special senses Flashcards
olfaction cell types
olfactory neuron, basal cells, supporting cells, and olfactory glands
where are taste buds
lingual papillae
taste buds contain many…?
spindle cells, like gustatory cells and basal cells
salt
opens Na2+ channels depolarizes
voltage gated CA2+ channels open
exocytosis
sour
H+ (acid) enter cell through h+ channel OR H+ block k+ channel
gustatory cell depolarizes
voltage gated CA2+ channels
exocytosis
vison
lens: focusing light
Anterior cavity (eyeball)
filled with aqueous humor (fluid)
posterior cavity (eyeball)
filled with vitreous humor (gel) for eye shape
three layers of an eyeball
fibrous layer: CORNEA, matrix of collagen and nerve endings. SCLERA, whites of eye, connective tissue, maintains eye shape
Vasular tunic layer: CHOROID, vascularized layer covering eye pigment&absorb photon. CILIARY BODY, secretes nutrient fluid into AC, IRIS, regulates quantity of light entering pupil.
Innermost retina layer: NEURAL LAYER, photoreceptors(rods&cons), PIGMENTED LAYER, single cell think absorb light
Rods
photoreceptors in retinal layer with bipolar cells. sensitive to light and responsible for vision at low light, DONT discriminate color
Cons
photoreceptor in retinal layer with bipolar cells. responsible for color vision and require higher light to be stimulated
rods and cons segments
Inner segment: contain organelles
Outer segment: have siscs that contain visual pigments
visual pigments
derived from rhodopsin=opsin protein + pigment molecule retinal
parasympathetic nervous system
rest and digest, decreases the diameter of the pupil
sympathetic nervous system
fight and flight , increases the diameter of the pupil
focal point
spot that forms a shape image
light close source travels a longer focal distance to reach point
light from a distance source travels a shorter distance
ciliary muscle
changes the lens shape to adjust the focal point to reach the retina
retinal information?
received by visual cortex of the cerebrum to get processed
optic chiasm
area in brain where the optic nerves cross, vision from both eyes
emmetropia
normal vision, over 6 meters away
myopia
nearsightedness, eyeball is elongated or lens/cornea curvature is too great (what I have)
hyperopia
far-sightedness eyeball is shallow or lens/cornea is too flat, focal point is past the retina
presbyopia
lens becomes less elastic (often w/age)
three major parts of ear
External ear
middle ear
internal ear
external ear
consists of auricle, external acoustic canal, tympanic membrane. funnels sound into the inner ear parts. sound waves causes the tympanic membrane to vibrate
middle ear
consists of 3 bones call ossicles that amplify sound. malleus & incus & stapes
internal ear
consists of vestibule, semicircular canals and cochlea
vestibule(ear)
connects the tympanic cavity & the cochlea
semicircular canals
sensory cells that detect angular motion of head (dynamic equilibrium)
Cochlea
boney spiral canal that contains hair cells function for hearing selection of sound waves
types of hair cells
inner hair cells:detect sound
outer hair cells: modify sound reception by changing the stiffness of basilar membrane based on feedback from CNS
what are hair cells?
have microvilli(stereocilia) mechanicallly gated cation channels
when bent the channels open, K+ move into cell, cell depolarizes, open voltage gated Ca+ channels, Ca+ enters hair cell, trigger exocytosis,
stereocilia bent to one direction?
hair cell depolarization, action potential rate increases
stereocilia bent in opposite direction?
hair cell hyper depolarizes action potential rate generation decreases
sound
waves of alternative areas of high pressure and low pressure
higher frequency sound
higher pitch
higher amplitude
greater loudness sound intesnsity
hearing damage
hair cells cannot be regenerated
static equilibrium
measures orientation related to gravity. hair cell cilia project into Otholiths, head tilts the otoliths shifts pulling gel in a different direction
dynamic equlibrium
measures acceleration, deceleration, & rotation in the endolymph. Endolymph pushes on the capula
Kinocilium bent away from stereocilia
open mechanical gated channels and K+&Ca+ move into the hair cells
Kinocilium bent towards the stereocilia
close the mechanically gated channels and result in hyper-polarization of the hair cell
