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110 terms

Chapter 17: Special Senses

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General Senses include:
somatic sensations, visceral sensations
Somatic sensations include:
tactile, thermal, pain, and proprioceptive
where are general senses located?
scattered throughout the body
What kind of sturcture do general senses have?
simple structures
Special senses include:
smell, taste, vision, hearing, and equilibrium
Where are the special senses located?
concentrated in specific location in the head
What kind of structures do special senses have?
anatomically distinct structures
Sense of smell is also callled what?
olfaction
what kind of receptors are smell receptors?
chemoreceptors
How many receptors are in the olfactory epithelium?
between 10-100 million
What are cilia?
tiny hair like structures
location of the olfactory organs
upper nasal cavity, superior nasal conchae and a portion of the nasal septum
what do olfactory organs consist of?
receptor cells, supporting cells, basal stem cells
the cilia are sensitive to what kind of change?
chemical concentration
Columner epithelial cells provide:
physical support, nourishment, electrical insulation, detoxify chemicals
What is unusual about Basal Stem Cells?
they continuously divide
about how many oders can you detect?
about 10,000
process of sensing an oder
olfactory hair, g-protein activation, activation of odenylate cyclase, opening of Na+ channels, infow of Na+, generator potential, nerve impulse through olfactory nerves, olfacotry bulbs, olfactory tract, cerebral cortex
speed of olfactory receptors adaptation
quickly
Papillae
elevated part of the tongue
what is located on the papillae
taste buds
three types of epithelial cells of taste buds
supporting cells, gustatory receptor cells, basal cells
how many gustatory hari cells per taste buds?
50
Water (saliva)
chemicals must be dissolved in this in order to be tasted
5 types of taste
sweet, sour, salty, bitter and umami
Location of sweet receptors
tip of tongue
location of sour receptors
lateral edges of the tongue
location of salt receptors
tip and upper lateral portion of the tongue
location of bitter receptors
posterior of the tongue
location of the umami receptors
posterior of tongue
Speed of taste receptors adapting
quickly
Taste impulses travel on what 3 nerves
facial, glossopharyngeal, vagus
3 regions of hearing
external, middle, and internal
parts of the external ear
auricle, external auditory canal, tympanic membrane
Parts of the middle ear
auditory ossicles: malleus, incus, and stapes auditory tube
parts of the internal ear
labyrinth (bony and membranous)
Bony labyrinth is
perilymph
Membranous labyrinth is
endolymph
Location of oval and round window
membranous region
length of external auditory meatus
2.5 cm long
what does the auricles collect?
sound waves
another name for the tympanic membrane
eardrum
air filled space in the middle ear
tympanic cavity
what do the auditory ossicles do?
transmit vibrations between the external ear and inner ear and amplify sound waves
malleus
attached to the eardrum, vibrates when the eardrum does
incus
passes vibrations from the malleus to the stapes
stapes
acts like a piston in the oval window transmitting vibrations to fluid in the inner ear
What does the fluid in the inner ear stimulate
hearing receptors
auditory or eustachion tube
connects the middle ear to the nasopharynx to help maintain equal air pressure on both sides of the eardrum
what makes the popping sound in your ears?
the ear is equalizing the pressure on both sides of the eardrum
ear infections
occure in the audiory tube
round window
opening of inner ear into middle ear
what is the round window covered by?
tympanic membrane
Tensor tympanic and stapedias muscles
attach to ossicles, help dampen large vibration of stapes protect oval window
labyrinth
inner ear is made up of a complex system of communicating chambers and tubes
2 types of labyrinths
membranous and osseous
Perilymph
extracellular fluid located within the cochlea
Perilymph and endolymph regulate
electrochemical impulses of hair cells
location of endolymph
inside the membranous labyrinth
names of the semicircular canals parts
anterior, posterior, lateral
cochllea
snail shaped, contains a bony core and a thin bony shelves
parts of the cochlea
scalla bestibuli, scala tympani, bistoibular membrane, basilar membrane
scala bestibuli
chamber in the bony labyrinth above the cochlear duct, opens to the oval window
scala tympani
chamber below the cochlear duct, opens to the round window
vistibular membrane
seperates the cochlear duct from the scala vestibuli
basilar membrane
separates the cochlear duct from the scala tympani
cochlear duct
chamber in the membraneous labyrinth which contains hearing receptors
Spinal organ
organ of hearing, rest on the basilar membrane inside of the cochlear duct
what kind of cells does the spiral organ have?
hair cells and supporting cells
first step of generating a sound
auricle directs sound waves into the external auditory meatus
2nd step of generating a sound
sound waves strike the eardrum causng it ot vibrate
3rd step of generating a sound
auditory ossicles amplify and transmit vibrations to end of staeps
4th step of generating a sound
movement of stapes at the oval window sets up fluid pressure waves in perilymph of cochlea
5th step of generating a sound
pressure waves are transmitted formt eh scala vestibuli to sala tympani and eventually the round window
6th step of generating a sound
as the pressure waves deform the walls of the scala vestibuli and scala tympani, they pusth the vestibular membrane back and forth
7th step of generating sounds
different fraquences of vibrations in endolymph stimulate ifferent sets of recepter cells
8th step of generating sounds
as a receptor cell depolerizes its membrane becomes more permeable to calcium ions
9th step of generating sound
inward diffusion of calcium ions causes vesicles at the base of the receptor cell to release neurotransmitters
10th step of generating sound
neurotransmitters stimulate ends of nearby sensory neurons
11th step of generating sound
sensory impulses are triggeredon fibers of the cochlear branch of bestibulocochlear nerve
12th step of generating sound
nerve fibers carry impulses ot the auditoyr coctrices of the temporal lobes where they are interpreted
13th step of generating sound
audiory cortex of temporl lobe interprets sensory impulses
frequency of normal hearing
20-20,000 or more vibrations per second
2 types of equilibruim
static and dynamic
what does satic equilibrum maintain
position of the head whenthe head and body are still
what does dynamic equilibrum naintain
maintain balance when the head and body suddenly move and rotate
where are the organs of the static equilibrium located
vestibule of the inner ear and inside the utricle and saccule
macula
tiny structure, consisting of hair cells, supporting cells
location of macula
inside the utricle and saccule
otoliths
grains of cacium carbonate
semicircular canals
detect motion of the head, and they aid in balancing the head and body during duddne movement
cristae ampullans
organs of the dynamic equilibrium
location of cristae amullans
in the ampulla of each emicircular canal of the inner ear
rapid turning of the head or boyd generates impulses of the what?
cupula and hair cells bend
eyelids
protects eye from foreign objects
4 parts of the eyelid
skin, muscle connective tissue and conjunctiva
skin
thinest skin of the body
2 types of muslces in the eylid
orbicularis oculi, lavator palpebrae suerioris
orbicularis oculi
sloses the lids when it contracts
labator palpabrae supererioris
raises the upper lid thus helps open the eye
connective tissue
holds the different layers together
conjunctiva
mucous membrane that lines the inner surfaces of the eyelids
3 parts of the lacrimal apparatus
nasolacrimal ducts, lacrimal ducts, lacrimal glands
nasolacrimal ducts
two small ducts drain tears into the nasal cavity
lacrimal ducts
empy into the dedical corner of the eye
lacrimal glands
produce and secrete tears continuoulsy
function of tears
lubricate, cleanse, antibacterial agents
extrinsic mustle
attach to the sclera and move the eye in all directions
2 different types of extrinsic muscles
rectus and oblique
6 types of extrinsic eye muscles
superior rectus, inferir rectus medial rectus, lateral rectus, superior oblique, inferior oblique