anatomy exam 4 -hearing, vision, gustatory, olfaction

what is a sensation?

conscious awareness of the stimuli

what is transduction?

converted into impulses

what is perception?

brain assigns meaning to stimuli

what are general senses?

temperature, pain, touch, stretch, and pressure

distributed throughout skin and organs

what are special senses?

gustation, olfaction, vision, equilibrium, hearing

in complex organs

what are sensory receptors?

detect stimuli

what are chemoreceptors?

detect specific molecules dissolved in fluid

what are thermoreceptors?

detect changes in temperatures

what are photoreceptors?

detects changes in intensity, color and position of light

what are mechanoreceptors?

detect touch, pressure, vibration, and stretch

what are baroreceptors?

detect pressure changes within body structures

what are nociceptors?

detect painful stimuli

what is phantom pain?

sensation associated with a part of the body that has been removed

what is referred pain?

impulses from certain viscera are perceived as originating from the skin

what are tactile receptors?

sense friction

what is gustation?

sense of taste

what are gustatory cells?

taste receptors houses in taste buds

detect tastant (molecules and ions)

what are taste buds?

located in dorsal surface of tongue

with epithelial and connective tissues called papillae

what are the five sensations of gustatory?

sweet

salty

sour

bitter

umani

what is the pathway of gustatory?

gustatory cells

facial/glossopharyngeal nerve

insula

what is olfaction?

sense of smell

what are odorants?

dissolved in mucus of nasal cavity that are detected

(molecules in the air)

what is olfactory epithelium?

lines superior nasal cavity

what are olfactory nerves?

formed by bundles of axons of olfactory cells

what is the pathway for olfaction?

olfactory nerve

olfactory bulb

olfactory tract

temporal lobe

what are the accessory structures of the eye?

extrinsic muscles

eyelids

medial canthus

lateral canthus

lacrimal caruncle

what is the medial canthus?

inner corner

where upper eyelid meets lower eyelids

what is the lacrimal caruncle?

only on medial side

what is the conjunctiva?

lining of the eyelids and over the anterior surface of eye

what is conjuctivitis?

inflammation of conjunctiva

pink eye

what is the lacrimal apparatus?

produces, collects, and drains lacrimal fluid from the eye

contains lacrimal gland, canaliculi, sac, and nasolacrimal duct

what is the lacrimal gland?

produce and secrete tears

what is the lacrimal canaliculi?

where excess tears that drain through

what is the anterior cavity of the lens?

located at the front of the lens

circulate aqueous humor

what is the posterior cavity of the lens?

located behind the lens

contains vitreous humor

what are the 3 eye wall layers?

fibrous tunic

vascular tunic

retina

what does the fibrous tunic?

maintain shape of the eye

what does the vascular tunic do?

contain many blood vessels

what does the retina do?

contains photoreceptors

what is glaucoma?

increase pressure within the eye

too much aqueous humor

what are the two regions of the fibrous tunic?

cornea

sclera

what is the cornea?

clear part that covers the iris, pupil, and anterior chamber

what is the sclera?

white part of the eye

what are the 3 regions of the vascular tunic?

choroid

ciliary body

iris

what is the choroid?

contains capillaries supplying nutrients and oxygen to the retina

what is the ciliary body do?

changes lens change

what does the iris do?

pigmented part of eye

what is the pupil and what does it contain?

controls amount of light entering the eye

contains sphincter pupillae and dilator pupillae

what are the 3 layers that form the neural layer?

photoreceptors

bipolar cells

ganglion cells

what are rods?

rods see black and white and dim light

night vision

low acuity

what are cons?

cons see color and precise vision

day vision

high acuity

in fovea

what is the optic disc?

blind spot on retina lacking photoreceptors

what is the fovea centralis?

contains highest proportion of cones

sharpest vision

located in the macula lutea

what is the lens?

accommodation: lens ability to change shape to focus an image

what is the visual pathway?

cornea

anterior cavity

lens

posterior cavity

retina

optic nerve

optic chiasm

optic tract

optic radiation

occipital lobe

what is 20/20 vision?

normal

when is vision better than normal?

bottom number is lower

20/15

20/10

when is vision worse than normal?

bottom number is higher

20/40

20/50

what is myopia?

eyeball is longer, can see close, inability to focus far away

treatment: surgery, glasses, contacts

what is hyperopia?

eyeball is too short

inability to focus on things close by

treatment: glasses and surgery

what is presbyopia?

age related farsightedness

what is astigmatism?

irregularity on lens and cornea (bump)

treatment: lens for astigmatism

what are cataracts?

lens that becomes cloudy from aging

lens can be replaced

what is diabetic retinopathy?

person with diabetes develops unstable blood vessels that prone to rupture causing blindness

what is strabismus?

imbalance of strength between left/right extrinsic muscle

treatment: can patch the eye to build muscle or surgery

what are the 3 distinct anatomic regions?

external ear

middle ear

inner ear

what does the external ear contain?

auricle

external acoustic meatus

tympanic membrane

what is the auricle?

funnel shaped that sounds travel through

what is the external acoustic meatus?

opening in temporal bone to allow sound to travel

what is the tympanic membrane?

vibrates when soundwaves hit it and amplifies them

what does the middle ear contain

auditory tube

auditory ossicles

what does the auditory tube do?

connects middle ear to nasopharynx

what does the auditory ossicles do?

transmit sound waves to inner ear

what does the auditory ossicles contain?

malleus

incus

stapes

what is the inner ear?

close to temporal bone

equilibrium

hearing: cochlea

what is equilibrium?

awareness of head position

the vestibular apparatus consists of sensory receptors in…

utricles

saccule

semicircular

what does the utricle and saccule detect?

static equilibrium and linear acceleration

what do the semicircular ducts detect?

angular acceleration

what is the maculae?

contain hair cells

within the utricle and saccule

what is static equilibrium?

when head tilits otoliths push on gelatin layer bending hair cells

what is dynamic equilibrium?

3 semicircular canals

receptors detect rotational movement

ampulla is in each semicircular canals

what is the crista ampullaris?

elevated region of ampulla covered by hair cells

structure in dynamic equilibrium

what is cupula?

hair cells embed into an overlayering gelatinous dome

structure of dynamic equilibrium

what is the cochlear duct?

filled with endolymph

within cochlea

what are the two chambers of cochlea duct?

scala vestibuli

scala tympani

what is the spiral organ/organ of corti?

contains hair cells

what is tectorial membrane?

extensions of hair cells in spiral organ with gelatinous mass

what is the auditory cortex?

interprets sensory impulses

what is pitch discrimination?

sound waves of various frequencies stimulate different parts of basilar membrane

what is loudness discrimination?

loudness depends on amplitude of vibration

louder sounds cause tympanic membrane to vibrate more

what is tinnitis?

ringing in ears

resolves itself

what is conductive hearing loss?

fluid build-up in ear pathway

what is otitis?

inflammation of ear (ear infection)

externa, media, and interna

interna is most severe can affect hearing and balance

what is the pathway of hearing?

auricle

external acoustic meatus

tympanic membrane

malleus

incus

stapes

oval window

cochlea

cochlea duct

spiral organ

cochlear branch/nerve

vestibulocochlear nerve

temporal lobe