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
What type of oestrogen is produced by placenta?
Estriol E3
What type of oestrogen is produced by fetal liver?
E4 estetrol
Where are oestrogens produced?
Ovary
Liver
Adrenal glands
Adipose tissue
Breast tissue
Placenta
What is progesterone a precursor for?
Aldosterone, cortisol, androstenedione, testosterone
Where is progesterone produced?
Corpus luteum, tested, adrenals, placenta
Daily calcium requirement of fetus in third trimester?
200mg
Most frequent cause of pathological hyperprolactinaemia?
Drugs
Which cell type congegrates in cervix to release collagenase?
Neutrophils
At what gestation is physiological dilution anaemia the greatest?
32/40
Hb concentration of newborn?
165-175 g/L
Most important buffer in interstitial space?
Bicarbonate
Normal adult dietary requirement of calcium?
700mg
Ratio of plasma testosterone in pregnancy?
1% free, 19% albumin bound, 80% SHBG bound
Placental mechanism for uptake of glucose?
Facilitated diffusion
Fetal Ca requirement in third trimester?
200mg
What is the distance between z-lines in muscle?
Sarcomere
What is the length of myosin in muscle?
A-band
Beta-hCG peaks at?
8-12 weeks
Which 3 hormones are structurally similar?
Prolactin, GH, hPL
Which 4 hormones are structurally similar?
FSH, LH, hCG, TSH
Which hormones stimulate breast ductal morphogenesis in pregnancy?
Oestrogen and GH
Which hormones stimulate breast alveolar morphogenesis in pregnancy?
Progesterone, prolactin, hPL
Most important anion in urine?
Chloride
Cytokine involved in OHSS?
VEGF
Hormone predictor of fertility and androgenic?
AMH
Main difference between transudate and exudate?
High specific gravity
Genetic variants of LH reported in individuals with PCOS?
Variants of LH beta subunit
Structure of progesterone?
C21
Oliguria definition
<400mL urine in 24h (but >100mL)
Anuria definition
<100mL urine/24h
Number of carbons of androgens?
C19
Number of carbons of estrogens?
C18
Time to produce sperm?
64 days
Time for follicular maturation up to ovulation?
80 days