neurochem

Question 1

neuron structure

Answer 1

dendrites go out, cell body, nucleus, axon, myelin sheath, terminal fibers, synapse and synaptic cleft

• nucleus has mito

Question 2

synapse

Answer 2

1 nerve ending and dendrite meet

• presynaptic and post synaptic with vescicles and receptors

Question 3

resting membrane potential

Answer 3

70 mv with high - inside. k is inside, cl and na outside

Question 4

action potential

Answer 4

• membrane is lowered to -50
• allows na in and k out
• potential is +30 now, gives impulse
• happens in 1 sec
• na k atapse pumps na out and k in

Question 5

na k permeability

Answer 5

voltage gated channels, only open when nerve impulse hits axon and terminal fiber to allow/nnot allow nerve impulse

Question 6

calciym

Answer 6

release of NT from cleft is ca dependent

- AP causes ca to enter cleft

Question 7

blood brain barrier

Answer 7

• endothelial cell lined wiyh tight junctions

Question 8

acetylcholine

Answer 8

• see structure
• associated with skeletal muscle, motor neurons and attention and self awareness in CNS
• EXCITATOTIR

Question 9

acetylcholine made + how it works

Answer 9

made in presyn
- see reaction

• binds to receptor on post syn, na channel is opened to let na in
• neuron is depolarized (closer to threshold so more +)
• after it has boumd it gets attacked by acetylcholineesterase

Question 10

acetylcholineesterase

Answer 10

• see reaction

- acetate and choline taken back up into presyn

Question 11

nicotinic

Answer 11

• nicotine is mimicing action of acetylcholine (agonist)
• found in skeletal muscle
• cobra toxin binds to this type + blocks receptor

Question 12

muscarinic

Answer 12

• binds atropine

- smooth muscle and brain

Question 13

myasthenia gravis

Answer 13

• some disease to do with antibodies against nicotinic receptor
• muscle weakness

Question 14

catecholamines

Answer 14

• dopa and norepi
• excit/inhibit depending on
• often inhibtory using cl- ions and increase camp by increasing adenyl cyclase

Question 15

dopamine

Answer 15

• dopamine controls movement
• parkinsons is death of dopamine neurons so less dopamine is made
• shiophroena is excess dopamine transmission so also less dopamine

Question 16

serotonin

Answer 16

• mediate sleep and sensory perception

- LSD binds to this to decfease it?

Question 17

gaba

Answer 17

inhibitory

• increases cl transport into post synapse
• hyperpolarizes
• valium binds here
• some reaction written

Question 18

glial cells

Answer 18

non neuronal.

• microglia clean debris
• macroglia make myelin (white matter) and guide axons in brain dev
• astrocytes are star shaped that buffer ions and metabolites

Question 19

glutamate

Answer 19

• excitatory

- involved in plasticity and neurotoxicity

Question 20

plasticity

Answer 20

involves long term potentiation or depression

• potentiation means long lasting enhancement in synpase efficacy
• depression is reduction

Question 21

nerve impulse and glu

Answer 21

glu is released as impulse reaches pre synaptic end and ninds to receptor causing na release
- made inside astrocyte where g.u is converted to gln

Question 22

glycine

Answer 22

• inhinitory of spinal chord and brain stm

Question 23

cocaine

Answer 23

• plant alkaloid from coca shrub

- blocks re-uptake of norepi from synpatic cleft

Question 24

brain opiates

Answer 24

• analgesic (releive pain)
• produce euphora (well being feeling)
• addictive with emotional/physical dependence
• tolerance (take more to get effect)
• withdrawl

Question 25

opium from poppy

Answer 25

10 is morpheine - see structure - if you acetylate, you get heroin

Question 26

antagonist

Answer 26

drug that produce none of the effects of the parent drug and blockj the effects

Question 27

mixt agonist

Answer 27

antagonist. drug that makes some effects of parent drug but blocks others

Question 28

enkephalin, met and leu

Answer 28

met enkephaline is a penta peptide (tyr, gly, gly, phe, met) leu enkephain is tyr, gly,gly, phe, leu - bind to train receptors

Question 29

b endorphin

Answer 29

protein with pentapeptide sequence

Question 30

acth

Answer 30

made in pituitary gland | - naturally make b endorphins

Question 31

enkephalin effect

Answer 31

- decrease na flo - inhibit neurons that normally are excitatory - involved in modulation of neurons that reulate pain, keep pain threshold high so no pain

Question 32

drug mechanism: tolerance

Answer 32

- increase degradative enzymes so more drug to make more effect

Question 33

drug mech: enkephalin

Answer 33

- without drugs, we have a level of enkephalin - with drugs, drug binds in place of enkephalins so down reg of it and fewer enkephalins - tolerance - withdrawl

Question 34

drug mech: adennylate cyclase

Answer 34

- cell needs camp, - enkephalins inhibit so less camp - body increases receptors to restore levels of camp - more drug = more inhibit