Peripheral Nervous System

Question 1

What does the CNS consist of?

Answer 1

brain

spinal cord

Question 2

What does the PNS consist of?

Answer 2

cranial nerves
spinal nerves
ganglia

Question 3

collection of neuron cell bodies OUTSIDE the CNS

Answer 3

ganglion

Question 4

How many pairs of cranial nerves are there?

Answer 4

12

Question 5

How many pairs of spinal nerves are there?

Answer 5

31

Question 6

Where does information flow in sensory (afferent) innervation?

Answer 6

environment –> CNS

Question 7

Where does information flow in motor (efferent) innervation?

Answer 7

CNS –> muscle and glands

Question 8

Which part of a neuron carries impulse out to muscle to contract?

Answer 8

axon

Question 9

Which neuron has a cell body between 2 axon ends and forms a ganglion with other cell bodies?

Answer 9

sensory neuron

Question 10

Somatic innervation concerns the ___ ___.

Answer 10

body wall

Question 11

2 examples of somatic innervation

Answer 11

skeletal muscle
skin
bone

Question 12

Visceral innervation concerns the ____ _____.

Answer 12

internal organs

Question 13

3 examples of visceral innervation

Answer 13

heart
lungs
GI tract

Question 14

T/F: Functional dichotomies of the nervous system do not intersect.

Answer 14

false: they do intersect

Question 15

T/F: Both somatic and visceral innervation contain sensory AND motor neurons.

Answer 15

TRUE
body wall: (somatic sensory + somatic motor)
internal organs: (visceral sensory + visceral motor)

Question 16

What is the target tissue of somatic motor innervation?

Answer 16

skeletal muscle (diaphragm included)

Question 17

Is somatic motor innervation conscious/unconscious?

Answer 17

conscious (voluntary)

Question 18

How many neurons in somatic motor innervation and what do they connect?

Answer 18

one

CNS –> target muscle

Question 19

Somatic sensory innervation carries information about the internal/external environment?

Answer 19

external

Question 20

Where does somatic sensory innervation carry information from?

Answer 20

skin

musculoskeletal system

Question 21

Is somatic sensory innervation conscious/unconscious?

Answer 21

conscious

Question 22

How many neurons in somatic sensory innervation and what do they connect?

Answer 22

one

site of stimulus –> CNS

Question 23

Name the 5 examples of somatic sensory stimuli:

Answer 23

• pain (cutting, tearing, crushing, inflammation, burning-heat/chemical)
• temperature
• touch
• pressure
• vibration

STIMULI THAT CAN BE FELT BY THE SKIN

Question 24

Division of the mesoderm that gives rise to bone, skeletal muscle, and dermis

Answer 24

paraxial mesoderm

Question 25

How many pairs of somites does the paraxial mesoderm have?

Answer 25

37 pairs of somites

Question 26

``` 37 pairs of somites: __ occipital __ cervical __ thoracic __ lumbar __ sacral __ coccygeal ```

Answer 26

``` 4 8 12 5 5 3 ```

Question 27

How many pairs of somitomeres are there?

Answer 27

7

Question 28

What does the epaxial dermamyotome give rise to?

Answer 28

intrinsic (deep) back muscles and dermis that covers them | NOTHING ELSE

Question 29

What does the hypaxial dermamyotome give rise to?

Answer 29

all other skeletal muscles and dermis below the neck including limbs

Question 30

What is required for each individual somite? (2)

Answer 30

innervation | blood supply

Question 31

Do epaxial and hypaxial dermamyotomes have combined/separate innervation and blood supplies?

Answer 31

separate

Question 32

In what way is the spinal cord segmented?

Answer 32

functionally

Question 33

What does each level of the spinal cord have that serves the tissues that originate from the same level, including the somite pair?

Answer 33

cell bodies

Question 34

Each somite pair is associated with what?

Answer 34

pair of spinal nerves

Question 35

How are spinal nerves numbered?

Answer 35

superior --> inferior

Question 36

What are the names and numbers of the 31 pairs of spinal nerves?

Answer 36

``` 8 cervical (C1-C8) 12 thoracic (T1-T12) 5 lumbar (L1-L5) 5 sacral (S1-S5; S5= dermatome only) 1 coccygeal (Co1 = dermatome only) ```

Question 37

What components do all spinal nerves have?

Answer 37

somatic sensory components somatic motor components (not S5 or Co1) carry sympathetic axons

Question 38

In which spinal nerves are parasympathetics found?

Answer 38

S2-S4

Question 39

What are the 2 spinal nerves that do not have sensory motor components?

Answer 39

S5 | Co1

Question 40

In somatic motor innervation to the body wall, there is a __-neuron pathway between the spinal cord and the target, which is _____ _____.

Answer 40

one | skeletal muscle

Question 41

Where are cell bodies located in the spinal cord?

Answer 41

ventral horn (gray matter)

Question 42

How do somatic motor neurons leave the spinal cord?

Answer 42

via VENTRAL ROOTS of spinal nerves

Question 43

Because the muscles supplied by a spinal cord segment supply muscle from different embryonic primordia, each spinal nerve has to branch into a _____ _____ and a _____ _____.

Answer 43

dorsal ramus | ventral ramus

Question 44

Intrinsic (deep) back muscles are derived from ____ dermamyotomes and are supplied by ___ rami; all other skeletal muscles below the head are derived from ____ dermamyotomes and are supplied by ____ rami.

Answer 44

epaxial dorsal hypaxial ventral