Physiology: Neurones, nerve conduction and synaptic transmission

Question 1

What is retrograde transport, in the context of neurones?

Answer 1

The fact that material can be transported between the soma (cell body) and presynaptic terminal and vice versa.

Question 2

Name three disease processes that make use of retrograde transport to infect neurones?

Answer 2

Herpes
Polio
Rabies

Question 3

Give an example of a unipolar neurone

Answer 3

Peripheral autonomic neurone

Question 4

Give an example of a pseudounipolar neurone

Answer 4

Dorsal root ganglion

Question 5

Give an example of a bipolar neurone

Answer 5

Retinal bipolar neurone

Question 6

Give an example of a multipolar neurone

Answer 6

Lower motor neurone

Question 7

What is the length constant (λ)?

Answer 7

A constant used to quantify the distance that a graded electric potential will travel along a neurite via passive electrical conduction.

Question 8

Will the local current spread be longer or shorter with a larger length constant

Answer 8

larger

Question 9

What is the most common excitatory neurotransmitter in the CNS?

Answer 9

Glutamate

Question 10

What is the most common inhibitory neurotransmitter in the CNS?

Answer 10

GABA ( γ-aminobutyric acid) or glycine

Question 11

Is a excitatory response depolarizing or hyperpolarizing?

Answer 11

Depolarizing

Question 12

Is an inhibitory response depolarizing or hyperpolarizing?

Answer 12

Hyperpolarizing

Question 13

What kind of receptors does glutamate activate?

Answer 13

Cation selective, ionotropic glutamate receptors

Question 14

What kind of receptors does GABA or glycine activate?

Answer 14

Anion selective ionotropic recpetors

Question 15

What are the three main morphological types of synpase. List from most common to least common!

Answer 15

1. Axodendritic
2. Axosomatic
3. Axoaxonic

Question 16

What is a synapse?

Answer 16

A junction between two neurones (most commonly between the axon terminal of one neuron and the dendrites or cell body of the next)

Question 17

Describe briefly the events that occur at a synapse

Answer 17

1. Action potential triggers the opening of voltage gated calcium channels
2. This causes the release of neurotransmitter from some of the synaptic vesicles into the synaptic cleft.
3. This neurotransmitter diffuses across the synaptic cleft and binds with specific protein receptor sites and activates changes the ion permeability there.

Question 18

With regard to Na+ and K+ describe the differences between excitatory and inhibitory synapses.

Answer 18

Change in permeability at excitatory synapses results in the influx of sodium into the postsynaptic neurone whereas inhibitory synapses result in the influx of chlorine into the postsynaptic neurone.

Question 19

Name three amino acid neurotransmitter substances

Answer 19

Glutamate
GABA
Glycine

Question 20

Name 5 amine neurotransmitters

Answer 20

Acetylcholine
Dopamine
Noradrenaline
Seratonin
Histamine

Question 21

Name 8 peptide neurotransmitters

Answer 21

Cholecystokinin
Dynorphin
Enkaphalins
Neuropeptide
Y
Somatostatin
Substance P
Thyrotrophin releasing hormone
Vasoactive intestinal polypeptide