Spinal Nerves 2022

Question 1

what part of the body does the somatic nervous system innervate

Answer 1

body wall

Question 2

what part of the body does the visceral nervous system innervate

Answer 2

internal organs

Question 3

whats another word for sensory nervous system

Answer 3

afferent

Question 4

whats another word for motor nervous system

Answer 4

efferent

Question 5

what is a ganglion

Answer 5

a collection of neuron cell bodies outside the CNS

Question 6

what direction does information travel in sensory innervation

Answer 6

from the environment to the CNS

Question 7

what direction does motor innervation information travel

Answer 7

from the CNS to the muscle and glands

Question 8

what is the target tissue for somatic motor innervation

Answer 8

skeletal muscle

Question 9

is somatic motor innervation conscious or unconsious

Answer 9

conscious

Question 10

how many neurons connect the CNS to the target muscle in somatic motor innervation

Answer 10

one

Question 11

is somatic sensory innervation conscious or unconscious

Answer 11

conscious

Question 12

how many neurons connect somatic sensory innervation to the CNS

Answer 12

one

Question 13

whats an example of somatic sensory stimuli

Answer 13

• pain from cutting, tearing, crushing, inflammation or burning
• temperature
• touch
• pressure
• virbration

Question 14

how many spinal nerves are there and how many are in each segment

Answer 14

31 pairs.

• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 1 coccygeal

Question 15

what does the paraxial mesoderm give rise to

Answer 15

bone, skeletal muscle, and dermis below the head

Question 16

how are somites formed

Answer 16

`paraxial mesoderm gets pinched off

Question 17

how many pairs of somites are there and how many are in each segment

Answer 17

37 pairs

• 4 occipital
• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 3 coccygeal

Question 18

what 2 tissues do somites divide into

Answer 18

dermamyotome and sclerotone

Question 19

what does the dermamyotome split into

Answer 19

epaxial dermamyotome and hypaxial dermamyotome

Question 20

what separates the epaxial dermamyotome and the hypaxial dermamyotome

Answer 20

thoracolumbar fascia

Question 21

what does the epaxial dermamyotome give rise to

Answer 21

inrinsic deep back muscles and the dermis that covers them

Question 22

what does the hypaxial dermamyotome give rise to

Answer 22

all other skeletal muscle and dermis below the neck, including limbs

Question 23

why do hypaxial and epaxial dermamyotome have different nerve supplies

Answer 23

because of the barrier imposed by the thoracolumbar fascia

Question 24

which spinal nerves do not have somatic motor axons

Answer 24

S5 and Co1

Question 25

where are sympathetic axons found in spinal nerves

Answer 25

in all of them

Question 26

where are parasympathetic axons found in the spinal cord

Answer 26

below the beck only S2-S4

Question 27

why do S5 and Co1 not have somatic motor axons

Answer 27

because somites are so small they dont have much muscle derived from them

Question 28

where are cell bodies located in somatic motor innervation

Answer 28

ventral horn

Question 29

what does each spinal nerve branch into and why does it branch

Answer 29

dorsal ramus and ventral ramus because muscles supplied by a spinal cord segment supply muscle from different embryonic primordia

Question 30

what do dorsal rami supply

Answer 30

intrinsic deep back muscles derived from epaxial dermamyotome

Question 31

what do ventral rami supply

Answer 31

all other skeletal muscles below the head that are derived from hypaxial dermamyotomes

Question 32

where are the cell bodies in somatic sensory innervation pathway located

Answer 32

dorsal root ganglion

Question 32

where are the cell bodies in somatic sensory innervation pathway located

Answer 32

dorsal root ganglion