L5 adrenal cortex Flashcards
Where are the catecholamines (norepinephrine and epinephrine) secreted from?
inner adrenal medulla
where are adrenal steroids sex steroids such as progestogens like progesterone, potent androgens like testosterone, and estrogens like estradiol) secreted from?
the outer adrenal cortex
where are mineralcorticoids such as aldosterone synthesised?
outer zona glomerulosa of the adrenal cortex
where are glucocorticoids such as hydrocortisone synthesised?
middle zona fasciculata.Glucocorticoids are not stored in the adrenal gland are synthesised under the influence circulating Adrenocorticotropic hormone (ACTH)secretion from the anterior pituitary, released in a pulsatile fashion. ACTH secretion itself is also pulsatile & is regulated by Corticotropin-releasing hormone (CRH) (also known as corticotropin-releasing factor (CRF) release from the hypothalamus, and by Antidiuretic hormone (ADH) released from the posterior pituitary gland.The release of both ACTH and CRF in turn, is reflexively inhibited by the ensuing rising concentration, of Glucocorticoids in the blood
what do glucocorticoids do?
Glucocorticoids (e.g. Hydrocortisone/cortisol)affect carbohydrate and protein metabolism as well as regulating host defence mechanisms.
what do mineralocorticoids do?
Mineralocorticoids (e.g. aldosterone) Regulate water and electrolyte balance.
How do glucocorticoids affect carbohydrates?
Decreased uptake and utilisation of glucose accompanied by increased gluconeogenesis; causing tendency for hyperglycaemia.
How do glucocorticoids affect proteins?
Increase catabolism, reducedanabolism - Can lead to muscle wasting.
how do glucocorticoids affect fat?
a redistribution of fat (e.g. Cushing syndrome)
what affects does cortisol have on carbohydrate metabolism?
cortisol opposes insulin. Antagonizes the effects of insulin on cellular uptake of glucose
Stimulates glycogenolysis
Stimulates hepatic gluconeogenesis.
Apart from carbohydrate metabolism, what affects does cortisol have on the body?
Cortisol stimulates lipolysis and mobilization of fatty acids, partially by potentiating the effects of growth hormone and the catecholamines.
In excessive concentrations cortisol causes fat synthesis and deposition in novel anatomical sites, most notably the face, the trunk and the intrascapular region of the shoulders.
In the liver, cortisol stimulatesamino acid uptake leading toenhanced gluconeogenesis.
In the periphery it inhibits aminoacid uptake and protein synthesis,resulting in a net loss of skeletalprotein.
what does acth do?
increasing production and release of cortisol from the adrenal gland.
