pharmacology

Question 1

what is the axon hillock

Answer 1

site of initiation of the all or non action potential

Question 2

what does the axon do

Answer 2

conducts output signals as action potentials to other neurones
mediates transport of materials between the soma and presynaptic terminal

Question 3

describe a pseudounipolar neurone

Answer 3

one neurite that bifurcates ‘splits’

Question 4

where do you find unipolar neurones

Answer 4

peripheral autonomic neurone

Question 5

where do you find pseudo unipolar neurones

Answer 5

dorsal root ganglion

Question 6

where do you find bipolar neurones

Answer 6

retinal ganglion

Question 7

where do you find multipolar neurones

Answer 7

lower motor neurone

Question 8

what are the four functional regions of neurone

Answer 8

input
integrative
conductile
output

Question 9

where would you find a projection neurone

Answer 9

from dorsal horn of spinal cord to brain structures

Question 10

what channel mediates the upstroke

Answer 10

voltage activate na channels

Question 11

what channel mediates the downstroke

Answer 11

voltage activated k channels

Question 12

what does the distance over which current spread depend on

Answer 12

membrane resistance and axial resistance of the axoplasm

Question 13

what is a factor in the propagation of the action potential

Answer 13

passive conduction

Question 14

the x the length constant the greater the local current spread

Answer 14

the longer the length constant the greater the local current spread

Question 15

what does greater local current spread increase

Answer 15

AP conduction velocity

Question 16

what is the most common form of synapse

Answer 16

axodendritic

and the axosomatic

Question 17

what activates postsynaptic cation selective

Answer 17

glutamate

Question 18

in the CNS what is the most frequent excitatory synapse transmitter

Answer 18

glutamate

Question 19

what does GABA or glycine activate

Answer 19

post synaptic ANION selective ionotropic GABA or glycine receptors

Question 20

what is contained in the vesicles

Answer 20

neurotransmitter

Question 21

presynaptically where do the vesicles cluster

Answer 21

around the active zones

Question 22

postsynaptically where do the vesicles cluster

Answer 22

postsynaptic density

Question 23

where are amino acids and amines released from

Answer 23

synaptic vesicles

Question 24

where are peptides released from

Answer 24

secretory vesicles

Question 25

what can glutamate, GABA, glycine, acetylcholine and 5HT activate that mediates fast neurotransmission

Answer 25

ionotropic ligand gated ion channels (LGICs)

Question 26

do GPCR allow fast or slow neurotransmission

Answer 26

slow

Question 27

what can activate GPCR

Answer 27

glutamate, GABA, acetylcholine and 5HT (NOT glycine)

Question 28

where do glycine and glutamate occur

Answer 28

in all cells-not just in neurones

Question 29

where do GABA and amines occur

Answer 29

they must be specifically synthesised by the neurones that release them

Question 30

where are the enzymes that make GABA and amines found

Answer 30

they are synthesised in the cell body and are transported to the presynaptic terminal by AXOPLASMIC transport along microtubules

Question 31

which types of cells are macroglia

Answer 31

astrocytes, oligodendrocytes, Schwann cells, Capsular cells

Question 32

what are ependymal cells

Answer 32

ciliated cells that line the ventricles of the brain and central canal of the spinal cord-they help form and circulate the CSF

Question 33

what are the most numerous cells in the nervous system

Answer 33

astrocytes

Question 34

which part of astrocytes help form the blood brain barrier

Answer 34

perivascular end-feet which surround capillaries

Question 35

what are the function of astrocytes

Answer 35

control of electrolyte balance in the CNS-particularly extracellular K+ PRODUCTION OF NEUROTROPHINS NECESSARY FOR NEURONAL SURVIVAL uptake of neurotransmitters eg glutamate, GABA supplying glutamine for synthesis of neurotransmitter glutamate regulating the tightness of the BBB

Question 36

what are astrocytes highly susceptible to

Answer 36

the formation of neoplasms

Question 37

what does a Na channel agonist do

Answer 37

closes the channels favours inhibition

Question 38

example of a na channel agonist

Answer 38

lidocaine

Question 39

how are neurotransmitters inactivated

Answer 39

neurotransmitter can be returned to axon terminals for reuse or transported into glial cells enzymes inactivate neurotransmitters neurotransmitters can diffuse out of the synaptic cleft

Question 40

how can neurotransmitters act on ion channels

Answer 40

directly or indirectly

Question 41

direct gating is by

Answer 41

IONOTROPIC RECEPTROS

Question 42

Indirect gating is by

Answer 42

METABOTROPIC RECEPTORS

Question 43

what is the major excitatory neurotransmitter

Answer 43

glutamate

Question 44

what do non NMDA ionotropic receptors mediate

Answer 44

fast excitatory synaptic transmission

Question 45

what are examples of non NMDA ionotropic receptors

Answer 45

AMPA and kainite

Question 46

give examples of selective blockers of NMDA channels

Answer 46

ketamine and phencyclidine

Question 47

what are NMDA channels highly permeable to

Answer 47

Ca2+ and hence they are thought to promote neurotoxicity

Question 48

what are ionotropic and metabotropic glutamate receptors important in discriminating in

Answer 48

ON and OFF retinal pathways

Question 49

what is the main inhibitory neurotransmitter in the CS

Answer 49

GABA

Question 50

GABA acts on what two receptors

Answer 50

Ionotropic GABAa receptor that operates a CL- channel | GABAb metabotropic which often activates a K channel