Calcium Homeostasis is part of the Endocrine Physiology section of Physiology. Practise 24 exam-style MCQs for NEET PG, FMGE, INI-CET and NEET SS, each with the correct answer and a detailed explanation.
Parathormone action at TRPV5, renal 1-alpha hydroxylation, hepatic 25-hydroxylation and the tetany of hypocalcaemia and alkalosis anchor these Calcium Homeostasis MCQs — high-yield NEET PG and FMGE endocrinology.
Three major organs in calcium homeostasis are: Skin Liver Kidney Reference: Ganong, 25th edition page no.377
TETANY is seen in: Alkalosis Hypocalcemia Hypomagnesemia During hyperventilation CO2 will be washed out. Greater amount of the calcium will bind with plasma proteins (albumin). Therefore patients with respiratory alkalosis are more susceptible for hypocalamic tetany. While in acidosis, less calcium bind with plasma proteins so more free calcium
PTH acts directly in renal tubules to increase calcium resorption from distal tubules through TRPV5 Reference: Ganong, 25th edition/page no.379
25-hydroxycholecalciferol is converted in the cells of the proximal tubules of the kidneys to the active product called 1,25-dihydroxycholecalciferol or calcitriol The responsible for this hydroxylation is called 1 α -Hydroxylase Reference: Ganong, 25th edition page no.378
Parathormone hormone increases calcium in the blood and decreases phosphate in the blood therefore. It cause resorption of the bone and also increases calcium absorption from the kidney while inhibits phosphate absorption from the kidney causing phosphate excretion Reference: Ganong's Review of Medical Physiology, 25th Edition, Page Number-379.
Kidney also expresses another important enzyme called 24-Hydroxylase whose action forms the inactive metabolite 24, 25-dihydroxyvitamin D This inactive form conversion is facilitated during increased serum calcium levels Reference: Ganong, 25th edition/page no.378
Glucocorticoids decreases plasma Ca 2+ levels by inhibiting osteoclasts Reference: Ganong, 25th edition page no.383
25 hydroxylation occurs in liver In the liver, Vitamin D 3 is 25-hydroxylated by an enzyme called 25-Hydroxylase Reference: Ganong, 25th edition page no.377
Parathormone action at TRPV5, renal 1-alpha hydroxylation, hepatic 25-hydroxylation and the tetany of hypocalcaemia and alkalosis anchor these Calcium Homeostasis MCQs — high-yield NEET PG and FMGE endocrinology.
MedLadder includes 24 curated MCQs for Calcium Homeostasis under Physiology (Endocrine Physiology), covering NEET PG, FMGE, INI-CET and NEET SS preparation.
