Lecture 3 Flashcards
Sensory
What is the order in which the events in the sensory system occur?
receptors, sensory pathways, central nervous system, motor system
What are the two types of receptors?
1) Nerve cell
2) specialized epithelial cell
sensory pathways describe the _________ and _________ of the sensory stimulus
type and location in the brain (ex: spinoreticular tract)
What is a dorsal root ganglion?
a collection of cell bodies of the afferent sensory fibers
Which functions do the dorsal roots contain?
sensory fibers from the skin, subcutaneous and deep tissues, and viscera
cutaneous, joint, and visceral afferents are composed of ___________ (mylelinated/unmyelinated)
myelinated (conduction is faster)
What is perception?
the integration of sensory impressions into psychologically meaningful information
What is sensory integration?
The ability to use sensory information efficiently EX: combining several sensory inputs to produce a desired movement
What systems are involved in stable standing balance?
somatosensory system (proprioception), vision, and vestibular
What are the three types of receptors in the somatosensory system and what are they responsible for?
1) mechanoreceptors (touch, pressure, vibrator, proprioception)
2) thermoreceptors (hot and cold)
3) nociceptors (pain)
what is exteroception?
the cutaneous sensation of touch from specialized epithelial cells (somatosensory system)
interoception
perception of sensation from inside the body (heartrate, respiratory, and GI)
proprioception
perception of one’s body in space
what is the order of sensory system development in prenatal?
touch, vestibular, smell, hearing, vision, taste, proprioception
when does a fetus respond to touch around mouth?
7 weeks
When are the muscle spindles formed in a fetus?
12 weeks
when are golgi tendon organs formed?
16 weeks
When does cutaneous sensation spread to the entire body?
17 weeks
What maturational changes occur to the somatosensory system throughout childhood
- increased nerve conduction velocity
- redistribution of axon branching
- increased synaptic efficiency
Which reflex is an example of touch developing in infancy in childhood?
rooting reflex (used to find food)
when does specific touch localization occur in infancy / childhood?
12-16 months
when are infants/children able to identify objects by touch?
5 years
when does two-point discrimination develop in infants / children?
7 years
What is the earliest muscle spindles mature?
3 years old
what is an example of how proprioception is used in infants very early after birth?
imitation, reaching, and locomotion
When does proprioceptive acuity for movments improve in infants and children?
between age 5-12
when is the sensory system keenest?
late adolescence into early adulthood
What happens to sensory function in adulthood?
It begins to decline (specifically in middle age)