autonomic nervous system

Question 1

ganglion neurone

Answer 1

collection of neuronal bodies found in the voluntary and autonomic branches of the peripheral nervous system (PNS).

Question 2

Parasympathetic paths

Answer 2

Cranial nerve III controls eyes
Vagus nervous system controls glands
sacral s2-s4 controls the bladder and genitals

Question 3

What acetylcholine affects

Answer 3

Somatic- skeletal muscle
Sympathetic-glands, adrenal medulla
Parasympathetic- salivary glands

Question 4

Types of receptors for acetylcholine

Answer 4

Muscuerinic

Nicotonic

Question 5

Nicotinic acetylcholine receptor

Answer 5

Ligand gated channel that has 5 sub units
Has 2 binding spots for Ach
Stimulates adrenaline secretion from adrenal medulla

Question 6

Muscarinic Ach receptor

Answer 6

G protein coupled receptor
Causes release of calcium ions and inhibits
Causes activation of sweat glands

Question 7

M2 receptor(cardiac)

Answer 7

Decreased cAMP
Causes inhibitory affect
Potassium ion increase and calcium ion decrease
Ca2+ decreases heart rate

Question 8

M1 receptor(neural)

Answer 8

Activates phospholipase C increasing IP3 and DAD

Excites CNS and ganglia

Question 9

M3 receptor

Answer 9

Activates phospholipase C and increases IP3 and DAG

Causes smooth muscle contraction and vasodilation

Question 10

cholinergic transmission

Answer 10

Acetylcholine can be taken back to the presynaptic terminal by the transporter choline carrier
Choline can then be catalysed by choline acetyltransferase to form Ach again
This can then be transported back to the vesicle through Ach carrier choline

Question 11

Drugs on cholinergic transmission

Answer 11

Atropine inhibits the effect of acetylcholine by complexing the acetylcholine receptor
Cholinesterase inhibitors function to decrease the breakdown of acetylcholine

Question 12

depolarizing agents vs nondepolarizing

Answer 12

depolarizing muscle relaxants act as ACh receptor agonists, whereas nondepolarizing muscle relaxants function as competitive antagonists

Question 13

Muscuerinic agonists

Answer 13

Acts for parasympathetic system
Decreased heart rate
smooth muscle contraction
Sweating and salvation 
Affects CNS by causing excitation

Question 14

Nicotine

Answer 14

stimulates ganglia and neuromuscular junction and causes a depolarising block
Depolarising block is now desensitised to anymore depolarisation
It can cause many undesirable effects

Question 15

Ganglion blockers

Answer 15

Block muscle contractions therefore blocking skeletal muscle BY BLOCKING OF nicotine receptors
This can be dangerous because the diaphragm needs to be able to contract so therefore we need artificial ventilation to assist breathing

Question 16

Non depolarising agents

Answer 16

Can be long term, short term or intermediate
Eventually all the drugs will need to be metabolised in the liver and released from the kidney
If these organs are impaired then they can remain in the body longer and cause more effects

Question 17

Acetylcholine in muscle cells

Answer 17

Muscle cells cannot be repolarised so when acetylcholine binds to the receptor they cannot cause further depolarisation causing desensitisation
Phase 2 is consistently depolarised and cannot repolarise causing muscle relaxation

Question 18

Acetylcholinesterase

Answer 18

AChe main function is to hydrolyse acetylcholine in the blood
Causes increased skeletal muscle contraction
Has short, medium and irreversible duration

Question 19

Sympathetic and parasympathetic systems

Answer 19

Sympathetic pathway(adrenergic) uses norepinephrine neurotransmitter and parasympathetic uses acetylcholine

Question 20

Adrenaline

Answer 20

Adrenaline can cause vasoconstriction in vascular beds

There is alpha adrenaline receptor neuroadrenaline> adrenaline>isoproternal

Question 21

adrenoreceptors

Answer 21

Two subtypes for alpha adrenoreceptors
Three subtypes for beta adrenoreceptors
All use G proteins

Question 22

A1 adrenoreceptor

Answer 22

Activates phospholipase C increasing IP3 and DAG

Constriction of smooth muscle in blood vessel

Question 23

A2 adrenoreceptors

Answer 23

mainly expressed in the presynaptic terminal
Reduces cAMP
Inhibition of neurotransmitters
Decreased insulin secretion

Question 24

adrenoreceptor antagonist

Answer 24

Non selective can reduce blood pressure

Selective can cause hypertension

Question 25

B1 adrenoreceptors

Answer 25

Mainly expressed in the heart Use in heart failure which is when heart activity is reduced Increases cAMP Increases heart rate and contraction

