Spinal Nerve And Somatic Plexuses

Question 1

Adult spinal cord ends at :

Answer 1

L4-L5

Question 2

End of cord is called

Answer 2

Conus medullaris

Question 3

Cauda equina

Answer 3

Spinal nerve roots descending to exit as lumbar and sacral nerves

Question 4

What is in the inner gray matter

Answer 4

Cell bodies of neurons and glial cells

Question 5

Outer white matter

Answer 5

Myelinated axons

Question 6

What is the lateral grey horn primarily involved with

Answer 6

Sympathetic motor division

Question 7

At how many levels is the lateral fret column present

Answer 7

17
T1-L2 - sympathetic outflow
S2-S4- parasympathetic outflow

Question 8

Where does C1 to C7 exit

Answer 8

Above the same number vertebra

Question 9

Where does C8 exit

Answer 9

Above the T1 vertebra

Question 10

Where does T1 till the end of the cord exit

Answer 10

Exit from spinal canal through the invertebral foramen below the same number vertebra

Question 11

Dermatome

Answer 11

An area of skin innervated by a single spinal nerve

Question 12

Dermatome map - C5

Answer 12

Shoulder

Question 13

Dermatome map -C6

Answer 13

Thumb

Question 14

Dermatome map -C8

Answer 14

Pinky finger

Question 15

Dermatome map -T4

Answer 15

Nipple

Question 16

Dermatome map - tip of xiphoid process innervated by

Answer 16

T7

Question 17

Dermatome map -T10

Answer 17

Umbilicus

Question 18

Dermatome map -L1

Answer 18

Inguinal region

Question 19

Dermatome map - L4

Answer 19

Great toe

Question 20

Dermatome map -S1

Answer 20

Little toe

Question 21

Dermatome map -S2,3,4

Answer 21

Perineum

Question 22

How many spinal nerves need to be damaged for sensory loss to occur and why ?

Answer 22

Two or more (because of overlap of adjacent spinal nerves )

Question 23

Dermatomes - where does herpes zoster (shingles ) show up

Answer 23

Any root ganglion

Question 24

Ventral Motor neuroblast comes from ?

Answer 24

Basal plate of intermediate layer

Question 25

Ventral Motor neuroblast forms

Answer 25

Somatic motor neuron

Question 26

Lateral Motor neuroblast comes from

Answer 26

Intermediate basal layer

Question 27

Lateral Motor neuroblast from basal plate of intermediate layer forms

Answer 27

Visceral motor neuron (preganglionic sympathetic )

Question 28

Lateral motor neuroblast from the neural crest forms

Answer 28

Visceral motor neuron (post ganglionic sympathetic) in sympathetic chain ganglion

Question 29

Sensory neuroblast in DRG form

Answer 29

Primary sensory nerve

Question 30

What is a myotome

Answer 30

Region of skeletal muscle innervated by a single nerve or spinal cord level

Question 31

What do somatic plexuses innervate

Answer 31

Body wall structures

Question 32

What do visceral plexuses innervate

Answer 32

Organs and glands

Question 33

Somatic nerve plexi consists of :

Answer 33

Cervical , brachial , lumbar and sacral plexus

Question 34

Dorsal rami

Answer 34

Supplies intrinsic back muscles (motor )

Skin over that area (sensory )

Question 35

Ventral Ramus

Answer 35

Supplies all other muscle (not back ) -motor

And skin over that area -sensory