Lecture 47

Question 1

Receptors for hormones are of what affinity and why?

Answer 1

high because hormone levels are low in the body

Question 2

Endocrine glands are made from what type of tissue?

Answer 2

ductless epithelial

Question 3

Secretions by the endocrine glands are effected by what factors?

Answer 3

ions/nutrient level changes, neurotransmitters (indirect)

Question 4

What are neuroendocrine/neurosensory cells?

Answer 4

cells that secrete directly into the bloodstream instead of working across a synapse

Question 5

Steroids are controlled by what mechanism?

Answer 5

intracellular receptors

Question 6

Peptides are controlled by

Answer 6

heterotrimeric G, RTKs

Question 7

Autocrine/paracrine hormones act in what way?

Answer 7

only locally

Question 8

Cytokines can act

Answer 8

systemically and locally (colony stimulating factors)

Question 9

Steroids are lipophilic, so they cannot be stored

Answer 9

in vesicles for calcium medicated release - they are produced and diffused on demand and directly diffused into the bloodstream

Question 10

How are steroids and peptides transported?

Answer 10

peptides are dissolved in the plasma, steroids are bound to plasma proteins and very few are free

Question 11

What is significant about a free hormone?

Answer 11

it is the only kind that can cross the cell membrane to bind with its specific intracellular receptor - this binding limits clearance by kidneys

Question 12

Water soluble hormones include

Answer 12

peptides and catacholamines

Question 13

Metabolic clearance rate

Answer 13

rate of clearance/conc of clearance (in mL)

Question 14

Which hormone works the fastest to cause a release of fatty acids?

Answer 14

epinephrine combined with thyroid hormone - epinephrine follows, thyroid last