session 9-nerves

Question 1

All neurones have 1 axon. Neurones with multiple dendrites are alled…

Answer 1

multipolar

Question 2

All neurones have 1 axon. Neurones with 1 dendrite and axon are called…

Answer 2

bipolar (rare, mostly in retina)

Question 3

Neurones with no dendrites and just one axon are called….

Answer 3

unipolar

Question 4

The spinal cord consists of white and grey matter. What does each one hold?

Answer 4

grey=cell bodies, synapses,dendrons, axon terminals

white=axon/nerve fibres

Question 5

what do glia cells do and give some examples of types of glial cells.

Answer 5

• maintain myelinated coating of neurone

- oligodendrocytes, satellite cells (surrounds ganglion cell),schwann cells

Question 6

does the autonomic (involuntary) nervous system contain myelinated or unmyelinated neurones and where?

Answer 6

-both
unmyelinated (peripheral NS)
myelinated (CNS)

Question 7

does the somatic (voluntary) NS contain myelinated or unmyelinated neurones?

Answer 7

ALL myelinated (faster action potentials)

Question 8

what happens in multiple sclerosis?

Answer 8

myelin sheath is destructively removed from axon and replaced by scar tissue
conduction velocity slows down and saltatory propagation is impaired

Question 9

why don’t Schwann cells conduct electricity?

Answer 9

high lipid content

Question 10

what is the function of astrocytes? CNS,PNS or both?

Answer 10

assist in transfer of nutrients and waste between blood brain barrier
CNS

Question 11

what is the function of oligodendrocytes? CNS,PNS or both?

Answer 11

myelination CNS

Question 12

what is the function of microglia? CNS,PNS or both?

Answer 12

immune and inflammatory functions BOTH

Question 13

what is the function of Schwann cells? CNS,PNS or both?

Answer 13

myelination PNS

Question 14

what is the difference between Schwann cell and oligodendrocyte myelination?

Answer 14

each Schwann cell only myelinates one axon, oligodendrocytes can myelinate up to 50 per cell

Question 15

what is the role of satellite cells? CNS,PNS or both?

Answer 15

physical support of peripheral neurones

Question 16

define ganglion

Answer 16

group of nerve cell bodies forming a nerve centre especially near the brain and CNS

Question 17

In the sympathetic NS, which ganglionic nerve fibes are short and which are long? (opposite for parasympathetic NS)

Answer 17

pre ganglionic=short

post ganglionic=long

Question 18

a nerve’s structure is very similar to a muscle. What are the 2 differences regarding the names of structures and the smallest unit of structure?

Answer 18

• endo,peri,epiNEURIUM
• smallest structure in nerves is the axon which is surrounded by the endoneurium..however in muscle, many myofibrils make up muscle cells/fibres and a bundle of muscle cells/fibres are surrounded by the endomysium.

Question 19

in the sympathetic NS, pre ganglionic neurones are…

Answer 19

cholinergenic (acetylcholine release)

Question 20

In the sympathetic NS, post ganglionic neurones are…

however when is this an exception?

Answer 20

noradrenergic (noradrenaline release)
-express nicotinic receptors (accept acetylcholine)
exception?
-perspiration (sweating) and ejaculation pathway-both cholinergenic

Question 21

In the parasympathetic NS, both pre and post ganglionic neurones are…

Answer 21

cholinergenic

-post ganglionic contain nicotinic receptors (accept ACh)