TOPIC C: ANS

Question 1

What form of communication does noradrenaline rely on

Answer 1

Synaptic communication

Question 2

What form of communication does adrenaline rely on

Answer 2

Endocrine communication

Question 3

Outline the synthesis of noradrenaline

Answer 3

Occurs in adrenal medulla and neurons

Tyrosine transported into cell and converted to DOPA by tyrosine hydroxylase

DOPA converted to dopamine by DOPA decarboxylase

Dopamine put in storage vesicles by VMAT protein and then converted to NA by beta hydroxylase in vesicle

Question 4

Explain termination of NA by reuptake

Answer 4

Reuptake of NA into neurons is most important and immediate effect

Reuptaker protein

NA that doesn’t go back into storage is metabolised by monoamine oxidase (MAO)

Question 5

Outline the synthesis of adrenaline

Answer 5

Occurs in adrenal medulla

Adrenaline is synthesised from noradrenaline by PNMT enzyme

Question 6

What is a beta 1 receptor usually involved in

Answer 6

force and rate of contraction

Question 7

What is a beta 2 receptor usually involved in

Answer 7

relaxation

Question 8

Where are beta 1 receptors found

Answer 8

heart
liver
skeletal muscle

Question 9

Where are beta 2 receptors found

Answer 9

lungs (bronchial smooth muscle)

blood vessel beds in skeletal musclw

Question 10

Where are beta 3 receptors found

Answer 10

White and Brown adipose tissue

Skeletal muscle

Question 11

What beta receptors are involved in sympathetic energy metabolism. And what do they do

Answer 11

1: Glycogenolysis in liver and muscle by activating glycogen phosphorylase and inhibiting glycogen synthase by cAMP pathway. Uptake of glucose into muscle
3: Lipolysis in WAT. Thermogenesis in BAT. By cAMP pathway

Question 12

How does BAT thermogenesis by the beta 3 receptor work

Answer 12

Uncoupling protein 1 (UCP-1) generates heat instead of ATP in mitochondria.

cAMP pathway encourages lipolysis and fatty acids are used to produce heat

Question 13

What beta receptor is involved in cardiovascular function. And what does it do

Answer 13

beta 1 increases:

force of contraction,
HR,
AV conduction,
CO
SV

Question 14

What would a beta 1 antagonist do with respect to exercise

Answer 14

decrease exercise tolerance due to beta 1 involvement

Question 15

What beta receptor is involved in bronchiolar function. And what does it do

Answer 15

beta 2

Circulating catecholamines like adrenaline cause bronchodilation

Question 16

What is a side effect of beta 2 agonists used for bronchodilation

Answer 16

muscle tremor due to beta 2 receptors also being in skeletal muscle

Question 17

What is a side effect of beta 2 antagonists used for bronchodilation

Answer 17

bronchospasm

worsening of asthma in asthmatics

Question 18

What beta receptor is involved in sympathetic skeletal muscle function. And what does it do

Answer 18

beta 2

vasodilation

Question 19

what are examples of a non selective agonist and antagonist of beta receptors

Answer 19

agonist: isoprenaline
antagonist: propranolol

Question 20

what are examples of selective agonists and antagonists of beta 1 and 2 receptors

Answer 20

1 agonist: dobutamine

1 antagonist: metoprolol

2 agonist: salbutamol, clenbuterol

2 antagonist: —

Question 21

Expected effects of beta receptor agonists

Answer 21

increased HR and force

Increased blood flow to skeletal muscle

Widening of bronchi

Enhanced muscle tremor

Question 22

Expected effects of beta receptor antagonists

Answer 22

Fatigue

Cold extremities

Narrowing of bronchi

Steadiness of skeletal muscle

Question 23

What the main effects on the body due to sympathetic nerve stimulation

Answer 23

Mydriasis (eye dilation)

Bronchodilation

Tachycardia

Decreased GI motility

Question 24

Define pharmacokinetics

Answer 24

How the body interacts with the drug

Question 25

Define pharmacodynamics

Answer 25

How drugs act to alter body function

Question 26

What are the roles of the liver

Answer 26

distribution of nutrients metabolism excretion destruction of toxic substances storage of iron, vitamins

Question 27

What are active and pro drugs

Answer 27

Active drugs are drugs which can act straight away on the body. Pro drugs need to be metabolised first to a different product which is active.

Question 28

What are the 4 steps of the pharmacokinetic phase

Answer 28

absorption distribution metabolism excretion

Question 29

Why do drugs need to have components of both lipid and water solubility

Answer 29

cross lipid membranes to get into cells cross water filled spaces to be distributed

Question 30

What are 4 ways of administering a drug

Answer 30

inhalation intranasal topical (skin, eye, ear) Intravenous

Question 31

Explain the thiopentone example

Answer 31

intravenous drug used as an induction anaesthetic. anaesthesia reached within 20 seconds due to intravenous meaning reaches brain quicker lasts only for 5-10 minutes not by being metabolised but by being redistributed into other tissues

Question 32

What does the liver do in metabolism of drugs

Answer 32

converts lipid soluble to water soluble to be excreted in urine (called bio-transformation)

Question 33

Explain phase 1 of drug metabolism in the liver

Answer 33

makes drug more polar by adding reactive group and permitting conjugation cytochrome P450 family of enzymes

Question 34

Explain phase 2 of drug metabolism in the liver

Answer 34

Conjugates drug and adds endogenous compound to increase polarity UDP glucuronosyl transferase

Question 35

Outline cytochrome P450 family of enzymes

Answer 35

drug metabolising enzymes in liver and small intestines also involved in biosynthesis and degradation of endogenous substances CYP3A4 common enzyme

Question 36

Factors affecting drug metabolism

Answer 36

``` Genetic variability Race and ethnicity Age Gender Diet Disease Drug interactions ```

Question 37

Toxicity of paracetamol example

Answer 37

Normally metabolised by glucuronide sulfates, small percentage converted to NAPQI (toxic) NAPQI detoxified by glutathione when glutathione is depleted, NAPQI reacts with thiol groups on liver cell membranes Body needs a lot of glucuronide sulfates and glutathione to process paracetamol safely.