Neurology: Anatomy - Introduction to the nervous system

Question 1

How can the nervous system be divided in terms of its function and structure?

Answer 1

Structural division: central vs peripheral NS
Functional division: somatic vs autonomic NS

Question 2

What are the two main cell types in the nervous system?

Answer 2

Neurons
Neuroglia

Question 3

Give 4 examples of neuroglia in the CNS

Answer 3

Oligodendroglia
Astrocytes
Ependymal cells
Microglia

Question 4

Give 2 examples of neuroglia in the PNS

Answer 4

Satellite cells around neurons in the spinal (posterior root) and autonomic ganglia
Schwann (neurolemma) cells

Question 5

What are the two main types of neuron?

Answer 5

Multipolar motor
Pseudounipolar sensory

Question 6

What are the three main structural components of a neuron?

Answer 6

Cell body
Dendrites: carry impulses to the cell body
Axons: carry impulses away from the cell body

Question 7

Compare and contrast the structure and function of multipolar and pseudounipolary neurons

Answer 7

1. Multipolar neurons:
   - Most common type
   - Motor
   - Two or more dendrites, single axon which may have one or more collateral branches
2. Pseudounipolar neurons:
   - Sensory
   - Short, apparently single (but actually double) process extending from the cell body, which separates into a peripheral process and conducts impulses from the receptor organ (e.g. touch, pain, or temperature sensors in the skin) toward the cell body (i.e. the dendrite)
   - Central process that continues from the cell body into the CNS (i.e. the axon)
   - Cell bodies are located outside the CNS in sensory ganglia and are therefore part of the PNS

Question 8

What is a collection of nerve cell bodies called in the CNS vs PNS?

Answer 8

CNS: nucleus
PNS: ganglion (even if solitary nerve cell body)

Question 9

What is a nerve fibre bundle called in the CNS vs PNS?

Answer 9

CNS: tract
PNS: nerve (includes surrounding connective tissue and vaso nervorum)