Sensory System Flashcards
the process by which external energy is received at sensory organs and transduced into electrical signals
sensation
our interpretation of neural signals
perception
3 steps for interpretation of electrical signals by brain
- Physical stimulus
- Transduction
- Perception
4 types of mechanoreceptors
- Touch/Pressue
- Vibration
- Stretch
- Hearing
- Balance
Termoreceptors receive what type of stimulus
temperature
5 types of receptors
- Mechanoreceptors
- Thermoreceptors
- Pain Receptors
- Chemoreceptors
- Photoreceptors
Chemoreceptors detect what two types of sensations
taste and smell
What can alter perception?
pre-existing states
5 types of receptors in the skin
- Unencapsulated dendritic endings
- Merkel Disks
- Meissner’s corpuscles
- Ruffini endings
- Pacinian corpuscles
naked endings of sensory neurons around hairs and near the skin surface that signal pain, light pressure and changes in temperature
unencapsulated dendritic endings
modified unencapsulated dendritic endings that detect light touch and pressure
merkel disks
encapsulated touch receptors located close to the skin surface that detect the beginning and end of light pressure touch
meissner’s corpuscles
receptors that respond to continually ongoing pressure on skin
ruffini endings
nerve endings in dermis that respons to either deep pressure or high frequency vibration
pacinian corpuscles
the nerve ending of a pacinian corpuscle is covered by loose layers of
connective tissue
specialized structures for monitering muscle length
muscle spindles
a small bundle of modified skeletal muscle cells located within a skeletal muscle
muscle spindle
ruffini ending indicate
limb position and object shape
ruffini endings respond to
stretch
what speed of adaptation do meissner’s corpuscles have?
rapidly adapting
the semi rigid epthelial cell in skin
merkel disk
nocireceptors are also called
free nerve endings
sounds are waves of
compressed air
both intensity and perceived loudness are related to
the amplitude of sound waves
sound waves are measured in
decibles (dB)
hearing loss can result from exposure to sounds louder than…
85dB
the tone/pitch or a sound is determined by its…
frequency
the number of wave cycles that pass a given point per second
frequency
the outer ear consists of
the pinna and auditory cannal
the auditory canal channels sounds waves into the…
tympanic membrane
another name for the tympanic membrane is
the ear drum
an air-filled chamber within the temporal bone of the skill, bridged by three small bones
the middle ear
the three small bones in the middle ear are called
the malleus (hammer) the incus (anvil) the stapes (stirrup)
the three bones in the ear vibrate when…
sound waves strike and vibrate the tympanic membrane
the stapes, when vibrating, touches a smaller membrane called
the oval window
the vibrating force that concentrates down from the ear drum to the oval window causes
amplification
The air filled middle ear is kept at atmospheric pressure by…
the auditory tube
another word for the auditory tube is called
the eustachian tube
the narrow tube that runs from the middle ear to the throat
eustachian tube
the inner ear sort sounds by tone and converts them into…
impulses
the inner ear consists of
cochlea, vestibular apparatus
the cochlea contains two interconnected outer canals called
the vestibular canal and tympanic canal
the third, close fluid filled space in cochlea is called
the cochlear duct
the base of the cochlear duct is formed by
the basilar membrane
what types of cells are in the basilar membrane?
hair cells
together, hair cells and tectorial membrane in the ear are called
the organ of corti
what does the organ of corti do?
converts pressure waves to action potentials
when sound waves strike the oval window, it generates pressure waves in the watery fluid of the…
vestibular canal
after the cochlea, waves strike another membrane called
the round window
what does the round window do?
bulges in and out in synchronicity with the oval window, reducing some pressure
because hairs in ear are embedded inthe less movable tectorial membrane, vibration of the basilar membrane causes hairs to…
bend
the physical movement of hairs in inner ear causes
the release of more or less neurotransmitter, depending on which way the hairs are bent
the white, tough outer coat of the eye
sclera
the clear layer over the front of the eye
cornea
the fluid that nourishes and cushions the cornea and lens are called
the aqueous humor
the colored, disk shaped muscle that determines how much light enters the eye
iris
the adjustable opening in the center of the iris
pupil
the transparent, flexible structure attached by connective tissue fibres
lens
the ring of circularly arranged smooth muscle attached to the lens
ciliary muscle
the eye is filled with
virteous humor
the layers are the back and sides of the eye
retina
the retina is composed of
photoreceptor cells, neurons, and a few blood vessels
nerve at the back of eyeball that carries information to the thalamus
optic nerve
the central region of the retina where photoreceptor density is the highest
the macula
the area where the axons of the optic nerve and associated blood vessels exit the eye
optic disk
the iris adjusts the amount of light entering the eye with
two sets of smooth muscle
the cornea is responsible for
bending most incoming light
the outermost layer of the retina consists of
pigmented cells that absorb light not captured by photoreceptor cells
the second layer of retina is called
rods and cones
the rods and cones synapse with the third layer of neurons called
bipolar cells
what do bipolar cells do?
process and integrate info and then pass it on to the fourth layer
the innermost layer of the retina consists of
ganglion cells
the long axons of the ganglion cells become
the optic nerve
the flattened disks on rods and cones contain numerous molecules of a particular light sensitive protein callled….
photopigment
when a photopigment is exposed to light energy, what happens?
it changes in shape
the change in photopigment shape causes the photorecpetor to….
close some of its sodium channels and reduce the amount of neurotransmitter that it normally releases
Rods provide vision for…
dim light
between rods and cones, what are more numerous in periphery?
rods
what do we have more of? Rods or cones?
Rods
for near objects, what happens to ciliary muscles?
they contract and get the lens to bulge
to focus on distant objects, what happens to the ciliary muscles?
relax to pull lens and flatten it
term for the adjustment of lens curvature so we can focus on either near or far objects
accomodation
medical term for nearsightedness
myopia
term for farsightedness
hyperopia
the focal plane for hyperopia is where
behind the retina
astigmatisms (blurred vision) are due to
abnormal curvature of either the cornea or the lens
glaucoma causes an increase in
ocular pressure
macular degeneration is caused by
a detached retina
cataracts is caused by
an opaque lens
most of the receptors for taste are located where?
on the edges and front and back of tongue
the small projection on tongue are called
papillae
what are located on the surface of papillae?
taste buds
the chemoreceptors in taste cells are called
tastants
odors are detected by what kind of receptor cells?
olfactory receptor cells
