chapter 13- General and special senses

4 types of papillae

filliform, fungiform, vallate, and foliate

filliform

anterior 2/3 of tongue, no taste buds

fungiform

tip and sides of tongue, few taste buds

vallate (circumvallate)

Back of tongue, largest

Foliate

lateral tongue, taste buds during infancy

basal cells

replace the other 2 cell types, immature

gustatory cells

-chemoreceptors

replaced every 7-10 days

supporting cells

support other cells in tate bud

what do chemoreceptors do?

react to chemicals

what type of muscle is the tongue surface

stratified squamous epithelium

5 flavors detected over broad regions of the tongue

salty

sweet

sour

bitter

umani (savory)

what are the 2 nerves involved with taste

facial nerve (VII)

• innervates anterior 2/3 of tongue

glossopharyngeal nerve (IX)

• innervates posterior 1/3 of tongue

which type is papilae only found in infants?

folliate- lateral part of tongue

what does gustatory cells connect to

neurons

oflaction receptor neurons- what kind of receptors?

chemoreceptors, bipolar neurons

what types of cells are in olfaction

supporting cells

basal cells

loss of smell is called what?

ansomia

Label- axons of CN1, Olfactory bulb, cubiform plate, olfactory gland, olfactory epithelium, mucus layer, supporting cell, olfactory receptor neuron

when we smell things, tiny particles (chemicals) bind to __1__ which causes __2_ to send action potential through axons into the _3__ lobe where we percieve smell

1,2-dendrites of olfactory receptor neurons, 3-temporal lobe

list the accessory structures of the eye and their functions

conjunctiva- covers eye’s anterior surface and internal eyelid surface

eyebrows, eyelashes and palpebrae(eyelids)- prevent foreign objects from contacting the eye

lacrimal system (lacrimal glands, canaliculi, lacrimal sac, and nasolacrimal duct) how tears are made and the flow of tears

tarsal glands- secretes oil to keep moisture in eye and prevents things from coming into eyes

list the flow of tears in order

lacrimal glands, canalicula, lacrimal sac, and nasolacrimal duct

eye structures

1. lens

2. pupil

3. anterior chamber- filled with aqueous humor

4. posterior chamber- filled with aqueous humor

5. vitreous chamber- filled with vitreous humor

6. optic nerve

list tunics and what is included

Fibrous Tunic

1. sclera- white part of eye

2. cornea- (where contacts go)

Vascular tunic

3. choroid- layer of vascular tissue around eye

4. ciliary body- made up of muscles that connect to suspensory ligaments that hold lens

5. suspensory ligaments- hold lens

6. iris- controls amount of light that hits the lens

Neural tunic

7. retina

• photoreceptors

when ciliary body contracts, it pulls on suspensory ligaments which helps what?

helps our lens focus on what we’re looking at

what type of muscle helps pupils constrict and dilate

smooth muscles help contract and relapse

fovea centralis vs optic disc

fovea centralis- contains ONLY cones, maximal visual acuity

Optic disc- contains NO rods or cones, axons exit eye, blind spot)

Rods Vs Cones

Rods- function in dim light, don’t provide sharp vision or color vision, more numerous than cones

Cones- operate best in bright light, provide high acuity color vision

what is the part/center of the macula utea

fovea centralis

what does it mean when someone has 20/20 vision

lens magnifies and concentrates right on fovea centralis

myopia vs hyperopia

mypoia- nearsightedness

hyperopia- farsightedness

name and explain structures in external ear

auricle- outer ear; groves that tunnel sound to →

external acoustic meatus

ceruminous glands

• produce cerumen

• earwax impedes microorganism growth

tympanic membrane

name and explain structures in middle ear

ossicles-

• malleus

• incus

• stapes (oval window is beneath the footplate in the stapes)

• stapedius muscle

• tensor tympani muscle- contracts (like at a concert to keep eardrum from moving too much)

• auditory tube- connects air-filled middle ear to nasopharynx

auditory tube

connects air-filled middle ear to nasopharynx

ususally closed, opens to equilibrate pressure in middle ear

otitis media- infection of the middle ear

name and explain structures of inner ear

vestibule

• utricle and saccule

• detects acceleration and decleration

• helps sense equillibrium

semicircular canals

• detect rotational movements

• help sense equillibrium

cochlea

• senses autdition

vestibular and cochlear nerves

when the fluid pushes all the way back in vestibule, is it acceleration or deceleration?

acceleration

semicircular canals- if you spin really fast and then stop suddenly in your chair, why do you feel dizzy

the fluid in the semicircular canals keeps spinning til it it slows down

name the journey of sound after entering external auditory canal

1. tympanic membrane

2. Malleus

3. Incus

4. Stapes pushes on oval window

5. cause fluid movments within cochlea

6. goes through scala vestibuili

7. waves transported and causes movement within cochlear duct

8. pass through cochlear duct

9. cause fluid to move through scala tympani

scala vestibuli and scala tympani are filled with what?

perilymph fluid

endolymph is found where?

cochlear duct

journey of sound inside cochlea

1. crosses scala vestibuili

2. vibrate vestibular membrane

3. cause vibration within cochlear duct

4. cause basilar membrane and hair cells to vibrate and hit tectorial membrane that creates perception of sound

conductive hearing loss

sound isn’t conducted efficiently through the outer or middle ear

sensorineural hearing loss

damage to the inner ear or nerve pathways

cochlear implant

1. the antenna, transmitter, and receive are inserted in the skin posterior and superior to the auricle. sound waves are received here and turned into electrical impulses

2. transmitter lead is inserted through the external ear, the middle ear, and the cochlea of the inner ear

3. electrical impulses from the transmitter are relayed through a lead and stimulate the cochlear nerve directly adjacent to the cochlea

cataracts

eye disorder

cloudy lense

ex: proteins in lens could start breaking down

usually old age

macular degeneration

eye disorder

area around fovea degenerates

Billy woke up one morning and realized that he had lost the sense of smell. we would diagnose that symptom of ___

anosmia