Organisation of Nervous System

Question 1

what are the two branches of the nervous system?

Answer 1

CNS and peripheral nervous system

Question 2

what are the two branches of the peripheral nervous system?

Answer 2

motor and sensory neurons

Question 3

what are the two branches of the sensory neurones?

Answer 3

somatic and autonomic

Question 4

what is the somatic nervous system?

Answer 4

controls voluntary movement

Question 5

what is autonomic nervous system?

Answer 5

controls involuntary movement

Question 6

what are the two branches of autonomic nervous system?

Answer 6

sympathetic and parasympathetic nervous system

Question 7

what is the sympathetic nervous system?

Answer 7

fight or flight

Question 8

what is the parasympathetic nervous system?

Answer 8

rest and digest

Question 9

what is the difference between sensory and motor neurones?

Answer 9

sensory is afferent and motor is efferent

Question 10

what are pre-ganglionic neurones?

Answer 10

ones that originate in the spinal cord or brainstem

Question 11

what are post-ganglionic neurones?

Answer 11

ones that lie in the peripheral nervous system in nerve cell called autonomic ganglia

Question 12

what is a chromaffin cell?

Answer 12

a type of cell that makes neurohormones which are chemicals that are made by nerve cells that signal other cells

Question 13

what role do pre-ganglionic neurones have?

Answer 13

creates synapses with chromaffin cells and stimulates the release of epinephrine

Question 14

what kind of muscles are involved in the somatic nervous system?

Answer 14

skeletal

Question 15

what kinds of muscles are involved in autonomic nervous system?

Answer 15

cardiac muscle, smooth muscle and glands

Question 16

where are nicotinic receptors found?

Answer 16

somatic neuromuscular junctions, autonomic ganglia and adrenal medulla

Question 17

where are muscarinic receptors found?

Answer 17

parasympathetic neuro-effector junctions

Question 18

what effect does epinephrine and norepinephrine have on the heart?

Answer 18

increases force and rate of contraction

Question 19

how does epinephrine effect blood vessels?

Answer 19

dilates vessels in skeletal muscle which decreases resistance and blood flow

Question 20

how does norepinephrine effect blood vessels?

Answer 20

increases blood flow via constriction of vessels in skin

Question 21

how does epinephrine effect blood pressure?

Answer 21

increases somewhat due to increased cardiac output

Question 22

how does norepinephrine effect blood pressure?

Answer 22

increases greatly due to vasoconstriction

Question 23

how does epinephrine effect airways?

Answer 23

dilates them

Question 24

how does norepinephrine effect airways?

Answer 24

dilates slightly

Question 25

how does epinephrine effect reticular formation?

Answer 25

activates

Question 26

how does norepinephrine effect reticular formation?

Answer 26

little effect

Question 27

what receptors does noradrenaline work on?

Answer 27

alpha or beta

Question 28

where does acetylcholine act upon muscarinic receptors?

Answer 28

in sympathetic nervous system in sweat glands

Question 29

how is adrenaline released into the blood stream?

Answer 29

released from adrenal medulla and acts upon nicotinic receptors which then causes it to be released into the blood stream

Question 30

where is there a ganglionic modification present?

Answer 30

in adrenaline release as no post-ganglionic neurone present, just one long ganglion

Question 31

what are the neurones like in the somatic nervous system?

Answer 31

single neurone with no ganglion

Question 32

what are the neurones like in parasympathetic nervous system?

Answer 32

long-pre ganglionic and short post-ganglionic

Question 33

what are the neurones like in sympathetic nervous system?

Answer 33

short pre-ganglionic and long post-ganglionic

Question 34

what receptors used in somatic nervous system?

Answer 34

nicotinic receptors

Question 35

what are nicotinic receptors used for?

Answer 35

rapid responses

Question 36

what is the structure of a nicotinic receptor?

Answer 36

5 subunits, with each producing different receptor subunits that have different pharmacological effects

Question 37

what is the skeletal and ganglionic subtype of the receptor?

Answer 37

skeletal is Nm and ganglionic is Nn

Question 38

what does binding of Ach do on nicotinic receptors?

Answer 38

binding causes the opening of sodium channels leading to depolarisation

Question 39

how is paralysis of skeltal muscles caused?

Answer 39

blocking of Nm receptors at somatic neurone-muscular junctions

Question 40

do the drugs causing skeletal muscle paralysis have an effect the autonomic nervous system?

Answer 40

no as the drugs only effect the Nm receptors and not Nn receptors and therefore only acts upon somatic nervous system

Question 41

what are the classes of neuromuscular blockers?

Answer 41

depolarising and non-depolarising

Question 42

what are non-depolarising blockers?

Answer 42

competitive agonists that compete with Ach for the receptor

Question 43

what are examples of non-depolarising drugs?

Answer 43

tubocurarine, pancuronium, vercuronium and rocuronium

Question 44

what kinds of drugs bind to somatic neuromuscular junctions?

Answer 44

competitive agonists

Question 45

what is tubocurarine and how does it work?

Answer 45

it is a competitive agonist that binds reversibly to receptor and prevents contraction

Question 46

how can effects of tubocurarine be reversed?

Answer 46

concentrations of Ach can be increased

Question 47

what did Claude Bernard do?

Answer 47

concluded that the site of paralysis is between the nerve and the junction as when the nerve was stimulated there was no contraction but contracted when muscle stimulated

Question 48

what are the clinical uses of tubocurarine?

Answer 48

used for tube intubation, muscle relaxation during surgery, effects last about 30 minutes and does not cause muscle spasms

Question 49

what is the negative effects of tubocurarine?

Answer 49

causes histamine release which causes vasodilation which therefore causes reception in blood pressure, itching and bronchoconstriction

Question 50

what are the characteristics of rucaronium?

Answer 50

rapid onset and acts as a muscle relaxant, does not act as a depolarising block so rarely needs reversal

Question 51

what are depolarising blockers?

Answer 51

persistant agonists that cause constant stimulation of nicotinic receptors

Question 52

what is an example of a depolarising blocker?

Answer 52

suxamethonium/succinylcholine

Question 53

how does succinylcholine work?

Answer 53

chemically similar to Ach so stimulates nicotinic Nm receptors yet cannot be broken down so remains in the cleft until the receptor looses sensitivity

Question 54

what are the effects of succinylcholine? how is it terminated?

Answer 54

causes muscle spasms for a few seconds and then paralysis, terminated using pseudocholinesterase in the plasma

Question 55

how quickly does succinylcholine work?

Answer 55

within 30 seconds

Question 56

what drugs enhance cholinergic transmission?

Answer 56

physostigmine by blocking breakdown via AchE

Question 57

what is physostigmine used for?

Answer 57

treating glaucoma

Question 58

what is myasthenia gravis?

Answer 58

causes a reduces effect of receptors causing muscle weakness and fatigue

Question 59

how is myasthenia gravis treated?

Answer 59

using reversible anticholinesterases which inhibit AchE causing more Ach to be present causing greater stimulation

Question 60

what is botulinum toxin?

Answer 60

it inhibits Ach release and is injected into the muscles to reduce spasm

Question 61

what are the negative effects of botulinum toxin?

Answer 61

causes progressive parasympathetic and somatic paralysis leading to respiratory failure