Physiology

Question 1

To which receptor does dobutamine bind

Answer 1

Sympathomimetic both alpha and beta agonist but mainly beta 1

Question 2

ECG features of hypokalaemia

Answer 2

U waves
Small or absent T waves
Prolonged PR interval
ST depression
long QT interval

Question 3

Which which cells is histamine released in the stomach to cause secretion of acid

Answer 3

Enterochromaffin cells

Question 4

Stomach cells and secretions

Answer 4

Parietal cells - HCL, Ca, Ma, Mg, Intrinsic factor
Chief cells - Pepsinogen
Surface mucosal cells - mucus and bicarbonate

Question 5

I hat is thr maximal site of sodium absorption on the GI tract

Answer 5

Jejunum

Question 6

Pancreatic secretions

Answer 6

Enzymes - Acinar cells
Water - Ductal Cells

Question 7

Factors affecting renin sections

Answer 7

Stimulating - hypotension, hyponatraemia, sympathetic stimulation, catecholamines, erect posture

Reducing - beta blockers, NSAIDs

Question 8

Side effects of neostigmine

Answer 8

Sweating, bradycardia, salivation

Occurs due to activation of the muscsrinic receptors of the autonomic nervous system

Question 9

What effects does storing blood have on handling oxygen

Answer 9

Stored blood has less 2,3 DPG and therefore a higher affinity for oxygen. This reduces its ability to release it in metabolic tissue

Question 10

Oxygen and the Bohr effect

Answer 10

Question 11

What causes secretion of adrenaline from the adrenal medulla

Answer 11

Acetylcholine from the pregangkionic sympathetic fibres of the splanchnic nerves

Cause chromaffin cells release contents via exocytosis

Question 12

Where is CCK released from

Answer 12

I cells of the duodenum

Question 13

From which amino acid are catecholamines produced

Answer 13

Tyrosine

Question 14

What is the greatest stimulus for gastric acid production

Answer 14

Histamine

Question 15

Cardiovascular changes in pregnancy

Answer 15

Decreased SVR
Increased plasma volume
Increased red cell volume
Increased heart rate
Ventricular distension
Raised BP
Capillary bed dilatation

Question 16

Where is most dietary iron absorbed

Answer 16

Proximal small bowel (duodenum and jejunum) by divalent transports (as Fe2+) and bound as ferritin

Question 17

Which drug increases gastric emptying post vagotomy

Answer 17

Erythromycin

Metocloprimide effects mediated by the vagus

Question 18

What is the primary substrate for bile acids

Answer 18

Cholesterol- primary bile salts are choleys and chenodeoxycholate

Question 19

What does noradrenaline primarily bind to

Answer 19

Alpha 1

Alpha 1& 2 vasoconstriction
Beta 1 increased cardiac contractual ITU and HR
Beta 2 vasodilatation
Delta 1 renal and spleen vasodilatation
Delta 2 inhibits release of noradrenaline

Question 20

Adrenaline affects on the heart

Answer 20

Cardiac affects mediated by beta 1 receptors.

Coronary arteries which have beta 2 receptors are unaffected

Question 21

Half life of albumin

Answer 21

20days

Question 22

Action of CCK

Answer 22

Increases pancreatic enzyme release, increases pancreatic bicarbonate release, gallbladder contraction, inhibits gastric emptying

Question 23

Area of GI tract with highest levels of potassium

Answer 23

Rectum

The rectum has the potential to generate secretions rich in potassium. This is the rationale behind administration of resins for hyperkalaemia and the development of hypokalaemia in patients with villous adenoma of the rectum.

Question 24

Factors affecting renin

Answer 24

Stimulating
Factors stimulating renin secretion
• Hypotension causing reduced renal perfusion
• Hyponatraemia
• Sympathetic nerve stimulation
• Catecholamines
• Erect posture

Factors reducing renin secretion
• Drugs: beta-blockers, NSAIDs

Question 25

Protein C

Answer 25

It is linked to the action of factor V and VIll, not factor II. Protein C and S are natural anticoagulant proteins. Protein C is synthesised in the liver and protein S is synthesised by the liver, endothelial cells, magakaryocytes and Leydig cells. Their synthesis is a vitamin K dependent process. Protein C and S bind to form a complex that inactivates factor Va and Villa. Resistance to activated protein C is otherwise known as factor V Leiden and confers an increased risk of thromboembolic events.

Question 26

Increased rates of gastric emptying

Answer 26

Chloramphenicol has no effect on gastric emptying. Ondansetron slows gastric emptying slightly. Metoclopramide increases the rate of gastric emptying but its effe are mediated via the vagus nerve.

Question 27

Nerve fibres

Answer 27

ow transmission of mechanothermal stimuli is transmitted via C fibres. a fibres transmit information relating to motor proprioception, A B fibres transmit such and pressure and B fires are autonomic fibres.