week 3 L4-regulation of calcium phosphate

Question 1

recommended calcium daily intake

Answer 1

1000mg

Question 2

calcium distribution

Answer 2

99% in skeleton and teeth

intracellular and extracellular

Question 3

importance of calcium

Answer 3

muscle contraction, bone strength, intracellular 2nd messenger, intracellular co-enzyme, blood coagulation factor

Question 4

importance of phosphate

Answer 4

high energy compound, 2nd messenger, fundamental molecules component

Question 5

relationship between calcium and phosphate

and why

Answer 5

extracellular calcium and extracellular phosphate are inversely proportional
both regulated by the same hormone

Question 6

serum calcium forms

Answer 6

ionised unbound
bound to plasma proteins
associated with inorganic anions

Question 7

which form of serum calcium is active

Answer 7

ionised unbound free calcium is the biologically active component

Question 8

increase serum calcium of phosphate

Answer 8

parathyroid hormone (PTH)
vitamin D
homeostasis action of kidneys, bone and gut

Question 9

Decrease serum calcium and phosphate

Answer 9

calcitonin- no negative effect if parafollicular cells are removed by thyroidectomy

Question 10

sources of vitamin D

Answer 10

Ergocalciferol vitamin D2- Diet

cholecalciferol vitamin D3- sunshine on skin

Question 11

parathyroid hormone PTH secretion

Answer 11

large precursor pre-pro-PTH cleaved to PTH
G protein coupled calcium receptor on chief cells detect change in conc.
PTH secreted inversely prop to Calcium ( more calcium less PTH)
NB calcium ion presence inhibit release of PTH

Question 12

calcitonin

Answer 12

secreted from the parafollicular cells

reduced serum calcium but no effect if removed.

Question 13

abnormal calcium metabolism

Answer 13

hypercalcaemia and hypocalcaemia

Question 14

action potential generation affected by calcium level

Answer 14

hypercalcaemia-Ca2+ blocks Na+ influx therefore less membrane excitability
hypocalcaemia- greater Na+ influx and more excitable memebrane

Question 15

hypocalcaemia signs and sypmtoms

Answer 15

CAT go numb-paraesthesia, convulsions, arrrthmias, tetany

Chvostek’s sign and Trousseau’s sign

Question 16

Chvostek’s sign

Answer 16

facial never just below zygomatic arch twitch when tapped

Question 17

Trousseau’s sign

Answer 17

inflation BP for minutes= carpopedal spasm

muscle can contract but cannot relax

Question 18

causes of hypocalcaemia

Answer 18

low PTH levels

vit D deficiency

Question 19

causes of vit D deficiency

Answer 19

malabsorption of diet deficiency
inadequate skin exposure
liver disease
renal disease 
Vit D receptor defects

Question 20

Vit D deficiency

Answer 20

lack of bone mineralisation aka soft bones

children rickets and adults osteomalacia

Question 21

hypercalcaemia signs and symtoms

Answer 21

stones-renal effect
abdominal moans-GI effects, anorexia nausea constipation
psychic groans- CNS effects-fatigue, depression, impaired concentration,coma or altered mentation

Question 22

causes of hypercalcaemia

Answer 22

primary hyperthyroidism -due to adenoma
malignancy
vitamin D excess