Nervous System Overview

Question 1

What are the functions of the nervous system?

Answer 1

• Communication
• Regulating internal events
• Organising behaviour (external)
• Information storage (memory)
• Sensations, perceptions, emotions

Question 2

Which cells make up the nervous system?

Answer 2

Neurons and glial cells

Question 3

Which cells are more numerous in the nervous system: glial cells or neurons?

Answer 3

Glial cells

Question 4

What is the role of glial cells?

Answer 4

• Supportive nutritive role
• Responsible for myelin formation
• Schwann cells (peripheral NS)
• Oligodendrocytes (central NS)

Question 5

What is the role of astrocytes?

Answer 5

Nutrition (nutrient supply to neurons in CNS)

Question 6

What is the role of microglia?

Answer 6

Defence role

Phagocytic

Question 7

What is the role of ependymal cells?

Answer 7

Involves in production of CSF (cerebrospinal fluid)

Question 8

What is the role of oligodendrocytes?

Answer 8

Neuronal support and myelin formation in CNS

Question 9

What is the role of Schwann cells?

Answer 9

Neuronal support and myelin formation in PNS

Question 10

Name 5 types of glial cells

Answer 10

• Astrocytes
• Microglia
• Ependymal cells
• Schwann cells
• Oligodendrocytes

Question 11

What are neurons?

Answer 11

• Excitable cells
• Generate and transmit signals
• Make connections through synapses
• Synaptic processing, memory
• Structure is related to function

Question 12

What is the peripheral nervous system composed of?

Answer 12

Spinal nerves, cranial nerves

Question 13

What is the central nervous system composed of?

Answer 13

Brain and spinal cord

Question 14

Where do sensory pathways bring information from/to?

Answer 14

From periphery to CNS via afferent nerves

Question 15

What are the 2 subtypes of afferent nerves?

Answer 15

Somatic afferents (conscious info), visceral afferents (non-conscious info)

Question 16

Where do motor pathways bring information from/to?

Answer 16

From CNS to the periphery via efferent nerves

Question 17

What are the 2 subtypes of efferent nerves?

Answer 17

Somatic efferent and visceral efferents (autonomic nervous system)

Question 18

How many pairs of spinal cord nerves are there?

Answer 18

31

Question 19

What are the 31 pairs of spinal cord nerves (broadly)?

Answer 19

8 Cervical Nerves
12 Thoracic Nerves 
5 Lumbar Nerves 
5 Sacral Nerves 
1 Coccygeal Nerves

Question 20

What type of axons does each spinal cord nerve contain?

Answer 20

Sensory and motor axons

Question 21

Axons of each sensory nerve supply structures in a well-defined part of the body surface. What are these regions termed?

Answer 21

Dermatomes

Question 22

What is a myotome?

Answer 22

A group of muscles that a single spinal nerve innervates

Question 23

Motor axons supply blocks of muscle called ________

Answer 23

Myotomes

Question 24

What is a nerve plexus?

Answer 24

A plexus of intersecting nerves

Composed of afferent and efferent fibres

Question 25

How many pairs of cranial nerves are there?

Answer 25

12

Question 26

What do cranial nerves do?

Answer 26

Provide sensory and motor nerve supply to head and neck structures

Question 27

Where is the vagus nerve (CN X) distributed?

Answer 27

To the trunk

Question 28

Which cranial nerves contain autonomic nerve fibres?

Answer 28

CN 3, 7, 9 10

Question 29

Which 3 layers of a nerve cell does anaesthetic need to penetrate?

Answer 29

Epineurium, perineurium, endoneurium

Question 30

Lidocaine is amphiphilic. What does this mean?

Answer 30

Has both hydrophilic and hydrophobic parts

Question 31

What are afferent signals in somatic nerves associated with?

Answer 31

Sensations/perceptions

Question 32

What do 'somatic' efferents control?

Answer 32

Voluntary muscle

Question 33

What do 'visceral' efferents constitute?

Answer 33

The automatic nervous system (smooth muscle, cardiac muscle, some glands)

Question 34

Describe A-alpha neurons

Answer 34

Myelinated Some sensory neurons Motor neurons

Question 35

Describe A-beta neurons

Answer 35

Myelinated | Sensory neurons

Question 36

Describe A-gamma neurons

Answer 36

Myelinated | A special form of motor neuron

Question 37

Describe A-delta neurons

Answer 37

Sensory neurons

Question 38

Describe C neurons

Answer 38

Sensory neurons | Some autonomic nerves

Question 39

Why is local anaesthetic often used in conjunction with a vasoconstrictor?

Answer 39

Local anaesthetic works for a longer time if you reduce the amount of blood vessels in that area