chapter 17 - special senses Flashcards
what is the process of perceiving smells?
olfaction
what are smell receptors?
chemoreceptors
what nerve is the anterior 2/3 of the tongue?
facial nerve
which nerve serves taste buds in the posterior 1/3 of the tongue?
glassopharyngeal
which nerve serves test buds in the throat and epiglottis?
vagus nerve
what are specialized cells that begin the process of converting light rays into nerve impulses?
photoreceptors
what are the two parts of the retina?
rods and cones
in the retina, what detects color?
cones
in the retina, what is better for bright light?
cones
in the retina, what detects black and white?
rods
in the retina, what is better for dim light?
rods
what is normal vision?
emmetropic
what is the fibrous tunic composed of?
the cornea and the sclera
what does the cornea do?
helps focus light onto the retina
what is the vascular tunic composed of?
choroid and ciliary body
what does the iris do?
regulates the amount of light entering the eyeball through the pupil
what are the two muscles that make up the iris?
the radial muscle and the circular muscle
what does the radial muscle do?
makes pupils open larger (“radiates” away)
what type of response occurs in low light?
sympathetic response (circular muscle)
what type of response occurs in bright light?
parasympathetic response (radial muscle)
what is another name for a blind spot?
optic disc
what part of the eye is similar to a lens of a camera?
the cornea (focuses image)
what part of the eye is similar to film?
retina
what is bending of light?
refraction
what is the change in shape of lens to focus on close objects?
accommodation
what is the inward movement of the eye?
convergence
what is it called when only close objects can be seen clearly?
myopia
what is hyperopia?
farsightedness
what is it called when only distant objects can be seen clearly?
hyperopia
what is the loss of vision due to aging called?
presbyopia
what are the three auditory ossicles?
the malleus (hammer), incus (anvil), and stapes (stirrup)
what are the muscles of the middle ear?
the stapedius and the tensor tympani
what is the smallest skeletal muscle?
the stapedius
what does the middle ear do?
uses bony system to amplify sound vibrations
what does the inner ear do?
contains hair cells that are receptors for hearing and balance
where does hearing and balance take place?
inner ear
what are the three areas of the bony labyrinth?
the semicircular canals, the vestibule, and the cochlea
what is the vestibule used for?
static equilibrium
what is the semicircular canal control?
dynamic equilibrium
what is the portion responsible for the sensation of hearing?
the cochlea
