Nerves Revised

Question 1

Where do somatic nerves arise from?

Answer 1

Spinal cord

Question 2

How do somatic nerves arise from the spinal cord?

Answer 2

Via sensory dorsal root and motor ventral root

Question 3

Where would you find a mixed spinal nerve?

Answer 3

Intervertebral foramen

Question 4

What are the two components of a mixed nerve?

Answer 4

Motor and sensory nerve fibres

Question 5

What happens after the mixed spinal nerve leaves the intervertebral foramen?

Answer 5

It branches into dorsal and ventral rami

Question 6

Where does the dorsal ramus supply?

Answer 6

Posterior trunk

Question 7

Where does the ventral ramus supply?

Answer 7

Anterolateral trunk and the limbs

Question 8

What does the dorsal root carry?

Answer 8

Sensory fibres

Question 9

What does the motor root carry?

Answer 9

Motor fibres

Question 10

What does the ventral rami carry?

Answer 10

Mixed motor and sensory fibres

Question 11

What does the motor rami carry?

Answer 11

Mixed motor and sensory fibres

Question 12

If the anterior horn of the spinal cord was damaged, which part of the body would be affected?

Answer 12

Anterolateral trunk
Limbs

Question 13

If the posterior horn of the spinal cord was damaged, which part of the body would be affected?

Answer 13

Posterior trunk

Question 14

If the dorsal root of the spinal cord was damaged, which part of the body would be affected?

Answer 14

Posterior trunk

Question 15

If the ventral root of the spinal cord was damaged, which part of the body would be affected?

Answer 15

Anterolateral trunk
Limbs

Question 16

If the anterior ramus of the spinal cord was damaged, which part of the body would be affected?

Answer 16

Anterolateral trunk
Posterior trunk
Limbs

Question 17

If the posterior ramus of the spinal cord was damaged, which part of the body would be affected?

Answer 17

Anterolateral trunk
Posterior trunk
Limbs

Question 18

Give an example of a muscle which the dorsal ramus can supply

Answer 18

Erector Spinae

Question 19

Given an example of a muscle which the ventral ramus can supply

Answer 19

Intercostal muscles
Abdominal wall

Question 20

What is cutaneous innervation?

Answer 20

An area of skin which is supplied by a specific cutaneous nerve

Question 21

What does a cutaneous nerve contain?

Answer 21

Nerve fibres from several spinal nerves

Question 22

How does a dermatome differ to a cutaneous nerve?

Answer 22

Dermatome is an area of skin supplied by one spinal nerve.
A cutaneous nerve can consist of fibres from many different spinal nerves.

Question 23

Give an example of one area where the cutaneous nerves and dermatomes are the same.

Answer 23

Thorax
Abdomen

Question 24

Where in the body do the cutaneous nerves and dermatomes differ?

Answer 24

Limbs

Question 25

Which type of innervation is more specific-dermatome or cutaneous nerve

Answer 25

Dermatome

Question 26

Where does the lateral antebrachial cutaneous nerve supply?

Answer 26

Lateral side of the forearm

Question 27

Which level does the spinal nerves of the lateral antebrachial cutaneous nerve arise from?

Answer 27

C5-6

Question 28

Where does the radial dorsal antebrachial cutaneous nerve supply?

Answer 28

Lateral side of the arm

Question 29

Which level does the spinal nerves of the radial dorsal antebrachial cutaneous nerve arise from?

Answer 29

C5-6

Question 30

Which joint occurs in the midline of the trunk at dermatome T2?

Answer 30

Sternomanubrial joint

Question 31

What surface feature is present at dermatome T4?

Answer 31

Nipples

Question 32

What surface feature is present at dermatome T10?

Answer 32

Umbilicus (belly button)

Question 33

In which region is dermatome L1 found?

Answer 33

Inguinal region

Question 34

What is the fatty white substance which surrounds the axon of some nerve cells?

Answer 34

Myelin

Question 35

Which cells secrete myelin?

Answer 35

Schwann cells

Question 36

What is the function of myelin?

Answer 36

Forms an electrically insulating layer

Question 37

What forms a layer around a myelin sheath for each nerve fibre?

Answer 37

Endoneurium

Question 38

What is the endoneurium composed of?

Answer 38

Thin layer of connective tissue

Question 39

What surrounds each fascicle of nerve fibres?

Answer 39

Perineurium

Question 40

In a nerve is big enough, what surrounds it?

Answer 40

Epineurium

Question 41

Name the four components of a nerve