolors and loses its clarity and the dilator pupillae muscles become less efficient, decreasing the amount of light that reaches the retinas at night
Which sequence best describes a normal route for the flow of tears from the eyes into the nasal cavity?
lacrimal canaliculi, nasolacrimal ducts, nasal cavity
The phenomenon of dark adaptation is best explained by the fact that
rods exposed to intense light need time to regenerate rhodopsin
Which sequence of reactions occurs when a person looks at a distant object?
pupils dilate, ciliary zonule becomes taut, lenses become less convex
During embryonic development, the lens of the eye forms
from the surface ectoderm overlying the optic cup
sensory impulses transmitted over the facial, glossopharyngeal, and vagus nerve are involved in the sensation of
cells in the olfactory bulb that act as local "integrators" of olfactory inputs are the
conduction of sound from the middle ear to the internal ear occurs via vibration of the
stapes in the oval window
the structure that allows pressure in the middle ear to be equalized with atmospheric pressure is the
which of the following is important in maintaing the balance of the body
visual cues, semicircular canals, the saccule, proprioceptors
static equilirium receptors that repotrt the position of the ehad in space relative to the pill of gravity are