Hormones of the Endocrine system

Question 1

Melatonin humans

Answer 1

Inhibits steroidogenic activity of gonads, regulates circadian rhythms, influences the onset of puberty, body rhythms, and jet lag

Question 2

Melatonin animals

Answer 2

estrous cycles and seasonal breeding, controls changing skin color in reptiles and lower vertebrates.

Question 3

Growth Hormone

Answer 3

somatotropic hormone - stimulates liver and other organs to synthesize and secrete insulin-like growth factor, which in turn stimulates the division of progenitor cells located in growth plates and in skeletal muscles = body growth.

Question 4

TSH

Answer 4

Thyroid-stimulating hormone ; stimulates growth of thyroid epithelial cells; stimulates production and release of thyroglobulin and thyroid hormones.

Question 5

ACTH

Answer 5

Adrenocorticotrophic hormone - maintains and stimulates secretion of glucocorticoids and gonadocorticoids.

Question 6

Where is T3 released from?

Answer 6

Released from follicular cells in response to FSH secretion from the pars distalis of the anterior pituitary gland; metabolically active form.

Question 7

T3 Function

Answer 7

Stimulates cell and tissue metabolism, influences heat production, stimulates body growth and development (emphasis on nervous system).

Question 8

T4

Answer 8

Similar secretion mechanism and function as T3, but needs to be converted to T3 (metabolically active)

Question 9

Calcitonin

Answer 9

PTH antagonist; important calcium regulator in animals, less in humans, secreted in response to high blood calcium levels, inhibits osteoclast activity and stimulates calcium deposition in bones; produced by parafolicular cells of the thyroid

Question 10

PTH

Answer 10

Stimulates increase in blood calcium levels by: 1) increasing calcium uptake by kidneys, 2) increasing excretion of phosphate by the kidneys 3) conversion of 25- OH Vitamin D3 to hormonally active form 1,25 - (OH)2 Vitamin D3 4) Increases calcium and phosphate absorption in the small intestine.

Question 11

Aldosterone

Answer 11

1) Generated from Cholesterol 2) acts on principle cells of distal kidney tubules, gastric mucosa, salivary glands, and sweat glands where it stimulates Na+ reabsorption 3) Promotes excretion of K+ by the kidneys

Question 12

Cortisol

Answer 12

1) Overall increased blood glucose levels with decreased peripheral glucose utilization 2) Promotes oxidation of fatty acids 3) Promotes protein degradation for AA used in gluconeogenesis 4) glycogen synthesis in the liver

Question 13

Androstenedione

Answer 13

Promotes development of secondary sex characteristics..

Question 14

Epinephrine/nor-epinephrine

Answer 14

increased HR, pulse, BP, ; decreased blood flow to skin, digestive activity, and urine output; dilation of pupils and respiratory passages.

Question 15

glucagon

Answer 15

stimulates release of glucose into blood, mobilizes fats from fat cells, stimulates hepatic lipase, proteolysis, etc.

Question 16

Insulin

Answer 16

promotes uptake of glucose from blood; stimulates glycogenesis; promotes glycolysis in cells; stimulates protein synthesis.

Question 17

somatostatin (GH)

Answer 17

inhibits insulin and glucagon secretion and suppresses exocrine secretion of pancreas