Physiology Flashcards
Exchangeable bone calcium is mediated by
Osteocytes
Extracellular Ca levels are
2.2 to 2.6 mmol /L
Ca imp in how many processes mainly and they are
4 processes
Nerve and muscle excitation
Muscle contraction
Clotting
Secretions
Parathormone is
A 84 amino acids polypeptide
Initial phase of Ca release from bone by PTH action is?
Longer term, release is by?
Osteocytes releasing exchangeable bone calcium
Osteoclast activity
PTH and VitD site of action on kidney
Pth .. DCT
Vit D… PCT
Vit D conversion is stimulated by
PThH and low phosphate
Not calcium levels directly
Calcitonin site of secretion
Parafollicullar cells of thyroid
Action of PTH, Vit D and calicitonin on phosphate in kidney
- PTH.. Reduces Phospate renal absorption
- 1, 25 vit D…. Increases Phospate renal absorption
- Calcitonin: Decreases Phospate renal absorption
2 and 3 have same action on Calcium in kidney
1 has opposite in kidney
Congenital cause of hypoparathyroidism?
Di George syndrome
Which one is rare and common between hypo and hyperparathyroidism
Hypoparathyroidism is rare while hyper is common
Differentiate between tertiary and secondary hyperparathyroidism
Both have high pth
Secondary has low or normal calcium
tertiary has high calcium
Mnemonic for hypercalcemia
Stones, bones, abdominal growns, and psychiatric overtones
Only hyperparathyroidism with low or normal calcium levels
Secondary hyperparathyroidism
Al dosterone acts on
Distal nephron
Perform Na resorption and release of K
Deficiency Causes hyponatraemia and hyper kalaemia
Types of cells based on regenerative capacity
Labile(skin, esophagus,vagina and intestine)
Stable(liver, renal tubular epithelium)
Permanent(nerve, striated muscle cells and cardiac cells
2 functions of vWF
- Platelet adhesion
- it binds and stabilizes the procoagulant protein factor VIII
Treatment of VWD
- desmopressin (DDAVP)
- recombinant vWF
- vWF/factor VIII (vWF/FVIII) concentrates
ECG of Hypokalaemia
U waves
Small or absent T waves (occasionally inversion)
Prolonged PR interval
ST depression
Long QT interval
Retrograde ejaculation
Damage to upper urinary centre in the bladder
Auto regulation of blood flow to brain is at what CPP??
60 to 160 mm Hg
Timing of loss of consciousness and irreversible damage after interrupted blood flow to brain
3 sec
2 to 3 mins for latter
Cerebral perfusion pressure in severe head injuries depends upon
ICP
CPP= MAP-ICP
At what pressure below which O2 levels start affecting cerebral flow
8kpa