special senses Flashcards
receptor of pain
nociceptor
receptor of temperature
thermoreceptor
receptor of touch
mechanoreceptor
receptor of pressure
mechanoreceptor
receptor of vibration
mechanoreceptor
receptor of proprioception
proprioceptors
what are the 5 special sense
smell, taste, vision, hearing, equilibrium
3 types of cells of olfaction
- Olfactory receptor cells
- Supporting cells
- Basal stem cells
type of neuron of olfactory receptor cell
bipolar neurons
function of olfactory receptor cells
• Respond to chemical stimulation of an odorant molecule - initiate the olfactory response
what is the olfactory receptor cells
• Single axons project through cribiform plate into the olfactory bulb
composition of supporting cells of olfaction
Columnar epithelial cells which line the nose
function of supporting cells of olfaction + nerve involve
• Provide physical support, nourish, and insulate the
olfactory rec. cells
• Help detoxify the chemicals which come in contact with olfactory epithelium
- CVII
location of basal stem cells
Lie between the bases of supporting cells
function of basal stem cells
Continually undergo cell division to produce new olfactory receptor cells • 1 cell lives ~ 1 month • # decreases with age • decreased sensitivity with age
olfactory pathway
olfactory receptor cell, olfactory nerve than pass through cribriform plate, goes to olfactory bulb and olfactory tract until primary olfactory area in cerebral cortex
what are the 5 majors classes of stimuli
sour, sweet, bitter, salty, Unami
how does taste occurs
Odors from food pass up into nasal cavity - stimulate olfactory receptor cells
location of receptor of taste
taste buds
location of taste buds
tongue, soft palate, pharynx, larynx, in papillae
is taste buds decrease with age
yes
3 cells of taste buds
supporting cell, gustatory receptor cells, basal cells
pathway of gustatory receptor
Gustatory receptor cells synapse with dendrites of a sensory neuron - branch out and contact many gustatory receptor cells in several taste buds
gustatory pathway
- From taste buds, impulses propagate along these cranial nerves to the medulla oblongata
- Some taste fibers will project to limbic system areas and hypothalamus
where does taste fibers project to
limbic system, hypothalamus, thalamus and to primary gustatory area in parietal lobe
where is contain the sebaceous (oil) glands and sudoriferous (sweat) glands
lacrimal caruncle
what are the layer of eyelid from sup to deep
epidermis, dermis, subcutaneous tissue, orbicularis oculi muscle, tarsus, cunjunctiva (palpable )
function of eyelashes and eyebrows
- Protect eyeball from foreign objects
- Protect eyeball from perspiration
- Protect eyeball from direct rays from sun
function of sebaceous glands
release a lubricating fluid into the hair follicles (infection = sty)
function of lacrimal apparatus
produce and drain lacrimal fluid, protect, clean, lubricate
what is contain in the watery solution of lacrimal apparatus
salt, mucous, llyzosysme
action of superior rectus m.
moves eyeball superiorly and medially
action of inferior rectus
moves eyeball inferiorly and medially
action of lateral rectus
abduct eyeball
action of medial rectus
adduct eyeball
action of sup oblique
moves eyeball inferiorly and laterally
action of inf oblique
moves eyeball superiorly and laterally
what are the 3 layers of eyeball sup from deep
fibrous tunic, vascular tunic, retina
2 part of the fibrous tunic
anterior cornea
post sclera
function of anterior cornea
helps focus light into retina
function of posterior sclera
give shape and protect inner part of eyeball
which part give the white of the eye
sclera
which part of the eye is transparent
cornea, lens
what are the 3 part of the vascular tunic of eyeball
choroid, ciliary body, iris
function of choroid
provides nutrient to retina
function of ciliary body (muscle)
alter shape of lens
function of iris
respond to change in light level
what happens with pupil when there is bright light
pupil constrict as circular muscle of iris contract (parasympathetic)
what happens with pupil when there is dim light
pupil dilate as radial muscle of iris contract (sympathetic)
which muscle is responsible when pupil constrict
circular muscle
which muscle is responsible when pupil dilate
radial muscle
retina consist of
pigment epithelium and neural portion
which part of the retina is non-visual portion
pigment epithelium
which part of retina is visual portion
neural portion
what are the 2 photoreceptors
rods and cones
what allows us to see in dim light
rods
