Nervous System

Question 1

Describe what white and grey matter are and their distribution within a spinal cord segment

Answer 1

White matter: axons connecting the grey matter (outside)

Grey matter: synapses (inside)

Question 2

What nerves enter/leave each horn of the grey matter?

Answer 2

Dorsal horn: sensory neurone enters
Lateral horn: autonomic neurone leaves
Ventral horn: motor neurone leaves

Question 3

How is the nervous system divided?

Answer 3

Central nervous system (brain and spinal cord - connects signals btw the brain and the PNS)

Peripheral nervous system (spinal nerves):
Somatic (controls voluntary motor and sensory nerves)
Autonomic (controls sympathetic, parasympathetic and enteric nervous system)

Question 4

Where are the preganglionics found in the for the parasympathetic and sympathetic nervous system?

Answer 4

Parasympathetic: S2 - S4 spinal segments and the brain stem (III, VII, IX, X)
Sympathetic: T1 - L2 spinal segments

Question 5

Where do the preganglionics of the parasympathetic and sympathetic synapse?

Answer 5

Parasympathetic: walls of their targets
Sympathetic: sympathetic chain

Question 6

What are the types of glial (nueroglia) cells?

Answer 6

Oligodendrocytes
Schwann cells
Microglia
Astrocytes

Question 7

What are the differences between oligodendrocytes and Schwann cells?

Answer 7

Oligodendrocytes: found in the CNS + can myelinate more than 1 axon
Schwann cells: for;d in the PNS + can myelinate a single axon

Question 8

What is the function of microglia?

Answer 8

Wandering immune cells of the CNS
Have mobile processes that extend into the CNS
When these processes detect pathogens or antigens, they turn into macrophages

Question 9

What is the function of astrocytes?

Answer 9

Extend processes into synapses to take up any excess of neurotransmitter released
Modulate permeability of capillaries; creating a Blood-Brain Barrier which affects the uptake of neurotransmitters and xenobiotics

Question 10

What is the paravertebral ganglia?

Answer 10

Ganglia found on the sympathetic chain where sympathetic preganglionics synapse

Question 11

Which nerves travel down the white and grey ramus?

Answer 11

White ramus: preganglionic sympathetic nerve

Grey ramus: postganglionic sympathetic nerve

Question 12

What are the ways in which preganglionics synapse in the sympathetic chain?

Answer 12

Ascend the chain then synapse
Descend the chain then synapse
Traverse the chain then synapse (in the pre-aortic ganglion)
Synapse at the level of entry (supply dermatomes)

Question 13

What are the major ganglia of the parasympathetic system in the face?

Answer 13

Ciliary
Pterygopalatine
Sub-mandibular
Otic

Question 14

What are the preganglionics and postganglionics of the ciliary ganglion?

Answer 14

Preganglionic: Occulomotor
Postganglionic: eye

Question 15

What are the preganglionics and postganglionics of the pterygopalatine ganglion?

Answer 15

Preganglionic: facial nerve
Postganglionic: lacrimal glands

Question 16

What are the preganglionics and postganglionics of the submandibular ganglion?

Answer 16

Preganglionic: facial nerve
Postganglionic: submandibular and sublingual

Question 17

What are the preganglionics and postganglionics of the otic ganglion?

Answer 17

Preganglionics: glossopharyngeal nerve
Postganglionics: parotid glands

Question 18

How are nerve fibres bundled together?

Answer 18

Nerve fibres surrounded by endoneurium
Nerve fibres bundled into fascicles
Fascicles surrounded by perineurium
Groups of fascicles bundled together to a form spinal nerve
Spinal nerve surrounded by epineurium