Endocrine Overview

Question 1

Describe polar ligands

Answer 1

Polar ligands are made in advance and stored in membrane-bound vesicles which are exocytosed into the bloodstream as soluble particles with short half-lives where they interact with membrane-bound receptors that perform signal transduction from the cell surface (i.e. these dont enter the cell)

Question 2

Describe non-polar ligands

Answer 2

Ligands that are made in the cell as needed and are relased via non-vesicle dependent passive diffusion into the bloodstream as carrier-bound non-soluble particles with long half-lives that enter their respective target cells

Question 3

What is the difference between the general mechanism of action of polar and non-polar ligands?

Question 4

What types of hormones are polar?

Answer 4

peptides and amines

Question 5

What are steroid hormones all derived from?

Answer 5

cholesterol

Question 6

What types of hormones are non-polar?

Answer 6

-steroids

Question 7

What are the amine hormones?

Answer 7

melatonin and serotonin

catecholamines

thyroid hormones

Question 8

What are melatonin and serotonin derived from?

Answer 8

tryptophan

Question 9

What are catecholamines and thyroid hormones derived from?

Answer 9

tyrosine

Question 10

Note about thyroid hormones

Answer 10

These are synthesized like peptide hormones, but behave like steroid hormones once released in the sense that they are made in advance in vesicles because their pre-cursors are polar but they are modified to non-polar forms for release and, thus, are relased via simple diffision, and bound to carrier proteins, have long-half-lives, and induce new protein synthesis (aka non-polar behavior)

Note that cateholamines act 100% like polar molecules

Question 11

What hormones are secreted from the posterior lobe of the pituitary gland? Where are they made?

Answer 11

oxytocin and ADH (synthesized from the hypothalamus)

Question 12

What hormones are secreted from the anterior lobe of the pituitary gland?

Answer 12

ACTH

TSH

GH

Prolactin

FSH and LH

These hormones are made here!

Question 13

What are the hormones secreted from the anterior lobe of the pituitary regulated by?

Answer 13

hormones from the hypothalamus

Question 14

Where does melatonin come from?

Answer 14

pineal gland

Question 15

What hormones are secreted from the thyroid gland?

Answer 15

thyroxine and tri-idothyronine

calcitonin

Question 16

What hormones does the heart secrete?

Answer 16

naturetic peptide, which decreases BP

Question 17

What hormones does the pancreas secrete and what are their function?

Answer 17

Insulin- decreases blood glucose

Glucagon- increases blood glucose

Question 18

What hormones are secreted by the adrenal cortex?

Answer 18

cortisol and aldosterone

Question 19

What hormones are secreted by the adrenal medulla?

Answer 19

epinephrine and norephinephrine

Question 20

What are the half-lives of amines, peptide hormones, steroids and proteins, and thyroid hormones?

Answer 20

amines- 2-3 min

peptides- 4-40 min

steroids and peptides- 4-170 min

thyroid- 1-7 days