BIO202ch17

Question 1

Homeostasis

Answer 1

• receptor
• control center (brain)
• effectors (correct)
  stable maintained by feedback loop

Question 2

negative feedback

Answer 2

causes corrective mechanisms to stop.

temperature regulation/sweating

Question 3

positive feedback

Answer 3

causes corrective mechanisms to continue
child birth/oxytocin during labor
major cut

Question 4

what are amplitude modulated signals;

Answer 4

endocrine

Question 5

what are frequency-modulated signals;

Answer 5

nervous system

Question 6

intercellular chemical signals;

Answer 6

cell to communicate other cells

• neurotransmitters
• neuromodulators
• hormones

Question 7

neurohormones =

Answer 7

norepinephrine, ADH, oxytocin

Question 8

hormones =

Answer 8

a substance/chemical messengers secreted by an endocrine tissue “into the blood” circulation that act on a target tissue to produce a specific response.

Question 9

autocrine =

Answer 9

local, same cell type

prostaglandin (lipid compounds from fatty acids

Question 10

paracrine =

Answer 10

para=around, two close to each other
paracrine=cell affect other cell type locally without transported in blood
- somatostatin (=GHIH)

Question 11

tropic =

Answer 11

tropic hormones regulate activity of various other endocrine glands
- pheromone

Question 12

chemical structure

membrane bound receptor:

Answer 12

• amino acid derivative (small)=epinephrine, norepinephrine, TH, melatonin
• peptide (group of amino acid/larger)=TRH, ADH, oxytocin, glucagon, calcitonin
• protein (very big)=GH, prolactin, insulin

Question 13

chemical structure

inside cell;

Answer 13

• steroid=estrogen, progesterone, testosterone, cortisol, aldosterone
• eicosanoids (lipids derived from cell membranes) =prostaglandin, thromboxane

Question 14

hormone secretion rate

Answer 14

most hormone are not at constant rate

• pulsatile secretion
• circadian (daily cycle) rhythm of secretion

Question 15

patterns of hormone regulation:

Answer 15

• humoral (liquid)
  plasma glucose changes insulin release
  plasma Ca changes PTH release
• neural (faster)
  epinephrine/norepinephrine from adrenal medulla
• hormonal (stimuli of one endocrine gland secreted by another)=anterior pituitary is regulated by Releasing (RH) and Inhibiting (IH) from the hypothalamus

Question 16

long half-life

Answer 16

fat/cholesterol soluble molecule

Question 17

short half-life

Answer 17

water soluble
outside cell work through G-protein
rapid onset and short duration

Question 18

Hormones are eliminated by:

Answer 18

• liver = enzymatic degradation(can’t hold anymore)

- kidney =filter everything & hormone, return necessary

Question 19

Down-regulation

Answer 19

ignore message

- decreased number of receptors by fatigue or after long stimulation

Question 20

Up-regulation

Answer 20

respond quickly

• stimulus increases the rate of receptor synthesis
• number of receptors increases

Question 21

Hormone receptors

Membrane-bound receptors bind to:

Answer 21

water soluble (protein) or large-molecular-weight hormones

Question 22

Hormone receptors

intracellular receptors bind to:

Answer 22

lipid-soluble (hydrophobic) hormones, receptor is inside cell, do not go to G-protein

Question 23

Hormone receptors

activate G-proteins that activate Second-messenger system:

Answer 23

water soluble (outside) hormones

• glucagon bind to glucagon receptor
• epinephrine

Question 24

Steroid hormone & TH direct gene activation:

Answer 24

direct (steroid-inside) synthesis/make of proteins

- aldosterone

Question 25

cascade effect = one action produce larger G-proteins

Answer 25

1. hormone+receptor (at plasma membrane)
2. G-proteins
3. adenylate cyclase
4. cAMP
5. protein kinase enzymes