- The two adrenal glands are pyramid shaped organs that sit on top of the kidney.
- Each gland consists of two parts : inner medulla, outer cortex.
- The adrenal medulla produces two hormones which are also known as catecholamines : epinephrine (adrenaline) and norepinephrine (noradrenline)
- These hormones are similar to substances released by the sympathetic nervous system, therefore not essential to life.
- Control the "Fight or Flight" situation.
- Epinephrine (80%) - increases blood glucose levels, increases rate and cardiac contractions, constricts blood vessels, and stimulates the release of ACTH from the pituitary : ACTH will stimulate adrenal cortex to release glucocorticoids.
- Norepinephrine (20%) - increases both heart rate and force of cardiac contractions, vasoconstricts blood vessels throughout the body.
- The adrenal cortex secretes corticosteroids (mineralocorticoids and glucocorticoids) and androgens which are essential to life.
- The release of mineralocorticoids is controlled by renin (enzyme).
- Mineralocorticoids play a vital role in body fluid regulation. (renin-angiotensin-aldosterone system)
- The glucocorticoids include cortisol and cortisone.
- Glucocorticoids are released in time of stress.
- These hormones affect carbohydrate metabolism by regulating glucose use in body tissues, mobilizing fatty acids from fatty tissues.
NORMAL VS FLIGHT & FIGHT RESPONSE
DISORDERS OF ADRENAL CORTEX
TYPES OF DISORDERS
- Disorders of adrenal cortex can result in excessive/reduced production of glucocorticoids, mineralocorticoids and androgens.
- 1 major condition of hyposecretion/adrenal insufficiency : Addison's Disease
- 3 major conditions of adrenocorticol hyperfuntion are :
b) Conn's Syndrome or aldosteronism (aldosterone excess)
c) Congenital Adrenal Hyperplasia (adrenogenital syndrome, androgen excess)
REFERENCES
- http://www.nlm.nih.gov/medlineplus/adrenalglanddisorders.html
- http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/endocrinology/diseases-of-the-adrenal-gland/
- Brunner & Suddarth's (2010). Assessment and Management of Patients With Endocrine Disorders,Medical-Surgical Nursing Text Book. 42(8), 1275-1287
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