Summary Gr 12 LS (Endocrine system and homeostasis)

ENDOCRINE SYSTEM AND HOMEOSTASIS




ENDOCRINE GLANDS: ductless glands that release their
secretions (hormones) directly into the bloodstream.


HOMEOSTASIS: process of maintaining a constant, internal
environment


NEGATIVE FEEDBACK: mechanisms in the body that detect
changes/imbalances to the internal environment that then
motivate action to restore the balance. Hormones play most
important role in negative feedback


**Endocrine glands and the hormones they secrete:
1. Hypothalamus = ADH
2. Pituitary gland = Growth hormone, TSH, FSH, LH and
prolactin
3. Thyroid gland = thyroxin
4. Pancreas = insulin and glucagon
5. Adrenal gland = adrenalin and aldosterone
6. Ovaries = estrogen and progesterone
7. Testes = testosterone

, HORMONE FUNCTION


ADH Controls concentration of
water in the blood


Growth hormone Controls growth


TSH Stimulates thyroid gland


FSH Stimulate development of
follicle in ovary

LH Stimulates ovulation


Thyroxin Controls basic metabolic rate


Adrenalin Increases blood pressure and
heart rate, decreases blood
flow to digestive system

Aldosterone Regulates salt concentration
in the blood

Insulin Stimulates conversion of
glucose to glycogen

Glucagon Stimulates conversion of
glycogen to glucose

Testosterone(male only) Stimulates maturation of
sperm cells



Estrogen and Stimulate puberty in females,
progesterone(female only) help thicken endometrium