Endocrine system Flashcards
Positive Feedback
Process by which a hormone acts to directly or indirectly cause increased secretion of a hormone
Negative Feedback
Process by which a hormone acts to directly or indirectly inhibit further secretion of the hormone of interest
Thyroxine
Hormone that stimulates metabolic activities
Produced by parafollicular cells of the thyroid
Calcitonin
Hormone that lowers blood Calcium
Works antagonistically to PTH
Produced by thyroid
Two Thyroid Hormones
Calcitonin and Thyroxine
Testosterone
Hormone that stimulates sex characteristics in men
Secreted in the testes
Estrogen
Secreted in ovaries
Induces release of LH in menstrual cycle
With progresterone, helps maintain the endometrium during pregnancy
Progresterone
Hormone that regulates the menstrual cycle and pregnancy
Three Main Sex Hormones
Progresterone, Estrogen and Testosterone
Parathyroid Hormone (PTH)
Increases serum concentrations of calcium
Targets SKELETON - cause digestion of bone matrix and release of calcium. KIDNEYS- causes increased reabsorption of Ca from the forming urine and returns it to the blood. SMALL INTESTINE- cause increased absorption of Ca by the intesitinal mucosal cells
Glucagon
Hormone that stimulates conversion of glycogen into glucose
Raises blood sugar
Produced by pancreas
Insulin
Hormone that is secreted in response to high blood glucose levels to promote glycogen formation
Lowers blood sugar
Produced by pancreas
Two Hormones of the Pancreas
Insulin and Glucagon
Epinephrine
Hormone that raises blood glucose level, increases metabolic activity
Produced by the adrenal gland
Cortisol
Distress hormone released in responses to physiological challenges
Produced by the adrenal gland