The adrenal glands are located above the upper end of each kidney. The adrenal medulla makes up the center of each gland, and produces epinephrine and norepinephrine. The adrenal cortex makes up the outer layer of the gland and produces glucocorticoids, gonadocorticoids, and mineralocorticoids. 

Chromaffin cells are found in the adrenal medulla (adrenal glands are located above the kidneys.) Chromaffin cells are regulated by preganglionic sympathetic fibers and release catecholamines, epinephrine (adrenaline) and norepinephrine (noradrenaline) into systemic circulation. The secreted epinephrine and norepinephrine play an important role in the "fight or flight" response elicited by the sympathetic nervous system. The zona glomerulosa is responsible for secreting aldosterone, the zona fasciculata is responsible for secreting cortisol (and a small amount of androgens) and the zona reticularis is primarily responsible for secreting androgens. 

The adrenal glands, located superior to the kidneys, are responsible for secreting epinephrine, norepinephrine, and cortisol in order to regulate the body's stress, or "fight-or-flight," response. The thyroid gland secretes thyroid hormones and calcitonin. The pancreas secretes digestive enzymes and hormones that regulate blood sugar. The ovaries and testes secrete sex hormones that regulate sexual development.

The adrenal medulla is a specialized ganglion of the sympathetic nervous system. The adrenal medulla's preganglionic fibers synapse directly onto chromaffin cells located within the adrenal medulla. This causes the chromaffin cells to secrete epinephrine (80%) and norepinephrine (20%) into the circulation.

A Pheochromocytoma is a tumor of the adrenal medulla that secretes excessive amounts of catecholamines.

The three layers of the adrenal cortex are the zona glomerulosa, zona fasciculata, and zona reticularis. The hormones produced in each layer are mineralcorticoids, glucocorticoids, and androgens, respectively.

The common way to help remember the layers of the adrenal cortex from superficial to deep is the acronym "GFR" and the respective hormones produced are "salt, sugar, and sex" hormones. Salt hormones=mineralocorticoids, sugar hormone=glucocorticoids, and sex hormones are the androgens.

Insulin is made in the beta cells of the pancreas in response to ATP from glucose metabolism. Insulin inhibits glucagon release by alpha cells of the pancreas in a negative feedback mechanism to maintain constant blood glucose levels.

Insulin has several anabolic effects, including increased glucose transport in skeletal muscle and adipose tissue, increased glycogen synthesis and storage, increased triglyceride storage, increased protein synthesis in muscles, and increased cellular uptake of potassium and amino acids. 

Glycogen is made by pancreatic alpha cells and is secreted in response to hypoglycemia, resulting in glycogenolysis and gluconeogenesis to increase circulating blood glucose levels.

Bile is composed of bile salts, phospholipids, cholesterol, bilirubin, water and ions. Bile functions in the emulsification and absorption of lipids and fat-soluble vitamins, as well as cholesterol excretion. Bile also has antimicrobial activity via membrane disruption. In the duodenum, bile will orient hydrophobic regions around a lipid micelle and provide hydrophilic interaction with the surrounding environment. The micelle can then be transported to the lacteals for introduction to the lymphatic system and absorption.

Bile is not involved in protein digestion; this is the function of proteases, such as trypsin.

Pancreatic amylase is responsible for starch digestion in the duodenum. Salivary amylase also aids in this process, and is introduced early in digestion in the mouth.

Proteases like trypsin are responsible for cleaving proteins. Carboxypeptidase is also involved in specific protein digestion. Lipases are involved in lipid and fat digestion. All of these enzymes are introduced in the duodenum of the small intestine, where the majority of chemical digestion occurs.

The road back to homeostasis starts with cells in the kidneys detecting decreased blood volume. The kidneys then secrete renin. Renin activates angiotensinogen (produced by the liver) in the blood. The renin-activated peptide is called angiotensin I and when it passes through the pulmonary circuit, it is converted to angiotensin II by angiotensin converting enzyme (ACE). Angiotensin II is a vasoconstrictor and it causes the adrenal glands to secrete aldosterone. Aldosterone acts directly on the kidneys to conserve sodium, which stimulates the release of antidiuretic hormone from the posterior pituitary, and thereby increase the blood volume and pressure.

The pancreas can secrete glucagon or insulin to either increase or decrease blood sugar, respectively, to achieve normal blood glucose levels, which are between . The other glands listed do not secrete hormones that directly affect the blood sugar. Note that cortisol, released from the adrenal cortex, increases blood sugar levels.