Endocrine system

Question 1

Main glands involved in Endocrine system (2)
- their functions

Answer 1

Hypothalamus
- secretes hormones, that regulate P. gland

Pituitary gland (P. gland)
- secretes hormones, that stimulate/inhibit other glands

Question 2

2 examples of glands that P. gland stimulates/ inhibits

Answer 2

• thyroid
• adrenal

Question 3

3 types of glands, differences, examples

Answer 3

ENDOcrine glands
- secrete hormones directly into surrounding interstitial fluid, diffuses into blood
- eg. P. gland, thyroid, adrenal

EXOcrine glands
- secrete into ducts
- eg sweat, mucous, digestive glands

ENDO+EXOcrine glands
- pancreas

Question 4

3 Hormones functions

Answer 4

• control growth and development
• regulate activity of reproductive system
• help establish circadian rhythms

Question 5

what process occurs during low conc of hormones

Answer 5

UP regulation

Question 6

2 TYPES of hormones, meaning

Answer 6

PARAcrine
- local, dont circulate

AUTOcrine
- act on same cell that secretes them

Question 7

Lipid soluble hormones- what, eg

Answer 7

• freely circulate in plasma (eg steroid, thyroid hormones)
• bind to receptors WITHIN target cell
• various target cells respond differently to same hormones (eg insulin)

Question 8

WATER soluble hormones- what, eg

Answer 8

• circulate cell ONLY when BOUND TO TRANSPORT PROTEIN (found on membrane of target cell) <- 1st messenger
• eg: protein hormones
• 2nd messenger= enzyme produced in cell after hor-receptor complex activated (eg cAMP)

Question 9

Cell response to hormones eg

Answer 9

• muscle contraction
• metabolic rate change
• change in permeability of membrane
• new molecule synthesis

Question 10

Target cell response to hormone depends on, 2 eg

Answer 10

• blood hor. conc
• other hor. influence
• etc, ..

Question 11

what is a synergistic effect in hormones

Answer 11

• when hormones work better with 2nd hormone present to assist
• eg in milk production (oestrogen, cortisol, oxytocin, prolactin)

Question 12

what is an antagonistic effect in hormones

Answer 12

• when some hormones oppose actin of others
• eg blood sugar control (insulin & glucagon)

Question 13

Hor. secretion regulated by 3 general examples

Answer 13

• NS signals
• Chem. changes in blood
• other hor.

Question 14

most hormones operate on negative/ positive feedback loop?

Answer 14

NEGATIVE

Question 15

example of hor. that operates on positive feedback loop

Answer 15

stretching of cervix

Question 16

what connects hypothalamus and P gland

Answer 16

infundibulum
- “a funnel-shaped cavity or structure. The hollow stalk which connects the hypothalamus and the posterior pituitary gland.”

Question 17

4 things the hypothalamus+ P glan control

Answer 17

growth, development, metabolism, homeostasis

Question 18

what is the HYPOPHYSEAL portal system

Answer 18

• middle section of two sets of vessels, where blood mixes
• allows communication between hypo. and P gland (via hormones)
• connects nervous and endocrine system