Physiology

Question 1

Name five physical parts of a neuron.

Answer 1

Neurite- Dendrite
Soma
Axon hillock
Neurite- Axon
Synapse

Question 2

What does the dendrite do?

Answer 2

Receive input

Question 3

What is the soma?

Answer 3

Cell body

Question 4

What happens at the axon hillock?

Answer 4

All or nothing

Question 5

What are the four shapes a neuron can be?

Answer 5

Unipolar
Pseudounipolar
Bipolar
Multipolar

Question 6

Describe a unipolar neuron

Answer 6

Soma -> Neurite (axon)

Peripheral autonomic N

Question 7

Describe a pseudounipolar neruron

Answer 7

One bifurcated neuron with central and peripheral neurites.

DRG N

Question 8

Describe a bipolar neuron

Answer 8

Neurite -> Soma -> Neurite

Retinal cells

Question 9

Describe a multipolar neuron

Answer 9

Many dendrites on soma -> axon

LMN

Question 10

What is a neurite?

Answer 10

Process from soma (axon or dendrite)

Question 11

What are the four functional regions of a neuron

Answer 11

Input (Dendrite normally)
Integration (Axon Hillock)
Conduction (Axon)
Output (Synapse)

Question 12

Name two types of input

Answer 12

Sensory

Synaptic

Question 13

What is the RMP?

Answer 13

~-70mV

Question 14

What causes the upstroke of the AP?

Answer 14

Na influx

Question 15

Where does the AP peak?

Answer 15

~30-40mV

Question 16

What causes the downstroke of the AP?

Answer 16

K efflux

Question 17

What happens on repolarisation?

Answer 17

Overshoot

Question 18

How far does the AP tend to overshoot?

Answer 18

~-80mV

Question 19

Why is it beneficial for the axon to be leaky?

Answer 19

To prevent propagation of passive signals

Question 20

What two factors increase signal conductance?

Answer 20

Larger neuron and myelination

Question 21

What two cells myelinate neurons?

Answer 21

Schwann cells- PNS

Oligodendrocytes- CNS

Question 22

What is demyelination in the PNS called?

Answer 22

Guillian-Barré syndrome

Question 23

What is demyelination in the CNS called?

Answer 23

MS

Question 24

What causes vesicle binding?

Answer 24

Ca

Question 25

How wide is the synaptic cleft?

Answer 25

20-50nm

Question 26

What are the three locations of synapse?

Answer 26

Axodendritic- Very common
Axosomatic- Common
Axoaxonic- Uncommon

Question 27

What are the two broad types of synapse?

Answer 27

Chemical

Electrical

Question 28

What two types of signal are neurons capable of transmitting?

Answer 28

Excitatory

Inhibitory

Question 29

What is the most common excitatory NT in the PNS and CNS respectively?

Answer 29

PNS- ACh

CNS- Glutamate

Question 30

What are the two most common inhibitory NT in the CNS?

Answer 30

GABA and glycine

Question 31

What three chemical categories of NT are there?

Answer 31

AA
Amines
Peptide

Question 32

Give some examples of AA NT

Answer 32

Glutamate
GABA
Glycine

Question 33

Give some examples of amine NT

Answer 33

Dopamine
Histamine
NA
Serotonin (5HT)

Question 34

Give some examples of peptide NT

Answer 34

CCK
Enkephalin
Neuropeptide Y
Somatostatin
Substance P
TRH
VIP

Question 35

Where are ACh, AA and amine NT released from?

Answer 35

Synaptic vesicle

Question 36

Where are peptide NT released from?

Answer 36

Secretory vesicles

Question 37

What two types of NT receptor are there?

Answer 37

Ionotropic (Ligand gated ion channel)

Metabotropic (GCPR)

Question 38

Which one NT does not have GCPRs?

Answer 38

Glycine

Question 39

What are the three types of glutamate ionotropic R?

Answer 39

AMPA- Fast
Kainate- Fast
NMDA- Slow

Question 40

What ions are AMPA and Ka R selective for?

Answer 40

Na and K

Question 41

What ions is NMDA R selective for?

Answer 41

Na, Ca and K

Question 42

Are glutamate metabotropic R excitatory or inhibitory?

Answer 42

Inhibitory

Question 43

Why are NMDA R cytotoxic?

Answer 43

Ca influx

Question 44

What drugs can act on MNDA R?

Answer 44

Ketamine etc

Question 45

What do metabotropic NMDA R do?

Answer 45

Presynaptic to modulate NT release (block Ca)