Topic 19: Nervous System - PNS - Spinal nerves Flashcards
1
Q
How many pairs of spinal nerves do we have?
A
- 31 MIXED nerves
2
Q
Name how many of each spinal nerves we have
A
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccyx
3
Q
Where do these spinal nerves exit?
A
- intervertebral foramina except 1st, which exits between atlas and occipital
4
Q
Each nerve has 2 points of attachment to the spinal cord. Name these attachments
A
- dorsal root
- ventral root
5
Q
What neurons and cell bodies are in the dorsal root?
A
- sensory
- cell bodies in dorsal root ganglia
6
Q
What neurons and cell bodies are in the ventral root?
A
- autonomic and somatic motor neurons
- cell bodies in ventral or lateral horn
7
Q
What is the spinal nerve?
A
- joining of dorsal and ventral roots
8
Q
What does the spinal nerve immediately divide into?
A
branches called rami
9
Q
What are the 3 rami?
A
- dorsal rami
- ventral rami
- rami communicantes
10
Q
what does the dorsal ramus do?
A
- innervates skin and muscles of the back
11
Q
What does the ventral ramus form?
A
- thoracic nerves (T2-T12) or further branch and join up, forming nerve plexuses (nerve network)
12
Q
Diagram of spinal nerve plexuses
A
13
Q
What is the function of the rami communicantes?
A
- connects ventral ramus (spinal nerve) to sympathetic trunk
14
Q
What does the rami communicantes contain?
A
- autonomic nerve fibres (neurons)
