nervous system; PNS

Question 1

the PNS consists of

Answer 1

nerves extending from the brain and spinal cord. cranial and spinal nerves
-link all of the regions from the body to the CNS
-ganglia

Question 2

ganglia

Answer 2

cluster of cell bodies of neurons

Question 3

nerve fiber:

Answer 3

an axon, its neurolemma, and its surrounding endoneurial connective tissue

Question 4

neurolemma

Answer 4

consists of cell membranes of schwann cells that surround the axon, separating it from other axons
-two types
-myelinated and unmyelinated

Question 5

Schwann cells

Answer 5

myelin sheath producing cells

Question 6

what does a nerve consist of

Answer 6

-bundle of fibers or fascicles
-the CT coverings that surround and bind the fibers or fascicles
-the blood vessels that nourish the nerve fibers and their coverings

Question 7

what are the three CT coverings around nerves

Answer 7

1. endoneurium
2. perineurium
3. epineurium

Question 8

1. endoneurorium

Answer 8

a delicate CT immediately surrounding the neurolemma cells and axons

Question 9

2. perinuerium

Answer 9

dense connective tissues that encloses the fascicle; providing an effective barrier against protection of a foreign body

Question 10

3. epineurium

Answer 10

thick CT sheath that surround and encloses a bundle of fascicles. it forms the outermost covering of the nerve.

Question 11

describe the sensory and motor division of the PNS

Answer 11

-sensory (afferent): signals are picked by sensory receptors
-motor (efferent) signals are carried away from the CNS

Question 12

describe the structures that make up a spinal nerve

Answer 12

1. rootlets spinal nerves arise rootlets. There are two: ventral (motor) and dorsal (sensory)
2. ventral and dorsal nerve root
   3.mix at spinal nerve
3. dorsal and ventral rami.

Question 13

how many spinal nerves are there

Answer 13

31 pairs

Question 14

what are the regional divisions of the PNS

Answer 14

-somatic
-visceral

Question 15

what are the subdivisons of the PNS

Answer 15

-sensory: somatic and visceral
-motor: somatic and visceral (ANS)

Question 16

describe sensory somatic division

Answer 16

general: touch, pain , vibration, pressure, ant temp
-proprioreception: a sense that detects the amount of change in muscles,
-special somatic senses: hearing, equilibrium, and vision

Question 17

describe sensory visceral division

Answer 17

general: stretch, pain , temp, nausea, and hunger
special: taste and smell. chemical senses with sensory receptors in oral and nasal cavities

Question 18

motor somatic division

Answer 18

signals the contraction of skeletal muscles
-under voluntary control

Question 19

motor visceral division

Answer 19

regulates the contraction of smooth and cardiac muscle, controls the secretion of glands
-ANS
-involuntary

Question 20

what is a nerve plexus and the regions

Answer 20

network of nerves, form a new set of PNS nerves. allow room for excpetions.
-cervical, brachial, sacral, and lumbar region

Question 21

dermatome

Answer 21

area of skin innervated by sensory fibers of one spinal nerve

Question 22

myotome:

Answer 22

muscle mass recieving innervation from fibers of one spinal nerve