Physio 3200 - Exam 5 (Dr. Zhao)

What do endocrine glands secrete and where?

Hormones into the bloodstream (no ducts)

Endocrine vs nervous system (speed + duration)?

Endocrine = slow, long-lasting; Nervous = fast, short-lived

Endocrine vs exocrine glands?

Endocrine = no ducts, blood; Exocrine = ducts, surfaces

What amino acids are amine hormones derived from?

Tyrosine

Examples of catecholamines?

Epinephrine, norepinephrine, dopamine

Where are the amine catecholamines produced?

Medulla

Where is the amine catecholamine dopamine released?

Hypothalamus

Steps of peptide hormone synthesis?

Preprohormone → Prohormone → Hormone

How are peptide hormones released?

Exocytosis

What are steroid hormones made from?

Cholesterol

What structures produces steroid hormones?

Adrenal cortex, gonads, & skin

Which hormones travel unbound in blood?

Peptides and catecholamines

Which hormones require carrier proteins?

Steroid and thyroid hormones

Which hormone form is biologically active?

Free hormone

Where are receptors for peptide hormones?

Cell membrane

Where are receptors for steroid hormones?

Inside the cell

What is up-regulation?

Increase in receptor number due to low hormone levels

What is down-regulation?

Decrease in receptors due to high hormone levels

What is permissiveness?

One hormone enhances another’s effect

What triggers PTH release?

Low blood Ca²⁺

Effects of PTH?

↑ Ca²⁺ via kidney, intestine, and bone

What stops PTH secretion?

High Ca²⁺ (negative feedback)

Within the ovaries, what enzyme converts testosterone to estradiol?

aromatase