Endocrine System and Hormones

Question 1

Endocrine System

Answer 1

Complex network of glands and organs that release/use hormones
- Nervous system allows organisms to quickly adapt to changes in the environment while endocrine system maintains control over a long time (can regulate and sustain development for years)

Question 2

Hormones

Answer 2

Chemicals that affect cells in other body parts by speeding up or slowing down bodily processes
- Endocrine hormones produced in glands and secreted directly into bloodstream
- Type and # of hormone receptors varies from cell to cell

Question 3

Types of Hormones: Steroids

Answer 3

Made up of cholesterol (ex. sex hormones)

Question 4

Steroids Action

Answer 4

1. Diffuses into capillaries, then into interstitial fluid, then into target cell
2. Binds to receptor molecule in cytoplasm
3. Hormone-receptor complex moves to nucleus where it attaches to DNA at complementary shape, activating a gene to produce a specific protein

Question 5

Types of Hormones: Protein Hormones

Answer 5

Made up of chains of amino acids of varying length (ex. GH and insulin)

Question 6

Protein Hormones Action

Answer 6

1. Bind to specific receptor molecule at cell membrane (too big so cannot diffuse through)
2. Hormone-receptor complex activates production of enzyme adenylyl cyclase which causes cell to convert ATP to cAMP
3. cAMP acts as a messenger, activating enzymes in the cytoplasm to perform their normal functions

Question 7

Pituitary Gland

Answer 7

“Master” that controls other endocrine glands; small, sac-like structure connected by a stalk to the hypothalamus - produces and stores hormones; stimulated by hypothalamus to release hormones via nerve impulses –> can also inhibit secretion of hormones

Question 8

Posterior Pituitary Gland

Answer 8

Does not produce its own hormones, stores hormones made by the hypothalamus (ex. ADH and oxytocin)

Question 9

Anterior Pituitary Gland

Answer 9

Produces its own hormones, which generally regulate other glands (ex. TSH, FSH, LH, MSH, GH, ACTH, prolactin)

Question 10

Glands in Body

Answer 10

Pineal Gland, Hypothalamus, Pituitary Gland, Thyroid Gland, Parathyroid Gland, Thymus, Adrenal Gland, Pancreas, Testes, Ovaries