24. sense organs
TRANSCRIPT
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.