Special Senses, Vision and Hearing Flashcards
What is olfaction?
smell
What is audition
hearing
What is gustation
taste
1) Eye/Vision: CN-II; sensitive to photons
- part of the CNS
- enables sight, but also allows light to set body clock
- voluntary and reflex
2) Ear/equilibrium and hearing- CN-VIII
- Sensitive to sound waves; movement and gravity
- All through the movement of hair cells
CN-II involves what
optic
CN-VIII involves what
vestibulocochlear
What is the cornea
The transparent portion of the fibrous layer of the anterior surface of the eye
What is the lateral canthus
Where the 2 eyelids meet lateral
What is the pupil
central opening in eye
What is the medial canthus
where 2 eyelids meet medial
What does the lacrimal apparatus do
produces and removes tears
lubricate, removes debris, provide nutrients and O_2 to the cornea and conjunctiva
What is the function of the sclera/cornea?
outer—fibrous, supports, protects; muscles attach; cornea focuses
What is the choroid?
vascular-delivers O_2 and nutrients to retina; iris; ciliary muscle/body
What is the retina?
inner-neural, photoreceptors(respond to light)
Where is the anterior chamber
cornea to iris
Where is the posterior chamber
iris to lens
What does the ciliary body do
produces aqueous humor
What do the suspensory ligaments of the ciliary body do
hold lens
What does the smooth muscle of the ciliary body do
Shapes lens(ring contracts and fattens lens)
What does the iris do
pupil=opening; size controlled by pupillary dilator and constrictor m.
What is visual axis?
line from object to retina
Where does light travel in order
cornea-aqueous humor-lens-vitreous body-retina-choroid
Describe macula
highest concentrations of photoreceptors
Describe fovea
depressed, central part of macula, sharpest vision(look directly at object)
Describe the optic nerve
carries information from the retina to the brain
What is the optic disc
The blind spot, that has no photoreceptors so there is no image detection
What is auricle
cartilage
What is the tympanic membrane
ear drum the separates external from middle ear
What is the internal acoustic meatus
lined with hair and cerumen; otitis externa
air filled
What are auditory ossicles
malleus, incus, stapes: connect tympani to cochlea
What is the auditory tube
connects middle ear with nasopharynx; equalize pressure
What is otitis media
infection of the middle ear
Describe the tympanic membrane. What is in it?
Auditory ossicles
- malleus
- incus
- stapes
What number is the vestibulocochlear nerve
CN-VIII
What is the bony labyrinth
with an internal membranous labyrinth
- fluid filled
1) Semicircular canals-rotation
2) Vestibule-gravity and linear acceleration
3) Cochlea-hearing
Describe semicircular canal
hair cells that respond to ROTATION(fluid only)
Describe vestibule
hair cells that respond to GRAVITY and LINEAR ACCELERATION
-otoliths
What is the cochlea’s function
hearing