Question 26

B2 adrenoreceptors

Answer 26

Increases cAMP | Relaxes smooth muscle in bronchi

Question 27

B3 andrenoreceptor

Answer 27

Exercise’s are mediated by B3 receptors Increased cAMP B3 have many clinical usage renin is a Chemical substance produced in the kidney and activated during exercise Can be used to correct irregular heart contraction and chest pain

Question 28

B adrenoreceptor antagonist

Answer 28

Decrease blood pressure and sympathetic output | B adrenoreceptor causes reduction of heart rate and reduces bronchoconstriction

Question 29

Selectivity in drugs

Answer 29

Ideal drug will be selective to a certain subtype beta 1 adrenoreceptor specific to slow heart rate Drugs are selective not specific

Question 30

Adrenergic neurotransmission

Answer 30

Processes in the synapse of somatic nerve terminal Localised effect on vasoconstriction)Noradrenaline CA has 3 neurotransmitters that is secreted at adrenal medulla into the blood and cause a widespread effect

Question 31

CA

Answer 31

Adrenaline, noradrenaline and dopamine secreted as a hormone to cause widespread effect

Question 32

synthesis of CA

Answer 32

Synthesis of CA uses multiple enzymes to catalyse the reaction First enzyme adds an hydroxyl group Next enzyme removes of carboxyl group Next enzyme adds a hydroxyl group on to form noradrenaline PNMT adds another carboxyl group The first enzyme called Tyrosine hydroxlase is red limiting step and is critical for all production of adrenaline

Question 33

Dopamine in CA

Answer 33

Dopamine is transported into the vesicle of nerve terminal by transporter Once in the vesicle it can form noradrenaline due to the presence of DBH enzyme

Question 34

Noradrenaline in CA

Answer 34

Noradrenaline is released via exocytosis calcium is required. Noradrenaline is released onto post synaptic adrenoreceptors Indirectly acting sympathomimetic amine promotes the release of noradrenaline Once noradrenaline is released into the synaptic cleft there can be re uptake and go back into the vesicle again

Question 35

CA stages

Answer 35

``` synthesis storage release interaction of adrenoreceptors on target organ and glands Degradation or re-uptake ```

Question 36

Reuptake of noradrenaline in CA

Answer 36

Uptake occurs in the nerve terminals and is transported into the vesicles via VMAT's

Question 37

Dales principle(outdated)

Answer 37

a given neuron contains and releases only one neurotransmitter and exerts the same functional effects at all of its termination sites.

Question 38

co transmission

Answer 38

Neurotransmission usually uses co transmission We know that released neurotransmitters can also act on presynaptic neurones causing pre synaptic modulation Neurotransmitter release can also vary during development and injury

Question 39

Neuromodulation

Answer 39

It is difficult to differentiate from neurotransmissions and neuromodulation Neuromodulation is usually slower Neuromodulation acts via second messenger system whereas neurotransmission acts via ligand gated ion channels

Question 40

NANC | Non-adrenergic and non cholinergic transmitters

Answer 40

Two types: Ganglionic transmission:serotonin, GABA and dopamine Post ganglionic terminal:Nitric oxide

Question 41

Presynaptic modulation

Answer 41

Usually inhibitory | Co transmitters can affect transmitter release

Question 42

post nerve terminal tissue

Answer 42

Activation of post nerve terminal tisssue cause biological response

Question 43

Homotropic auto inhibition

Answer 43

Pre synaptic auto receptor activation causes inhibition of neurotransmitter release in cholinergic and adrenergic

Question 44

hetrotropic presynaptic inhibition

Answer 44

Noradrenaline inhibits Ach in nerve terminals rELEASE neurotransmitter x can act on another nerve terminal which can inhibit neurotransmitter Y and works in the opposite direction

Question 45

Serotonin

Answer 45

Inhibits noradrenaline release and causes vasodilation and excitatory effect on eccentric neurones

Question 46

Post synaptic medators

Answer 46

Mediators modify excitability Mediator Y can also cause an individual effect by itself But when and X and y act together they cause a strong effect X and Y act on different tissues

Question 47

NPY

Answer 47

NPY enhances the function of noradrenaline by increasing calcium

Question 48

Co transmission of ATP and noradrenaline

Answer 48

Neuroadranaline and ATP are co stored in the vesicle at a ratio of 4:1 NA can also act on presynaptic a2 adrenoreceptor so GI coupled receptor can inhibit adynlayse cyclase inhibiting cAMP reducing calcium channel function reducing calcium

Question 49

ATP

Answer 49

Stored in synaptic vesicle at terminals Allows for fast transmission in autonomic ganglia Co transmitter with noradrenaline causes contraction in bladder

Question 50

Nitric oxide

Answer 50

Nitric oxide is synthesised from L-argine which is an amino acid cGMP increases the vasodilation in the lungs Sildenafil increases NO by inhibiting breakdown of cGMP(Localised effect) Can reduce blood pressure which can cardiovascular reflex response to reduce vascocontrisction