Nervous

System - Sense Organs

Lance GamboaCarl Tan

Peripheral Nervous System

sends information to the brain

carries information

from the brain to the

body

Sense Organs

from the environme

nt

The Sense of Taste–The Tonguetaste budscontain taste receptorsmostly found on raised protrusions of tongues called papillaecan taste sweet, salty, sour, bitter, or umami depending on the chemical stimulation

salivafood

The Sense of Smell–The Nose

nose

nostrils

nasal cavity

upper mouth

nostrilsthe holes of the nose through which air enters

nasal cavitya space behind the nose in the middle of the faceseparated from the oral cavity by the upper mouthconnects with the throat

mucus membra

nemucus

membrane

the lining of the nasal cavityproduces mucus that capture small particles from the airallows molecules that contain odor to dissolve for the nerves to detect

ciliasmall hair-like projections on the olfactory epitheliumconnected to the smell receptor neurons of the nosecovered with mucus

stimulated by odor molecules

olfactory bulbseparated from the

olfactory epithelium by a boneconnected to the smell receptorscontains the olfactory nerves that transmit nerve messages to the brainbelow the brain

Air

The Sense of Touch–The Skinmechan

oreceptorsensory receptors of

the skin that are stimulated by mechanical pressure/distortioninclude touch and pressure receptors

Merkel’s disks

most sensitive of all the skin mechanoreceptorscan detect distortions in the skin with size of 1 micrometer slowly-adapting receptorssenses light touch and how long an object has been touching the skin

Meissner’s corpusclesthe second most

sensitive of all the skin mechanoreceptorsrapidly-adapting receptors

can sense vibrations, texture, and light touch

Pacinian corpuscles

the pressure mechanoreceptor

lies deeper within the skin

rapidly-adapting sensory receptors

detect gross pressure changes and vibrations

Ruffini corpuscles

sensitive to skin stretchbelieved to monitor object slippage on the skin, allowing modulation of gripdetect mechanical changes within joints, especially angle changes

may also sense heat

Nociceptors

pain receptors

tissue

Thermoreceptors

receptors that respond to changes in temperaturecomes in two types: heat and cold receptorheat receptor: temperature above body temperaturecold receptor: temperature below body temperaturemore cold than heat receptors

The Sense of Sight–The Eye

ciliary muscle

vitreous body

white area of the eyetough material that covers the eyeball

anterior chamber

sclera

tough material that covers the eyeball

iriscolored area of the eye

has muscles that change its shape

pupilblack area of the eye

an opening in the iris

lets light enter the eyeshrinks when light is near but enlarges when there is little light

corneatransparent covering of the iris

protects the iris

helps focus light in the eye

anterior chamberspace between cornea and iris

contains a transparent fluidnourishes and keeps the eye healthy

lens

gathers light

focuses the light on the retina

works like a movie projector

ciliary musclechanges the shape of the lensthickens the lens when looking at something close up

thins the lens when looking at something faraway

vitreous body

gives the eye it shapecontains a clear , jelly-like material called vitreous humor

where light passes to from the lens to the retina

retinamembrane found at the back of the eyeballmade up of light-sensitive cells (rods and cones)rods–tell the form & shapecones–tell the colorprocesses the light image and converts it to nerve messages

optic nervecarries the nerve

messages to the brain

The Sense of Hearing–The Ear

Pinna

pinnathe ear flap that can be seen on the face’s sidescollects sound waves

directs sounds to the auditory canal

ear canal

outer ear middle ear inner ear

the tube that extends from the pinna to the eardrumcarries sound waves from the pinna to the ear drumsecretes cerumen (earwax) that aids in cleaning, lubrication, and protection

eardrumalso known as the tympanic membrane

transmits sound waves from the ear canal to the ossicles in the form of vibrations

separates the outer ear from the middle ear

ossiclesbones found in the tympanic cavity of the middle earconsist of the malleus (hammer), incus (anvil), and the stapes (stirrup)smallest bones of the bodyreceive vibrations from the eardrum, increase the force of these, and move these to the cochlea

hammer/malleusthe bone attached to the eardrum from which vibrations are passedanvil/incusbridges the hammer

(from which vibrations are passed) to the stirrupstirrup/stapesthe bone attached to the

anvil from which vibrations are passed and to the oval window’s membrane

oval windowmembrane-covered opening of the cochlealeads from the middle ear to the cochleareceives amplified vibrations from the stirrupcauses vibrations to occur in the cochlea’s fluids (together with the stirrup)

cochleaa spiral-shaped cavity in the inner earreceives vibrations from the force the stirrup exerts on the oval windowcontains fluids which vibrate after the stapes hits the oval windowcontains the organ of corti (the organ that contains au-ditory sensory receptor cells)

cochlear nervethe auditory nerve

that receives nerve impulses from the organ of cortithe nerve that carries these nerve impulses to the brain

sound waves

tectorial membrane

Thank you for listening!

Though I believe you were bored.