Physiology Flashcards
What change occurs to arterial pCO2 in pregnancy?
Reduced
What reduces arterial pCO2 geographically?
Altitude > 2500m
Effect of arterial pCO2 on cerebral blood flow?
Increased pCO2 increases cerebral blood flow
What is the effect of reduced arterial pCO2 on urine?
Reduced pCO2 —> increased blood pH —> more alkaline urine
How does pH affect calcium?
Acidosis favors release of ionized Ca
Alkalosis favors binding of Ca and Dec ionized Ca
Total Ca level unchanged
Where is somatostatin produced?
Delta cells of pancreas and hypothalamus (growth hormone inhibiting hormone)
What do pancreatic beta cells produce?
Insulin and amylin
What are the contractant molecules of the myometrium?
Oxytocin (produced by uterus)
Prostaglandins (F2alpha)
How do the contractant molecules of the myometrium stimulate contractility?
Oxytocin and prostaglandins act via G protein coupled receptors to activate phospholipase C which increases intracellular Ca2+ concentration and activation of myosin light chain kinase, and Ca2+/calmodulin dependent protein kinase
Positive feedback loop - oxytocin stimulates uterine prostaglandin synthesis and prostaglandins up regulate oxytocin receptor expression
What are the relaxant molecules of the myometrium?
NO, relaxin, progesterone, (prostacyclin)
What is the action of myometrium relaxants?
Via cAMP and cGMP, activate dependent protein kinases which dephosphorylate myosin light chain and limit contraction force
Progesterone also inhibits synthesis and action of oxytocin and prostaglandins and inhibits gap junctions
Causes of hypokalaemia
- Transcellular shifts - alkalosis, insulin, beta-agonists
- Renal losses - diuresis, DKA after therapy, Conn’s
- Extrarenal losses - diarrhoea, NG suction
- Decreased intake - malnutrition, alcoholism
How is insulin made?
Cleavage of C-peptide from peptide chain
What change in electrolytes is acidosis associated with?
Potassium retention and rise in chloride with maintenance of anion gap
Vertical transmission rate of Hep B?
?20
Cancer type associated with endometrioma?
Clear cell carcinoma
Changes to insulin and glucagon after protein rich meal?
Both increase
What can occur with silicone implant rupture?
Silicone granuloma with giant cells
When should amniocentesis be performed?
After 15+0/40
When should CVS be performed?
After 11+0/40 (and not before 10+0/40)
What is the newborn screening test for CF?
Immunoreactive trypsinogen in Guthrie
Which hormone is similar to oxytocin?
Vasopressin
What type of oestrogen predominates in menopause?
Estrone E1
What type of oestrogen predominates in fertile non-pregnant women?
Estradiol E2
