a&p unit 8: Special Senses

sensation

brain receiving input from sensory organs

perception

brain making sense out of the input

projection

process where the cerebrum causes a feeling to stem from a source

sensory receptors structure

specialized structures at the end of peripheral nerves in the body

sensory receptors function

detect environmental changes to trigger nerve impulse from PNS to CNS for processing and interpretation

mechanoreceptors

pressure, touch, vibrations

thermoreceptors

temp

photoreceptors

light energy (retina)

chemoreceptors

chemical (taste and smell)

nocireceptors

pain, tissue damage

conjuctiva

inner lining of eyelid

lacrimal apparatus

lacrimal gland and nasolacrimal duct

lacrimal gland

upper lateral surface of the eye that produces tears contacting the lysozyme to lubricate and protect the eye

nasolacrimal duct

carriers tears to nasal cavity (drainage)

extrinsic muscles

muscles that move the eye

superior and inferior rectus

moves eye up and down

lateral and medial rectus

move eye horizontally

superior and inferior oblique

muscles that rotate the eye up and away, and down and away

cornea

transparent anterior portion of eye that focuses light

sclera

white part of eye, protects eye and provides attachment for muscles

choroid coat

joined to sclera, contains blood vessels and melanocytes

ciliary muscles

control shape of lens

suspensory ligaments

hold lens in place

accomodation

lens change shape to facilitate focusing

iris

colored ring around pupil, thin, regulates light, separates anterior cavity into anterior and posterior chambers

what is the iris filled with

aqueous humor

retina

location of rods and cones

rods

night vision, silhouettes

cones

color vision, sharp images

optic disk/blind spot

where nerve fibers leave eye and join optic nerve

fovea centralis

area of sharpest vision

the posterior cavity of the eye contains what

vitreous humor

sense of smell location

upper nasal cavity

olfactory epithelium

a specialized tissue in the nasal cavity that detects odors and contains sensory receptors for smell

receptor cells classified by structure

bipolar neurons

olfactory hairs

cover dendrites and project into nasal cavity

where is the olfactory nerve pathways synapse

olfactory bulb

primary neuron in olfactory nerve pathway

olfactory receptor cell

secondary neuron in olfactory nerve pathway

olfactory bulb

sense of taste location

tounge

circumvallate

taste buds located on the back of the tongue responsible for detecting bitter tastes

foliate

type of taste bud located on the sides of the tongue, involved in sensing savory flavors

fungiform

taste buds located primarily on the anterior part of the tongue that detect sweet and salty flavors

eiliform

Taste buds located on the surface of the tongue, responsible for detecting different taste qualities

taste hairs (microvilli)

protrude from taste cells

taste pore

opens to free surface

taste nerve pathway

The pathway that transmits sensory taste information from the taste buds to the brain, primarily involving cranial nerves VII, IX, and X, which triggers impulse to brain and coordinates taste perception

sweet taste sensations originate where

tip of the tounge

sour taste sensations originate where

sides of the tongue

salt taste sensations originate where

perimeter of tounge`

bitter taste sensations originate where

back of the tongue

umami taste sensations originate where

the center of the tongue

sense of hearing location

cochlea

auricle/pinna

the outer ear structure that funnels sound waves into the ear canal, aiding in hearing

external auditory meatus

ear canal, directs sound waves to tympanic membrane

tympanic membrane

eardrum, sound causes it to contract which effects ossicles

middle ear

amplify and concentrate sound waves

auditory ossicles

transmit vibration, MIS

malleus (hammer)

connected to TM

incus (anvil)

middle bone

stapes (stirrup)

transmits vibrations to entrance to inner ear (oval window)

auditory (eustachian) tube

connects middle ear to throat, maintains air pressure on both sides of the eardrum

labryinth

interconnecting chambers and tubes

2 types of labyrinth

bony labyrinth and the membranous labyrinth

2 types of fluid in labyrinth

perilymph and endolymph

cochlea

snail shaped, organ of corti

semicircular canals

3 rings, dynamic equilibrium

vestibule

between cochlea and canals, static equilibrium