1a Cells of the Nervous System

Question 1

What are the four lobes of the brain called?

Answer 1

Frontal, temporal, parietal and occipital

Question 2

What does the frontal lobe do?

Answer 2

Executive functions like personality

Question 3

What does the parietal lobe do?

Answer 3

Contains the somatosensory cortex for processing tactile information

Question 4

What does the temporal lobe do?

Answer 4

Contains the hippocampus (short term memory), amygdala (behaviour) and Wernicke’s area (auditory and speech)

Question 5

What does the occipital lobe do?

Answer 5

Processing of visual information

Question 6

What is the function of the cerebellum?

Answer 6

Fine movement, balance and fine coordination

Question 7

What is a soma?

Answer 7

A cell body (aka perikaryon)

Question 8

What is a unipolar neurone?

Answer 8

Single cell body with 1 axonal projection

Question 9

What is a bipolar neurone?

Answer 9

Single cell body with 2 projections (axon + dendrite)

Question 10

What is a pseudo-unipolar neurone?

Answer 10

Single axonal projection splits into two
Cell body is not embedded into the axon

Question 11

What are the three shapes of the multipolar cells?

Answer 11

Pyramidal, Purkinje and Golgi cells

Question 12

What multipolar cell type is this?

Answer 12

Pyramidal

Question 13

What multipolar cell type is this?

Answer 13

Purkinje

Question 14

What multipolar cell type is this?

Answer 14

Golgi

Question 15

What are dendrites?

Answer 15

Projections off the axon which receive signals from other neurones and are not covered in myelin

Question 16

What is an astrocyte? And what is its function?

Answer 16

A highly abundant cell which is important in maintaining blood brain barrier and keeping the neurones in place

They function as structural cells and are known to play an important role in cell repair, synapse formation, neuronal maturation and plasticity.

Question 17

What is the function of the oligodendrocytes?

Answer 17

They produce myelin in the CNS

Question 18

How many cells do oligodendrocytes produce myelin for?

Answer 18

Myelinates many axons

Question 19

What is the function of a Schwann Cell?

Answer 19

Functions to produce myelin for the peripheral nervous system

Question 20

How many axons does one schwaan cell myelinate?

Answer 20

One

Question 21

What are microglial cells?

Answer 21

They are the immune cells of the CNS
(similar to macrophages)

Question 22

What are ependymal cells?

Answer 22

Epithelial cells lining the ventricles that regulate the production of cerebospinal fluid

Question 23

How is resting membrane potential generated?

Answer 23

3Na+ pumped out for every 2K+ that are pumped in
Results in a high concentration of Na+ outside the neurone
Sets up a high concentration gradient so that Na+ can flow in to generate an action potential

Question 24

Is the inside of the neurone more positive or negative than the outside?

Answer 24

More negative

Question 25

What helps to move the NA+ and K+ ions to generate resting membrane potential?

Answer 25

The Na+/K+ ion pump (active transport so ATP dependent)

Question 26

Which ions are in high concentration outside the neurone?

Answer 26

Na+ and Cl-

Question 27

Which ions are in high concentration inside the neurone?

Answer 27

K+

Question 28

What is the resting membrane potential?

Answer 28

-70mV

Question 29

When the inside of the neurone becomes more negative, what is this known as?

Answer 29

Hyperpolarisation

Question 30

When the inside of the neurone becomes more positive, what is this known as?

Answer 30

Depolarisation

Question 31

What is the neuromuscular junction?

Answer 31

The junction between the motor neurone and muscle

Question 32

Describe what happens at the neuromuscular junction?

Answer 32

1. Action potential arrives at the pre-synaptic bouton 2. Ca2+ ion channels open 3. Ca2+ binds to NT vesicles containing ACh 4. They diffuse and ACh released into synaptic cleft through exocytosis 5. ACh binds to nicotinic ACh receptors on sarcolemma of skeletal muscle 6. Action potential then travels down the T-tubules which runs close to the sarcoplasmic reticulum 7. The depolarisation of the sarcolemma causes the sarcoplasmic reticulum to release Ca2+ which leads to muscle contraction

Question 33

What is botulism?

Answer 33

When botulinum toxin disrupts the ACh release from the pre-synaptic terminal, leading to muscle weakness

Question 34

What is the name of the condition where you produce **autoantibodies against the nAChr's** on the skeletal muscle?

Answer 34

Myasthenia gravis

Question 35

What is Lambert-Eaton Myastenic Syndrome?

Answer 35

An autoimmune disorder where you produce **antibodies directed against voltage gated calcium channels**

Question 36

What is the difference between Myasthenia Gravis and Lambert-Eaton Myastenic Syndrome?

Answer 36

MG = antibodies against nAChrs Lambert-Eaton = antibodies against voltage gated calcium channels

Question 37

What are golgi cells?

Answer 37

GABA neurones found in the cerebellum

Question 38

What are purkinje cells?

Answer 38

GABA neurones found in the cerebellum

Question 39

What are pyramidal cells?

Answer 39

Cells with pyramid shaped cell bodies

Question 40

What are the three common features of neurones?

Answer 40

Soma, axon and dendrites

Question 41

What is the difference between dendrites and axons?

Answer 41

Dendrites are highly branched and are not covered in myelin

Question 42

What can axons branch off into?

Answer 42

Collaterals

Question 43

What are microglia?

Answer 43

Neuronal macrophages

Question 44

At resting membrane potential, what happens to the voltage-gated Na+ channels (VGSCs) and voltage-gated K+ channels (VGKCs) ?

Answer 44

They are closed

Question 45

What happens to the voltage gated sodium channels when the membrane undergoes depolarisation?

Answer 45

Sodium influx

Question 46

What causes membrane repolarisation?

Answer 46

VGKCs opens at a slower rate and cause efflux of K+ from cell

Question 47

What pump restores the ion gradients across the membrane of a neurone?

Answer 47

Na+/K+ ATPase pump

Question 48

How does the myelin prevent the AP from spreading?

Answer 48

It high resistance and low capacitance

Question 49

What are the nodes of ranvier?

Answer 49

Small gaps of myelin intermittently along axon

Question 50

What is saltatory conduction?

Answer 50

The jumping of the AP between the nodes of ranvier

Question 51

What is an axodendritic cell?

Answer 51

Connection between **presynaptic terminal** and a **neuronal dendrite**

Question 52

What is a axosomatic synapse?

Answer 52

Connection between **presynaptic terminal** and **neuronal soma**

Question 53

What is an axoaxonic synapse?

Answer 53

Connection between **presynaptic terminal** and **neuronal axon**

Question 54

What type of communication occurs between nerve and effector cells?

Answer 54

Paracrine communication due to neurotransmitter release

Question 55

What is the pathophysiolgy of Botulism?

Answer 55

Botulinum toxin (BTx) irreversibly disrupts stimulation-induced ACh release from presynaptic nerve terminal

Question 56

What symptoms does myasthenia gravis cause?

Answer 56

Fatigable, painless muscle weakness that improves with rest Severe facial weakness

Question 57

What symptoms does Lambert-Eaton myastenic syndrome cause?

Answer 57

Generalised fatigue and weakness

Question 58

What symptoms does botulism cause?

Answer 58

Difficulty swallowing Muscle weakness Double vision Drooping eyelids Blurry vision Slurred speech Difficulty breathing