Physio - Endocrine

Front 1

Write the steps for production of vitamin D3 (1,25 dihydrocholecalciferol)

Back 1

-7-dehydrocholesterol
- cholecalciferol (or may be present in diet)
- 25 hydroxycholecalciferol (in the liver)
- 1,25 dihydroxcholecalciferol ( in mitochondria of proximal tubules in kidneys)

It then circulates bound to alpha-globulins in plasma

Front 2

Vitamin D functions

Back 2

It increases calcium and phosphate availability for bone mineralization:
- intestines: more calcium binding proteins are formed => more calcium is reabsorbed
it also increases absorption of phosphate ions from intestine
- in kidneys: weak stimulatory effect on calcium reabsorption
- in bones: increases resorption of bone which provides calcium and phosphates from 'old' bones to mineralize 'new' bone (?).

Front 3

Name 4 hormones important in pregnancy?

Back 3

1. Human chorionic gonadotropin (HCG)
2. Estrogen
3. Progesterone
4. Human chorionic somatomammotropin (HCS)

Front 4

Function of progesterone?

Back 4

- maintains growth of endometrium
- stimulates tubal and endometrial gland secretion
- inhibits uterine contractions
- substrate of cortisol and aldosterone by the adrenal gland of the fetus
-participates in inhibition of maternal immune responses

Front 5

Functions of estrogen?

Back 5

- enhances growth of uterine myometrium
- growth of ductal system in breast
- enlargement of external genitalia
-relaxation & softening of pelvic ligaments and pubic symphysis
- increase of cholesterol uptake by placenta => increase of progesterone synthesis

Front 6

Functions of HCG ?

Back 6

- maintains function of corpus luteum
- stimulates thyroid hormone release
- stimulates testosterone production (in male fetuses) by leydig cells and dehydroepiandrosterone by the adrenal gland
- inhibits LH secretion by the mother

Front 7

Functions of HCS ? (human chorionic somatomammotropin)

Back 7

- anabolic effects
- lactogenic activity
- increases lipolysis
-directs maternal metabolism to maintain a constant flow of substances to the fetus

Front 8

State the physical (cardiovascular) changes that occur during pregnancy.

Back 8

1. increased pCO2 and progesterone increases ventilation
-ventilation is mostly increased by increasing the tidal volume (not ventilatory rate as much)
-relative overbreathing removes more CO2 ( pCO2 in pregnant women may be 31mmHg instead of 40mmHg as in nonpregnant women).
2. Increase cardiac output; by increasing SV and HR
3. Fall of blood pressure due to decrase in total peripheral resistance (placenta+vasodilation by progesterone)
4. Blood volume increases but hematocrit decreases (negative iron balance)
5. increased sensitivity and effects of renin-angiotensin system => sodium and water retention.

Front 9

Hormonal changes during pregnancy.

Back 9

1. Prolactin - synthesized by decidual pregnant uterus and maternal pituitary
- stimulates mammary glands to produce milk
-contributes to surfactant synthesis in fetal lungs
-suppreses reproductive function of mother during lactation
2. insulin sensitivity increases allowing a greater increase of glucose,amino acids to be absorbed by fetus
3.aldosterone increases
4. acth,cortisol,crh increase - maternal adipose tissue gain, mammary gland development
5.thyroid hormones increase,along with thyroid binding proteins