FoM:L6 - Somatic Nervous System Flashcards
1
Q
What is a pseudo-unipolar neuron?
A
- looks as if their is 1 pole but has 2
- sensory information
2
Q
What are bipolar neurons?
A
- has 2 poles
- special sensory information (e.g. eyes, ears, nose etc.)
3
Q
What is a multi-polar neuron?
A
- multiple dendrites leading to the cell body, 1 axon away
- motor neuron
4
Q
What are glial cells of the PNS?
A
- support cells for the neuron
- Schwann cells: myelinated (wrapped itself around the axon) and unmyelinated (1+ axons invaginated into cell)
- satellite cells: support cell bodies
5
Q
What are astrocytes?
A
- physical and metabolic support
- blood brain barrier
6
Q
What are oligodendrocytes?
A
- myelination, wrap around axon(s)
- multiple neurons
- NOT unmyelinated
- glial cells of CNS
7
Q
What are ependymal cells?
A
- line ventricles and central canal
- produce and secrete CSF
- absorb CNS = microvilli
- propel CNS = cilia
8
Q
What are microglia?
A
- phagocytotic
- provide defence
- glial cells of CNS
9
Q
Outline the structure of a nerve
A
- endoneurium surrounds individual neurons
- multiple neurons bundled into fascicles, surrounded by perineurium
- multiple fascicles surrounded by epineurium
10
Q
Outline nerve damage
A
PNS
- crushed: if still connected can be regenerated
- severed nerve needs surgical intervention
CNS
- astrocyte proliferation prevents nerve growth and regeneration
11
Q
Outline the structure of spinal nerves
A
- 31 pairs (8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal)
- spinal cord, exit through intervertebral foramina
- cervical and lumbosacral enlargements: nerves extend to limbs
- cauda equina (bundle of nerves)
12
Q
What are the meninges?
A
3 layers
- dura mater: tough outer coat (continuous with epineurium)
- arachnoid mater: pressed against dura due to P from CSF
- pia mater: immediately hugging spinal cord
13
Q
Outline a typical spinal nerve
A
- dorsal root: sensory
- ventral root: motor
- outside of foramen, splits to ventral and dorsal rami
14
Q
A