which photoreceptor is stimulate by brighter light
cones
which photoreceptor produce coloraturas vision
cones
which photoreceptor is stimulated at low light threshold
rods
what is contains in fovea centralis
cones
function of fovea centralis
sharpness of vision
where is the optic disc
blind spot
in which part of the eyes there’s no rods or cones
optic disc
which structure of eyes is avascular
lens
position of lens
posterior to pupil and iris
what is the composition of lens
protein (crystalline)
what is helding lens in place
suspensory lig
function of lens
- Fine tunes focusing of light rays
* Facilitates clear vision
which cavity is the aqueous humor
anterior
which cavity is the virtuous humor
posterior
visual pathway in the retina
- Beginning of significant processing of the visual signals
- Axons of the retinal ganglion cells provide output from the retina to the brain
- Rods and cones will release neurotransmitters which lead to the generation of nerve impulses
visual pathway in the brain
- Axons of optic nerve pass through optic chiasm
- Some fibers cross to the opposite side, others remain uncrossed
- After the optic chiasm, the fibers form the optic tract, enter the brain and terminate in the thalamus (some bypass and go directly to sup. colliculi)
- Optic radiations project to visual areas in the occipital lobes of the cerebral cortex (after synapsing in the thalamus)
what is contain in the external ear
auricle, external acoustic meatus, tympanic membrane
how is the auricle attached to the head
lig and muscle
where does the external acoustic meatus is
temoral bone
what does secrete ear wax
Specialized oil glands (ceruminous) secrete ear wax (cerumen)
role of wax
Along with hair, protect from dust / foreign objects
location of tympanic membrane
Thin, semi-transparent membrane between auditory canal and middle ear
the tympanic membrane is cover by what
epidermis
what are the 3 bones located in middle ear
- Malleus (hammer)
- Incus (Anvil)
- Stapes (Stirrup)
what is the middle ear
Air filled cavity lined with epithelium
what is contain in the ossicle
malleus, incus, stapes
what Articulates with tympanic membrane and incus
malleus
what Articulates with stapes and malleus
incus
what Articulates with incus and sits on oval window
stapes
what are the muscle attaching to ossicle
- Tensor Tympani Muscle
* Stapedius Muscle
composition of Eustachian tube
bone and hyaline cartilage
what connect the Eustachian tube
middle ear and nasopharynx
role of Eustachian tube
Allows air to enter / leave the middle ear until: • pressure in middle ear = atmospheric pressure
in which part of inner ear there is perylymph
outer bony labyrinth
what is contain in the outer bony labrinth
- Semi-circular canals
- Vestibule
- Cochlea
- Contains perilymph (similar to CSF)
contain of inner membranous labyrinth
- Utricle and saccule
- Semi-circular duct
- Contains endolymph (high concentration of K+ ions)
in which part of the inner ear there is endolymph
inner membranous labyrinth
2 branch of vestibulocochlear nerve
vestibular cochlear
function of vestibular branch
sensory and motor
function of cochlear branch
sensory: hearing
which nerve branch off the vestibular branch
Ampullar, Utricular and Saccular nerves
what create the equilibrium
synapse of vestibular branch with receptor cells
location of cochlea
anterior to vestibule
spiral around modulus
3 channels of cochlea
scala vestibolo
scala tympani
cochlear duct
where does Scala vestibuli end
oval window
where does Scala tympani end
round window
what separates cochlear duct from scala vestibuli
vestibular membrane
what separates cochlear duct and scala tympani
basilar membrane
role of basilar membrane
separate cochlear duct and scala tympani
role of vestibular membrane
Separates cochlear duct from scala vestibuli
location of organ of corti
on basilar membrane
composition of organ of corti
Coiled sheet of epithelial cells
role of organ of cortisones
receptor for hearing
where does organ of corti synapse
Synapse with sensory and motor neurons from the COCHLEAR branch of CN VIII
what is the mechanism of hearing
- sound enter in external auditory canal
- sound wave on tympanic membrane
- sound travel into malleus than incus
- stapes vibrate in oval window
- vibration of oval window create vibration on vestibular membrane which make the sound travel in Scala vestibuli than into helicotrema, than cochlea, than Scala tympani
- the vibration than spread into basilar membrane into organ of corti
- then the basilar membrane create a vibration into the secondary membrane in round window