Cells of the nervous system

Question 1

What are the 4 functional regions of the brain?

Answer 1

Frontal
Parietal
Temporal
Occipital

Question 2

What does the brainstem consist of?

Answer 2

Midbrain
Pons
Medulla

Question 3

What are neurons?

Answer 3

Main functional cells of the nervous system

Question 4

What is the most basic type of neural cell?

Answer 4

Unipolar neural cell

Only one axonal projection

Question 5

What is the second type of neural cell?

Answer 5

Pseudo-unipolar

Single axonial projection that divides into two

Question 6

What is the third type of neural cells?

Answer 6

Bipolar

One axon but two projections from body

Question 7

What is the fourth type of neural cells?

Answer 7

Multipolar
Numerous projections from cells body
e.g. pyramidal cells, purkinje cells

Question 8

What are the 4 different types of neural cells?

Answer 8

Unipolar
Pseudo-unipolar
Bipolar
Multipolar

Question 9

What’s the deal with neurons?

Answer 9

Excitable cells of CNS
Heterogenous morphology
Non-dividing cells
Share common features

Question 10

What’s the deal with neurons?

Answer 10

Excitable cells of CNS
Responsible for electrical transmission
Heterogenous morphology
Non-dividing cells 
Share common features

Question 11

What is the function of the cell body?

Answer 11

Contains nucleus and ribosomes

Neurofilaments for structure and transport

Question 12

What’s the deal with the axon?

Answer 12

Long nerve fibre that originates from soma at axon hillock
Can branch off into collaterals
Usually covered in myelin

Question 13

What is an astrocyte?

Answer 13

Most abundant cells in CNS

Avle to proliferate

Question 14

What are the functions of astrocytes?

Answer 14

Structural cell: holds neurones in place and created the blood-brain barrier

Cell repair: Synthesise neurotrophic factors

Homes

Question 15

What are the functions of astrocytes?

Answer 15

Structural cell: holds neurones in place and created the blood-brain barrier

Cell repair: Synthesise neurotrophic factors

Homeostasis: Neurotransmitter removal and reuptake

Question 16

What is an oligodendrocyte?

Answer 16

Cell that produces myelin
Numerous projections
One oligodendrocyte myelinated many axons

Question 17

What are Schwann cells?

Answer 17

Produce myelin fo peripheral nerves

One Schwann cells myelinated one axon segment

Question 18

What are microglial cells?

Answer 18

Specialised cells similar to macrophages

Perform immune functions

Question 19

What are ependyma cells?

Answer 19

Epithelial cells lining the ventricles

Question 20

What are the 4 types of neuroglia cells?

Answer 20

Astroccytes
Oligodendrocytes
Microglia
Ependyma

Question 21

What are the 4 main physiological ions?

Answer 21

Potassium
Sodium
Chloride
Calcium

Question 22

What is RMP?

Answer 22

Resting membrane potential

Question 23

How can ions move through the membrane?

Answer 23

Channels and proteins

Question 24

Which ions have a high extracellular concentrations?

Answer 24

Na+

Cl-

Question 25

Which ions have a high extracellular concentrations in CNS?

Answer 25

Na+ | Cl-

Question 26

Which ions have a high intracellular concentrations in CNS?

Answer 26

K+

Question 27

What is the RMP of neuronal cells?

Answer 27

/

Question 28

What is the RMP of neuronal cells?

Answer 28

-40mv to -90mv

Question 29

How is an action potential generated?

Answer 29

Voltage-gated Na+ and K+ are closed Membrane depolarised: VGCS open, Na+ influx causes further depolarisation VGKS open at a slower rate and causes efflux of K+ causes membrane repolarisation

Question 30

What is saltatory conduction?

Answer 30

AP jumps between nodes of ranvier

Question 31

What are nodes of ranvier?

Answer 31

Small gaps of myelin intermittently along axon

Question 32

What are the main events at a synapse?

Answer 32

``` Propagation of action potential AP opens voltage gated calcium channels Neurotransmitter release from vesicles Neurotransmitter acts on post-synaptic membrane Activation of postsynaptic receptors? ```

Question 33

What are the three types of synapses?

Answer 33

Axodendritic Axosomatic Axoaxonic

Question 34

What are axodendritic synapses?

Answer 34

Connection between presynaptic terminal and neuronal dendrite

Question 35

What are axosomatic synapses?

Answer 35

Connection between presynaptic terminal and neuronal soma

Question 36

What are axoaxonic synpases?

Answer 36

Connection between presynaptic terminal and neuronal axon

Question 37

Define neuromuscular junction

Answer 37

Specialised structure incorporating axon terminal and muscle membrane allowing unidirectional chemical communication between peripheral nerve and muscle

Question 38

What happens at the neuromuscular junction?

Answer 38

``` Action potential propagated along axon Ca2+ entry ACh release into synapse ACh binds ti receptors of sarcolemma Change in end-plate potential ```

Question 39

What's the deal with the sarcolemma?

Answer 39

Skeletal muscle membrane T-tubules continuous with sarcolemma and closely connected to sarcoplasmic reticulum AP travel through T-tubules

Question 40

What's the deal with the sarcoplasmic reticulum?

Answer 40

Location: Surrounds myofibrils Function: Ca2+ storage and release following sarcolemma depolarisation Effect: Ca2+ causes myofibril and muscle contraction

Question 41

Name three disorder of the neuromuscular junction

Answer 41

Botulism Myasthenia Gravis Lamber-Eaton myasthenia syndrome

Question 42

How is Botulism caused?

Answer 42

Botulinum toxin irreversibly disrupts stimulation induced ACh release from presynaptic nerve terminal

Question 43

How is MG caused?

Answer 43

Autoimmune disorder Antibodies block ACh receptor Causes fatigable weakness

Question 44

How is Lamber-Eaton myasthenia syndrome caused?

Answer 44

Autoimmune disorder Antibodies directed against VGCC Prevents calcium entry