special senses Flashcards
general sense receptors
distributed throughout the skin and organs (touch)
special sense receptors
housed within complex organs in the head (smell,sight, taste)
tactile touch
MECHANORECEPTORS that react to touch, pressure, and vibration stimuli
LOCATED: dermis & subcutaneous tissue
Sensation
Conscious awareness of incoming sensory info
Touch
General sense
Keep homeostasis…feel pain
Located in dermis and subcutaneous tissue
Parietal lobe-sensory cortex
Nociceptors
.Trauma, pain, damage
.Respond to heat, mechanical stress, and chemicals-associated w tissue damage
Chemoreceptors
.chemicals
.respond to small concentration changes of specific molecules (chemicals)
.monitor blood composition (Na+, pH, pCO2)
.FOUND w/in aortic and carotid bodies
.VERY important for HOMEOSTASIS
Thermoreceptors
.Heat regulation… homeostasis
.Respond to changes in temp
.In dermis,skeletal muscle , liver and hypothalamus
.cold and warm receptor
Mechanoreceptors
.pressure
.respond to physical distortion of cell membrane (strectching, twisting, compression)
.3 types
*baroreceptors
*proprioceptors
*tactile receptors
-Merkel cells… function as touch receptors in association w sensory nerve endings
-meissners corpuscles…type of nerve endings responsible for sensitivity to light touch
Baroreceptors
TYPE OF MECHANORECEPTORS
sensitive to internal pressures; blood pressure, lung stretch, digestive tract tension
Proprioceptors
TYPE OF MECHANORECEPTOR
monitors muscle stretch
Tactile receptors
TYPE OF MECHANORECEPTOR
touch,pressure,vibration
-merkel cells; touch receptors associated w/ sensory nerve endings
-Meissner’s corpuscles; type of nerve ending responsible for sensitivity to light touch
what is our dominant sense/source?
vision
eyebrows
Part of eye:
keeps sweat and debris out of the eye
eyelids (palpebrae)
Part of eye:
eyelashes, protect eye from danger and keeps from drying out
Lacrimal glands
part of eye:
secretes a solution (tears) that cleanses and protects the eye as it moistens it and ducts drain excess fluid into the nasolacrimal duct
ciliary and meibomian glands
part of eye:
secretes acidic sweat to kill bacteria,lubricate eyelids, and moisten w oils
Conjunctiva
Part of eye:
transparent mucus membrane that lines the eyelids an the whites of eyes. prevents eye from drying out.
COVERS ENTIRE EYE
sclera
Part of eye:
white, connective tissue- anchors and protects
White part of eye
Cornea
Part of eye:
allows for light to pass through (refracts, or bends light slightly) keeps stuff out of eye
iris
colored part of the eye, involuntary muscles to dilate pupil
pupil
central opening of the iris, lets the light in, the more light the better you see
Regulates amount of light entering the eye
…close vision and bright light:constrict
…distant vision and dim light:dilate
what protects eyes from uv?
Melanin
Inner part of eye
Aqueous humor
-plasma like fluid that fills the anterior segment
-supports,nourishes, and removes wastes
Inner part of eye
Lens
-avascular, transparent, flexible structure that can change shape to allow precise focusing of the light on the retina.
REFRACTS LIGHT GREATLY
…light bends or refracts the light to help it focus on the retina (back of eye) the retina helps us see by sending signals to brain
inner part of eye
Vitreous humor
-jelly like substance behind the lens
-keeps eye from collapsing
(nourish eye and keep from collapsing)
retina
photoreceptors and glial cells capture light and convert it into electrical signals. leave at optic nerve.
photoreception
process where the eye detects light energy
photoreceptors
-modified neurons that structurally resemble tall epithelial cells
-contain light-absorbing molecule called retinal (vitamin A sub)
RODS AND CONES
Rods
-highly sensitive
-night vision/dim light
-Helps with peripheral vision
-help you see in low light, like at night. They don’t see color, but they help you see shapes and movement when it’s dark.
cones
-less sensitive to light
-best adapted to bright light and color vision
ganglion cell axons
-run along the inner surface of retina
-leave eye as the optic nerve
the optic disc
-the site where the optic nerve leaves the eye
-lacks photoreceptors (the blind spot)
-part of your retina where the optic nerve connects to the eye. It’s often called the “blind spot” because it doesn’t have any light-sensitive cells, so you can’t see anything in that spot.
ear- houses two senses
-hearing; interpreted in the auditory cortex of the temporal lobe
-Equilibrium (balance); interpreted in the cerebellum
-receptors are mechanoreceptors
properties of sound
SOUND:created by vibration that cause alternating high and low pressure in the air
FREQUENCY: is the number of sound waves that pass a given point in a given time
AMPLITUDE: the height of sound waves (determines loudness)
Auditory processing
involves perception of pitch, detection of loudness, and localization of sound
outer (external) ear
-Pinna; collects sound
-External auditory canal; channels sound inward
lined w/ skin… cerumen (ear wax) present
ends @ tympanic membrane (eardrum)
middle ear (tympanic cavity)
-two tubes are associated w the inner ear
… the opening from the auditory canal is covered by the tympanic membrane (ear drum)
…the auditory tube connecting the middle ear w the throat (Eustachian tube); allows for equalizing pressure during yawning and swallowing
3 bones of the tympanic cavity
malleus(hammer)
incus(anvil)
stapes(stirrup)
transfer and amplify sound to the inner ear
inner ear (osseous labyrinth)
-boney tubes within the temporal bone
function- helps w hearing and balance
filled with perilymph (fluid)
-sound waves travel through cochlea
-hair cells in the organ of corti move w the fluid
-nerve impulses are sent to the brain for interpretation
cochlea
-Cochlea: converts sound vibrations into nerve signals
-channel new vibrations through perilymph; transfers to organ of corti
organ of corti: contain tiny hair like cells that detect sound
