Liberty University-BIOL 213-Passburg FINAL EXAM

olfaction

the sense of smell

olfactory epitheliem

specialized epithelium locted in olfactory region of nasal cavity

olfactory region

a dime-sized area at the top of each nasal cavity that houses sensors responsible for smell

odorant

airborne molecules responsible for odors

low specificity

one chemoreceptor may respond to more than one type of odor

adaptation

receptors become saturated with odorants

Central Olfactory Pathways

Olfactory nerve synapses at the olfactory bulb which projects directly into the brain (avoiding the thalamus). The olfactory bulb wires to the limbic system.

olfactory cortex areas

involved in comple processing of olfactory stimuli perception

central olfactory cortex areas

conscious perception of smell

secondary olfactory cortex areas

emotion and autonomic responses to olfactory stimuli

taste buds

specialized sensory structures that detect gustatory stimuli

papillae

bumps on the surface of the tongue

filform papillae

most numerous; no tastebuds

vallate papillae

largest; least abundant; have taste buds

fungiform papillae

have taste buds

foliate papillae

contain most sensitive taste buds; decrease in number with age

gustatory cells

sensory receptors within a taste bud

taste types

sour, salty, bitter, sweet, umami

salty

results when Na+ diffuses into a cell, resulting in depolarization

sour

results when hydrogen ions (H+) of acids cause depolarization of taste cells

sweet

sensation from sugars, some carbohydrates, and some proteins

bitter

sensation produced by alkaloids, which are toxic

umami (savory)

sensation from amino acids such as glutamate

chorda tympani

Nerve that provides taste to anterior 2/3 of tongue

eyes

eyeball and lens

eyebrows

shade; inhibit sweat

eyelids (palpebrae)

with conjunctiva

palpebral fissure

space between eyelids

canthi

lateral and medial; eyelids meet

caruncle

found in the medial canthus, it is a small fleshy mass containing sebacceous glands

tarsal plate

a thick fold of connective tissue that gives form and support to the eyelids

conjunctiva

thin transparent mucous membrane

palpebral conjunctiva

inner surface eyelids

bulbar conjunctiva

anterioir surface of eye except over pupil

pinkeye

acute contagious conjunctivitis

eyelashes

protect from foreign objects

ciliary glands

(modified sweat glands) empty into hair follicles

meibomian glands

at inner margins produce sebum

distichiasis

rare genetic disorder resulting in a double row of eyelashes

trichiasis

more common disorder resulting in eyelashes that grow inward toward the eye

sty

forms when ciliary glands become inflamed

chalazion

infection or blockage of a Meibomian gland

lacrimal gland

production of tears

extrinisc eye muscles

4 rectus muscles, 2 oblique muscles

H test

clinical test for normal eye movements

three eye tunics

fibrous, vascular, nervous

fibrous tunic

sclera and cornea

vascular tunic

choroid, ciliary body, iris

nervous tunic

retina

sclera

white outer layer

cornea

connective tissue matrix containing collagen, elastic fibers and proteoglycans

iris

colored part of the eye, controls light entering the pupil

sphincter pupillae

parasympathetic

dilator pupillae

sympathetic

ciliary body

produces aqueous humor that fills anterioir chamber

choroid

associated with sclera, very thin and pigmented

pigmented retina

outer, pigmented simple cuboidal epithelium

sensory retina

inner layer of rod and cone cells sensitive to light

macula lutea

small yellow spot

fovea centralis

area of greatest visual acuity; photoreceptor cells tightly packed

optic disc

blind spot

opthalmoscopic view of retina

Lens focuses light on macula lutea and fovea centralis

anterior compartment (eye)

anterior to lens; filled with aqueous humor

aqueous humor

fluid in the eye, found between the cornea and the lens

eye anterior chamber

between cornea and iris

eye posterior chamber

between iris and lens

glaucoma

abnormal increase in intraocular pressure

vitreous chamber

posterior to lens

vitreous humor

jellylike substance filling the vitreous chamber

eye lens

focuses light, adjusts for distance, loss of elasticity with age

suspensory ligaments

hold the lens in place

ciliary muscles

muscles which relax or contract and alter the shape of the lens

cataract

clouding of the lens of the eye

light refraction

bending of light

light convergence

light striking a convex surface

light focal point

point where light rays converge and cross

light focusing

causing light to converge

emmetropia

normal resting condition of lens

myopia

nearsightedness

hyperopia

farsightedness

focusing: close up objects

accommodation, pupil constriction, convergence

retina

Contains sensory receptors that process visual information and sends it to the brain

pigmented layer

filled with the pigment melanin

neural layer

photoreceptors, bipolar cells, ganglion cells

rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

cones

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

color blindness

results from dysfunction of one or more cones

external ear

hearing

middle ear

hearing; contains auditory ossicles

inner ear

hearing and balance

auricle (pinna)

elastic cartilage covered with skin

external auditory canal

lined with hairs and ceruminous glands

ceruminous glands

produce ear wax (cerumen)

tympanic membrane

eardrum

auditory tube

air passage between the middle ear and throat that equalizes air pressure on either side of the eardrum; also called the Eustachian tube

mastoid air cells

air spaces in the mastoid process of the temporal bone that communicate with the middle ear cavity

malleus

hammer; first of the three auditory ossicles of the middle ear

incus

anvil; middle of the three auditory ossicles of the middle ear

stapes

stirrup; last of the three auditory ossicles of the middle ear

oval window

connection between middle and inner ear