Ch. 11 Endocrine Pt. 1

What’s the difference between Endocrine System & Nervous System?

Endocrine system functions more slowly, BUT effects last longer

Exocrine glands vs. Endocrine glands

Exocrine glands→secretions are thru ducts to surface of skin/GI tract (sweat & sebaceous glands)

Endocrine glands→ductless & secrete hormones into interstitial fluid→blood

What are the 3 types of hormones?

1) amines

2) peptides & proteins

3) steroids

characteristics of amine hormones

1) hormones derived from single amino acids(tyrosine or tryptophan)

2) water-soluble so dissolve in plasma of the blood

3) secreted by adrenal medulla, thyroid, pineal glands

characteristics of peptide hormones

examples?

-chains of amino acids

ex// ADH & insulin

characteristics of protein hormones

examples?

-long polypeptides (>100) bound to 1 or more Carbohydrate groups

ex// FSH, LH, TSH, hCG

what are free hormones?

examples?

-hormones that are water-soluble & dissolve in plasma of blood

ex// catecholamines & peptides

characteristics of steroid hormones

examples?

-lipids derived from cholesterol

-non-polar

ex// testosterone, estradiol, progesterone

How do steroid & thyroid hormones circulate in the blood?

they attach to plasma proteins BC they are not soluble

How is a steroid synthesized?

basically a GPCR/cAMP pathway

cAMP activates→PKA protein→phosphoproteins form→cholesterol creates steroid

How does a steroid hormone leave the cell?

simple diffusion out the cell→blood

What is the permissive effect of a hormone?

examples?

-a hormone increases the activity of a 2nd hormone

ex1// estrogen primes progesterone during menstrual cycle

ex2// thyroid hormone increases adrenergenic receptors→increases epinephrine activity

What is an antagonistic effect of a hormone?

example?

-a hormone decreases activity of 2nd hormone

ex// Insulin(beta cells) decreases blood glucose levels BUT also inhibits glucagon(alpha cells) (which increases blood glucose)

Up-regulation vs. Down-regulation of hormones

Up-regulation→increase in hormone receptors BC low hormone levels(high sensitivity)

Down-regulation→decrease in hormone receptors BC high hormone levels (low sensitivity)

what is a tropic hormone?

example?

a hormone that control the secretion of another hormone

ex// TSH(thyroid stimulating hormone)

hyposecretion vs. hypersecretion

endocrine disorders

hypo secretion→too little hormone secreted

hyper secretion→to much hormone secreted

Example of a hyporesponsiveness endocrine disorder?

Type II Diabetes

-target cells don’t respond to insulin→body makes more insulin BUT blood glucose levels stay high still(hyperglycemia)