Chapter 13

Question 1

Nonencapsulated (free) nerve ending receptors

Answer 1

everywhere in body- adbundant in epi c.t.
thermoreceptors, and nociceptors
tactile discs- light touch receptors
hair follicle receptors- detect bending od hairs. light touch receptors

Question 2

Encapsulated dendritic endings - most are mechanoreceptors

Answer 2

tactile corpuscles- in dermal papillae . discriminative touch
lamerllar corpuscles- deep in dermirs. deep pressure
bulbous corsuples (ruffini)- -dermins/hypo similar to tendon (stretch)
muscle spindles - proprio’s that respond to muscle stretch
(golgi) tendon- detect stretch
joint kinesthetic receptors- monitor joint position/motion

Question 3

somatosensory system gets input from receptors in body walls and limbs. explain the 3 main levels of processing in this sys

Answer 3

1. receptor lvl- sensor receptors 2. circuit level- ascending pathways 3. perceptual lvl- neuron processing in cortical sensory areas

Question 4

Neural processing at receptor levl

Answer 4

stimulus-> GP in afferent neuron -> AP at first mylein gap

Question 5

sensory recepots can adapt to unchaning stimuls and AP declines. name fast adapting receptors and slow (non) adapting

Answer 5

fast- touch/smell receptors

slow (non)- interoceptors/prioprioceptors and pain receptors

Question 6

explain what happens at perecpetual level of neural processing

Answer 6

thalamus projects fivers to cerebral cortex- somatosensory (in post central gyrus) and sensory association areas
perception takes pace by determining location and magnitude of stimuli

Question 7

what fibers are associated with sharp pain? burning pain?

Answer 7

sharp- small mylein fibers

burning- small unmylein

Question 8

what is the pathway of pain perception?

Answer 8

fibers (myelin/nonmyelin)-> release glutamate and substance P -> activating second-order sensory neurons -> spinothalamic pathways

Question 9

explain the regeneration of nerve fibers in peripheral

Answer 9

if soma of damaged neuron is intact - regeneration can happen
1. axons becoming fragmented @ injury site 2. macrophages clean out debris 3. axon sprouts/filaments grow through a regeneration tube 4. axon regeneration and new myeline forms

Question 10

spinal nerves have 2 roots - explain ventral and dorsal roots

Answer 10

ventral r.- has motor (efferent) fibers that innervate skeletal
Dorsalr. has sensory (afferent) fibers

Question 11

what does the dorsal root ganglion have?

Answer 11

cell bodies of sensory fibers

Question 12

spinal nerves are short, when they emerge from foramen they divide into rami - explain dorsal, ventral ramus

Answer 12

dorsal rami supply- skin and muscles of dorsal trunk (posterior)
ventral- supply rest of trunk and limbs (intercostal nerve in thoracic region only)

Question 13

rami communicators

Answer 13

have autonomic nerve fibers (sympatheic) attach to base of ventral rami of thoracic spinal nerves

Question 14

rami vs. roots

Answer 14

1. roots lie medial to and for the spinal nerves. each root is either sensory or motor
2. rami lie distal to and are lateral branches of spinal nerves. carry sensory and motor as well

Question 15

what part forms the nerve plexus?

Answer 15

ONLY ventral rami

Question 16

lumbar plexus is in which muscle and what is the major nerve?

Answer 16

psoas major

femoral nerve

Question 17

what is dermatome?

Answer 17

area of skin that is innervated by cutaneous branches of single spinal nerve.

Question 18

5 parts of reflex arc pathway

Answer 18

1. receptor: site of stimulation 2. sensory neuron : transmit info to CNS 3. Integration center: can be monosynpathic of poly 4: motor neuron: conduct efferent impulse fro integration 5. effector: muscle fibers or gland cells repsond

Question 19

stretch and tedon reflexes help with coordination of muscle activity. which sensory receptors activate them? and how?

Answer 19

Proprioceptors: muscle spindles - activated by stretch

and tendon organs - tension in muscles and tendons

Question 20

Stretch reflex is?

Answer 20

monosynap and ipsilateral

Question 21

tendon reflex is?

Answer 21

poly and ipsilateral