Somatic nervous System

Question 1

Name the three main anatomical features of a neuron

Answer 1

cell body, dendrites & axons

Question 2

Name the three different types of neuron

Answer 2

1. bipolar
2. Multipolar
3. Pseudo unipolar

Question 3

What is the difference between a bipolar, unipolar & pseudo unipolar neuron?

Answer 3

Bipolar- has a single axon at both sides of the cell body

multipolar- has many dendrites and a long axon

Pseudounipolar- has a single axon which exits the soma (cell body) and splits off into banches

Question 4

What is the most common type of neuron?

Answer 4

Multipolar

Question 5

Where in the body would you find pseudo unipolar neutrons?

Answer 5

Sensory ganglia of cranial and spinal nerves

Question 6

What kind of nerve cells have a myelin sheath?

Answer 6

A myelin sheath is found on neurons of the CNS and PNS

Question 7

Name the cells that make myelin in the PNS and CNS

Answer 7

Myelin is secreted by Schwann cells (glial cells) around some axons in the peripheral nervous system and by oligodendrocytes in the central nervous system

Question 8

What is myelin made up of?

Answer 8

Myelin is a protein and lipid substance

Question 9

What is the function of myelin?

Answer 9

Myelin increased velocity of impulse conduction (insulation)

Question 10

Name the three coverings of peripheral spinal nerves and which part of the muscle they cover

Answer 10

1. Epineurium (thick outer layer containing multiple nerve fascicles
2. Perineurium (Covers individual nerve fascicles)
3. Endoneurium (covers individual, myelinated nerves)

Question 11

What name is given to blood vessels which surround nerves

Answer 11

vasa nervorum

Question 12

What is a dermatome?

Answer 12

Dermatome= an area of skin supplied by a single spinal nerve

Question 13

What is a myotome?

Answer 13

Myotome= Part of a muscle supplied by a single spinal nerve

Question 14

What is a motor end plate?

Answer 14

Motor end plate=- The area that encompasses the end of the axon, the neuromuscular junction and the localised muscle tissue

Question 15

What actions are the somatic nervous system responsible for?

Answer 15

• Somatic nervous system is responsible for general senses and voluntary movement (pain, heat, touch, proprioception).
• Stimuli are received at the periphery and taken to the CNS to be processed.

Question 16

How many spinal nerves are there?

Answer 16

31 spinal nerves and 12 cranial nerves

Question 17

all spinal nerves have a _______ and a _______ component.

Answer 17

All spinal nerves have a sensory and a motor component.

Question 18

Spinal nerves that leave the spinal cord via the dorsal root and pass through the dorsal root ganglion innervate the _________ surfaces of the body

Answer 18

Spinal nerves that leave the spinal cord via the dorsal root and pass through the dorsal root ganglion innervate the posterior surfaces of the body. (e.g. the back, lower surface of the arm and back of the legs)

Question 19

Spinal nerves that leave the spinal cord via the ventral root innervate the ______ surfaces of the body

Answer 19

Spinal nerves that leave the spinal cord via the ventral root innervate the anterior surfaces of the body (e.g. front of the torso, top surfaces of the arm, front of the legs)

Question 20

Name the test that is used to assess the function of the quadriceps

Answer 20

Knee jerk

Question 21

Which nerve is damaged in patients suffering from a wrist drop

Answer 21

The radial nerve