L13

Question 1

describe a multipolar neuron

Answer 1

multiple dendrites project from cell body

Question 2

describe a bipolar neuron

Answer 2

single dendrite opposite from axon

Question 3

describe a pseudo-unipolar neurone

Answer 3

axon and dendrite rise from a common stem of the cell body

Question 4

what does it mean if a neuron has a large nucleus

Answer 4

large metabolic demand

Question 5

what does many mitochondria in a neuron mean?

Answer 5

high metabolic demand

Question 6

where can ER be found and in what kind of neurons?

Answer 6

found in dendrites of large neurons

Question 7

what makes up the cytoskeleton of a neuron?

Answer 7

neurofilaments and microtubules

Question 8

where are synapses found? 2

Answer 8

dendrites and cell body

Question 9

what is the CNS split into?

Answer 9

white matter and grey matter

Question 10

what is grey matter?

Answer 10

neuron cell bodies, dendrites and axons

Question 11

what is white matter?

Answer 11

axons, many myelinated

Question 12

what do glial cells do?

Answer 12

support the CNS

Question 13

what is an oligodendrocyte equivalent to?

Answer 13

Schwann cell

Question 14

what does an oligodendrocyte do in the CNS?

Answer 14

myelinates axons

Question 15

what do astrocytes do?

Answer 15

provide mechanical support

Question 16

What are astrocytes also a part of?

Answer 16

blood brain barrier

Question 17

what are microglia?

Answer 17

specialised immunological cells of the CNS

Question 18

what are ependymal cells?

Answer 18

ciliated cuboidal epithelial cells

Question 19

where do you find ependymal cells?

Answer 19

lining the cavities of the brain and spinal cord

Question 20

what 4 things do peripheral nerves consist of?

Answer 20

fascicle, endoneurium, perineurium and epineurium

Question 21

what is a fascicle?

Answer 21

a bundle of nerve fibres

Question 22

what is endoneurium?

Answer 22

a collagenous support tissue that surrounds axons inside the fascicles

Question 23

what is perineurium?

Answer 23

a dense collagenous tissue surrounding indvidual fascicles

Question 24

what is epineurium?

Answer 24

loose collagenous tissue surrounding bunch of fascicles/the nerve

Question 25

what are PNS axons enveloped by?

Answer 25

Schwann cells

Question 26

what do Schwann cells provide PNS axons?

Answer 26

structural and metabolic support

Question 27

are axons with small diameter fibres myelinated?

Answer 27

no

Question 28

are axons with large diameter fibres myelinated?

Answer 28

yes

Question 29

when an axon is becoming myelinated, what is it first invaginated into?

Answer 29

the Schwann cell cytoplasm

Question 30

what does the outer membrane of the Schwann cell fuse to form?

Answer 30

a mesaxon

Question 31

what does the mesaxon do?

Answer 31

rotates around the axon, wrapping it in concentric layers of membrane

Question 32

what does the wrapping of the membrane around the mesaxon form?

Answer 32

the myelin sheath

Question 33

what are the gaps in between Schwann cells on an axon called?

Answer 33

Nodes of Ranvier

Question 34

are these gaps also found in CNS in oligodendrocyte myelination?

Answer 34

yes

Question 35

what exists across the plasma membrane of all cells?

Answer 35

an electrical potential

Question 36

what kind of excess charge does the fluid inside the cell have?

Answer 36

negative

Question 37

what kind of excess charge does the fluid outside the cell have?

Answer 37

positive

Question 38

are myelinated or non-myelinated nerves slower to conduct AP's?

Answer 38

non-myelinated

Question 39

how do the Nodes of Ranvier increase conduction velocity?

Answer 39

the AP can jump quickly between the nodes

Question 40

what are multiple sclerosis, Guillain-Barre syndrome and myasthenia gravis?

Answer 40

autoimmune diseases

Question 41

what does the immune system attack if you have MS?

Answer 41

the myelin of CNS

Question 42

what is the result of the attack on myelin of CNS if you have MS?

Answer 42

slows down or blocks messages between brain and body

Question 43

what are 5 symptoms of MS?

