Hormone & Functions

Aldosterone

Promotes urinary reabsorption of Na+ and Cl- & increases water reabsorption via osmosis → reduces loss of water in urine, increase in BV & BP

Angiotensin II

Stimulates secretion of aldosterone → reduces loss of water in urine along with vasoconstriction (which promotes sodium retention and increases BV)

Atrial natriuretic peptide (ANP)

Promotes natriuresis, elevated urinary excretion of Na+ & Cl- accompanied by water → increases loss of water in urine

Antidiuretic hormone (ADH) aka vasopressin

Promotes insertion of water-channel proteins (aquaporin) into the membranes of cells in the collecting ducts of kidneys → water permeability of these cells increases & more water is reabsorbed → reduces loss of water in urine along with increasing BP by elevating BV

Epinephrine

A stress hormone from the adrenal medulla that is activated by the SNS (fast acting) & increases metabolic effects (increases lipolysis, substrate use, mobilization, glycogen breakdown)

Norepinephrine

A stress hormone from the adrenal medulla that is activated by the SNS (fast acting) that increased physiological effects (increase in HR/BP, pupil dilation, increase in blood flow to essential organs)

Cortisol

Stress hormone from the adrenal cortex (slow-acting) that helps gives the body more energy (increase in lipolysis, gluconeogenesis, protein breakdown) through metabolism

hGH, IGF

A stress hormone from the liver that promotes lipolysis & glycogensis

T3 & T4

A stress hormone from the thyroid that increases glucose use for ATP (glycolysis)

Gastrin

Secretes gastric juices, increases gastric motility, constricts lower esophageal sphincter and relaxes pyloric sphincter which is stimulated by food in the stomach/partially digested proteins/PNS

Cholecystokinin (CCK)

Secretes pancreatic juices, releases bile, gives feelings of satiety, inhibits HCI- and is stimulated by amino acids and FFA in the small intestine

Secretin

Secretes pancreatic juice, produces bile, enhances effects of CCK and is stimulated by acid in the small intestine

Somatostatin

Inhibits CCK/secretin/gastrin → decreases the rate of digestion & absorption and is stimulated by low pH in the stomach

ACh

Stimulates secretion of HCI, pepsinogen, gastrin & of pancreatic enzymes, inhibits somatostatin

(active in the cephalic stage)

Gastric inhibitory peptide (GIP)

Decreases stomach secretions, motility and emptying in the interstina phase

Hormones in the Interdigestive phase

Somatostatin (secreted)

Gastrin & HCI (inhibited)

Hormones in the cephalic phase

ACh (stimulates secretion of HCI, pepsinogen, gastrin & pancreatic enzymes)

Hormones in the gastric phase

Gastrin (secreted because of peptides and amino acids)

Hormones in the interstinal phase

CCK (secreted because of amino acids & peptides)

Gastric inhibitory peptide (GIP)

Secretin (secreted because of low pH)