lifespan perspective of the sensory system Flashcards
dorsal root ganglion
a collection of cell bodies of the afferent sensory fibers
perception
integration of sensory impressions into psychologically meaningful information
sensory maps
location of sensory receptors in the brain
sensory homunculus
shows somatic sensory projections from the body surface
nociceptors
pain receptors
somatosensory system function
transmit information about the senses to the CNS to regulate behavior
what is the first sensory system to function in utero
touch
when can a fetus respond to touch
7 weeks
when do muscle spindles form
12 weeks in utero
when do golgi tendon organs form
16 weeks in utero
when does cutaneous sensation spread to the whole body
17 weeks in utero
specific touch localization occurs at what age
12-16 months old
when can a child identify objects by touch
5 years old
when does two point discrimination occur in a child
7 years old
when does proprioceptive acuity for movements improve
5-12 years old
when is the sensory system the keenest
late adolescence into early adulthood
what % does reaction time slow down in middle adulthood
20%
what can affect the ability of joint receptors to detect motion
arthritic changes
what is in control of posture, locomotion, balance, and hand function
vision
saccades
quick simultaneous movement of both eyes in the same direction
slow pursuit/tracking
slow smooth eye movements to closely follow a moving object
vesibulo-ocular reflex (VOR)
moving head side to side but keeping eyes in one spot
vergence
moving the eyes simulations in different directions
tracking an object coming to your nose (convergence) vs going away from nose (divergence)
when do eyes form
4 weeks in utero
when does myelination begin
13 weeks in utero
when is reflexive blinking
6 months of gestation
what is the visual acuity at birth
20/800
what is the best distance for fixation in newborns
7-9 inches
what colors are seen at 2 months
red and yellow
when does preference for a colored object occur
3 months
when does full color vision occur
4 months
when does binocular vision begin maturing and when is adult-like vision developed
3-5 months
2 years
when is 20/20 vision achieved by
12 months
when are adult levels of depth perception achieved
12
when does rapid decline of the visual system occur
60-80
when does vision stabilize
40s and 50s
when do cataracts begin to form
over 30
presbyopia develops at age ___
45
decline in the ability to adapt from light to dark environments
40
what % of adults over 65 have cataracts
60%
what % of adults over 75 have macular degeneration
28%
when do vestibular structures begin thickening in utero
week 4
when is the vestibular system completely myelinated
birth
when is the vestibular ocular reflex present by
2 months
when is full maturity of the vestibular system achieved
10-14 years old
when does static balance begin
9-12 years old
when does dynamic balance begin
12 years
when does the vestibular system begin to decline
40s
___% reduction in hair cells and ____% reduction in peripheral nerve fibers in adults over 70
40%
36%
what is the starting position of the functional reach test
arm closest to the wall
feet together
keep shoulders square
what metacarpal is used to measure during functional reach test
third
