Biochemistry

Question 1

Anterior pituitary produces

Answer 1

FSH, prolactin, TSH, ACTH, LH, GH (Fresh Pituitary Tastes Almost Like Guinness)

Question 2

Posteior pituitary produces

Answer 2

Oxytocin, ADH

Question 3

Thiazide diuretics act on

Answer 3

Early distal tubule

Question 4

Thiazide diuretics MoA

Answer 4

Inhibits NaCl reabsorption (so excretion of water increased)

Question 5

CCK is produced by

Answer 5

I cells in duodenum/jejunum

Question 6

CCK causes

Answer 6

Increased bile production, GB contraction, increased pancreatic secretion, decreased gastric emptying, decreased gastric acid production

Question 7

Dopamine effects on cardiac muscle

Answer 7

Acts on B1 receptors to increase contractility

Question 8

Hepcidin MoA

Answer 8

Regulates iron haemostasis; INHIBITS iron absorption (so conditions requiring more Fe will cause hepcidin suppression)

Question 9

Adenosine MoA

Answer 9

Stimulates A1-adenosine receptors to open potassium channels, causing K efflux and hyperpolarising cells in the AV node

Question 10

Muscle contraction steps

Answer 10

Calcium released from sarcoplasmic reticulum, binds troponin, exposes binding sites (moves tropomyosin), allows myosin cross-bridges to form with actin, myosin head “flexes” and ATP released as ADP and Pi (more ATP needed to repeat the process)

Question 11

CRP production is stimulated by

Answer 11

IL-6

Question 12

Ferritin is

Answer 12

Storage protein for iron/acute-phase inflammatory marker (may have low Fe but NORMAL ferritin in infection)

Question 13

Transferrin

Answer 13

Facilitates storage/transport of iron in plasma (so low Fe and increased transferrin = TIBC)

Question 14

Trypsin

Answer 14

Secreted by the pancreas; breaks down proteins

Question 15

Intrinsic factor produced by

Answer 15

Parietal cells

Question 16

Intrinsic factor function

Answer 16

B12 absorption

Question 17

Pepsinogen produced by

Answer 17

Chief cells

Question 18

Vitamin K-dependent clotting factors are

Answer 18

II, VII, IX, X

Question 19

Megaloblastic anaemia caused by

Answer 19

Most commonly B12/folate deficiency - reduced DNA synthesis

Question 20

SAN action potential

Answer 20

Resting potential -60, threshold -40 due to “leaky” Na channels, opens voltage-gated Ca channels tor raise potential to +20, opens voltage-gated K channnels to drop back to -60

Question 21

Loop diuretic MoA

Answer 21

Inhibits Na/K/Cl transporter (out of thick ascending limb, into interstitium)