Adrenal Gland Part 1

Where are the adrenal glands located?

Adjacent to the kidneys.

What does the term adrenal mean?

Ad = near; renal = kidneys.

What are the two major regions of the adrenal gland?

Adrenal cortex and adrenal medulla.

What is the embryologic origin of the adrenal cortex?

Mesoderm.

What is the embryologic origin of the adrenal medulla?

Neuroectoderm (neural crest cells).

What are the three zones of the adrenal cortex?

Zona glomerulosa, zona fasciculata, and zona reticularis.

Which adrenal cortical zone is the outermost and thinnest?

Zona glomerulosa.

Which adrenal cortical zone is the middle and thickest layer?

Zona fasciculata.

Which adrenal cortical zone is the innermost layer?

Zona reticularis.

What are the cells of the adrenal cortex called?

Corticocytes.

What are the secretory cells of the adrenal medulla called?

Chromaffin cells.

What are adrenocorticosteroids?

Hormones produced by the adrenal cortex.

What type of hormones are adrenocorticosteroids?

Steroid hormones.

What are the four major classes of hormones produced by the adrenal cortex?

Glucocorticoids, mineralocorticoids, androgens, and estrogens.

Which adrenal cortical hormones are produced in the greatest amounts?

Glucocorticoids and mineralocorticoids.

What is the precursor of all adrenocorticosteroids?

Cholesterol.

How is cholesterol delivered to adrenal cortical cells?

By LDL.

Are adrenal steroid hormones stored before secretion?

No.

How are adrenal steroid hormones produced?

They are synthesized de novo when needed.

What are the major glucocorticoids?

Cortisol and corticosterone.

Which glucocorticoid predominates in humans, horses, pigs, sheep, dogs, and cats?

Cortisol.

Which glucocorticoid predominates in rabbits, mice, and rats?

Corticosterone.

What are glucocorticoids considered in physiology?

Major permissive hormones.

What does permissive hormone mean?

A hormone that enhances the actions of other hormones.

What is the primary glucocorticoid in dogs?

Cortisol.

What is the primary glucocorticoid in cats?

Cortisol.

What is the primary glucocorticoid in horses?

Cortisol.

What is the primary glucocorticoid in pigs?

Cortisol.

What is the primary glucocorticoid in sheep?

Cortisol.

What is the primary glucocorticoid in rabbits?

Corticosterone.

What is the primary glucocorticoid in rats?

Corticosterone.

What is the primary glucocorticoid in mice?

Corticosterone.

What is the primary function of glucocorticoids?

Influence physiological processes in most body tissues.

What effect do glucocorticoids have on appetite?

They stimulate the appetite center in the hypothalamus.

What condition may develop when glucocorticoid levels are excessive?

Polyphagia.

What does polyphagia mean?

Excessive appetite or excessive food intake.

What are mineralocorticoids?

Steroid hormones that regulate salt and water balance.

What is the major mineralocorticoid hormone?

Aldosterone.

Which adrenal cortical hormone regulates sodium and potassium balance?

Aldosterone.

What is the primary physiological action of aldosterone?

Increases sodium reabsorption and potassium excretion.

In which organ does aldosterone primarily act?

The kidneys.

Which adrenal cortical hormone is responsible for maintaining extracellular fluid volume?

Aldosterone.