Nervous System Anatomy

Question 1

What are ganglia?

Answer 1

Collection of nerve cell bodies

Question 2

Describe the sensory/afferent nervous system

Answer 2

Part of PNS
• Somatosensory- skeletal muscle and skin
• Viscerosensory- homeostatic control of body and gut
• Special sensory- ears, eyes, nose

Question 3

Describe the motor/efferent nervous system

Answer 3

Part of PNS
• Somatomotor- skeletal muscle- voluntary
• Autonomic- smooth muscle- involuntary (parasympathetic, sympathetic, enteric)

Question 4

How many spinal nerves are there and what are they called?

Answer 4

31 pairs
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Question 5

How many cranial nerves are there and what are their names and functions?

Answer 5

I olfactory- sense of smell
II optic- vision
III oculomotor- eye muscles
IV trochlear- 1 eye muscle
V trigeminal
VI abducens- 1 eye muscle
VII facial
VIII vestibulocochlear- balance, hearing
IX glossopharyngeal
X vagus
XI accessory (spinal)
XII hypoglossal

Question 6

Which cranial nerves are sensory and motor?

Answer 6

1,2,8- sensory (smell, balance+hearing)

3,4,6- motor (eyes)

Question 7

What makes up grey matter?

Answer 7

Neuron cell bodies

Question 8

What makes up white matter?

Answer 8

Acorns connecting spinal cord to brain

Question 9

What do the dorsal and central root each do?

Answer 9

Dorsal root- carries sensory info to brain

Central root- carries motor info away from brain

Question 10

What is the dorsal root ganglion made up of?

Answer 10

Cell bodies of afferent sensory neurons

Question 11

Describe afferent sensory neurons

Answer 11

• Cell bodies located in dorsal root ganglion
• Single axon divides into peripheral and central branches
• Peripheral branch- conveys info from sensory receptors towards ganglion and CNS via mixed peripheral nerves
• Central branch- conveys info towards CNS via dorsal root

Question 12

How do neurons vary between each other?

Answer 12

• Different neurons for different temperatures
• Different ganglia associated with different parts of the body
• Pain neurons more dorsal, touch more ventral

Question 13

What do proprioreceptors do?

Answer 13

Give info about muscle tension

Question 14

Describe the autonomic nervous system

Answer 14

Part of PNS and motor
• Homeostatic control and gut
• sympathetic, parasympathetic, enteric

Question 15

How does the ratio of white to grey matter change in the spinal cord?

Answer 15

Increases from caudal to rostral

White matter increases from low to high