Answer 43

visual disturbances, muscle weakness, trouble with coordination and balance, numbness (and pins and needles), thinking and memory problems

Question 44

what does the immune system attack if you have GB syndrome?

Answer 44

myelin of PNS

Question 45

what are 2 direct symptoms of GB syndrome?

Answer 45

tingling in hands and feet, progressing weakness of limbs and respiratory muscles

Question 46

effects on autonomic nervous system can lead to what 2 symptoms if you have GB syndrome?

Answer 46

altered heart rate and blood pressure

Question 47

what is a synapse?

Answer 47

a specialised intercellular junction which links neurones to each other and to muscles

Question 48

where does the propagating axon terminate?

Answer 48

the terminal bouton

Question 49

what does the AP from the propagating axon elicit release of?

Answer 49

neurotransmitter

Question 50

where is neurotransmitter released from?

Answer 50

synaptic vesicles

Question 51

where is neurotransmitter released into?

Answer 51

synaptic cleft

Question 52

neurotransmitter diffuses across the synaptic cleft and stimulates what?

Answer 52

the receptor on the postsynaptic membrane

Question 53

when neurotransmitter stimulates the postsynaptic cell, how does it respond?

Answer 53

usually an AP in the effector cell

Question 54

what are the 5 neurotransmitters?

Answer 54

noradrenaline, glutamate, dopamine, acetyl-choline, serotonin

Question 55

what are neurotransmitters synthesised by?

Answer 55

biochemical pathways

Question 56

the loss of what enzyme leads to deficiency in several neurotransmitters?

Answer 56

GTP cyclohydrase 1

Question 57

what 5 symptoms does GTPCH deficiency cause?

Answer 57

intellectual disability, convulsions, irritability, hypersalivation, difficulty breathing

Question 58

how long does GTPCH deficiency take to onset?

Answer 58

4-5 months

Question 59

what can you treat GTPCH deficiency with?

Answer 59

neurotransmitter precursors

Question 60

what is a neuromuscular junction?

Answer 60

the synapse between motor neurons and muscle fibre

Question 61

what is the neuromuscular junction also known as?

Answer 61

motor end plate

Question 62

how many muscle fibres can one motor neuron innervate?

Answer 62

thousands

Question 63

what is a motor unit?

Answer 63

a motor neuron and connected skeletal muscle fibres

Question 64

in terms of athletic performance, what does more muscle fibres mean?

Answer 64

better at power movements

Question 65

in terms of athletic performance, what does less muscle fibres mean?

Answer 65

better at endurance

Question 66

what is the first step of neuromuscular activity?

Answer 66

acetylcholine is released from synaptic vesicles

Question 67

in the second step of neuromuscular activity, what does the acetylcholine bind to and to cause what?

Answer 67

binds to nicotinic ion channels that cause sarcolemma membrane depolarisation

Question 68

what are secondary synaptic clefts?

Answer 68

when the synaptic cleft folds to accept the neurotransmitter, between the folds are secondary synaptic clefts

Question 69

what occurs in the third part of neuromuscular activity?

Answer 69

NMJ occupies a recess on the muscle surface

Question 70

what is a sole plate?

Answer 70

a recess on the muscle surface

Question 71

what are the stops of an AP's activity?

Answer 71

acetylcholine is released in response to AP in motor neuron, binds to nicotinic receptors, then travels along the sarcolemma, into the t-tubule and into the sarcoplasmic reticulum

Question 72

what does your body produce if you have myasthenia gravis?

Answer 72

antibodies to nicotinic receptors

Question 73

what is blocked if you have myasthenia gravis and what does this inhibit?

Answer 73

binding of acetylcholine meaning muscle activation is inhibited

Question 74

what are the most commonly affected muscles of myasthenia gravis?

Answer 74

eyes and face (those associated with swallowing)

Question 75

what can alleviate symptoms of myasthenia gravis?

Answer 75

acetylcholinesterase inhibitors and immune suppressors

Question 76

what is botox called?

Answer 76

botulinum toxin A

Question 77

what does botox regulate?

Answer 77

ACh release from nerve terminals

Question 78

what does botox selectively inhibit?

Answer 78

underlying muscles ability to contract