Catecholamines are neurotransmitters that regulate various central nervous system functions, but are also hormones that regulate cardiovascular and respiratory function, secretions and muscle contraction.įigure 11: Multiple systemic effects of cortisol Cortisol excess (or Cushing Syndrome)Įtiology: most commonly exogenous (iatrogenic or due to supraphysiologic exposure to glucocorticoids) rarely endogenous.Androgens also serve as precursors of estrogens. Androgens are important for sexual development and reproduction in both males and females.Aldosterone regulates water retention, Na and K balance and body's blood pressure. Aldosterone secretion is under the control of the renin-angiotensin system (not under the control of the brain).

Cortisol actions affect almost every body system (Figure 11 below). Cortisol production itself also shuts down the system at the pituitary and hypothalamic levels (negative feedback inhibition).

Cortisol secretion is under the control of the hypothalamic CRH and pituitary ACTH.

See figure 10 below, where arrows represent enzymes that convert one substrate to another.įigure 10: Main pathways of adrenal steriodogenesis Adrenal steroidogenesis includes three main pathways, leading to cortisol, aldosterone and androgen synthesis, with androgens eventually being aromatized (converted to estrogens). Adrenal glandareas and zones with respective hormones synthesizedĬholesterol (low-density lipoprotein or LDL) is the precursor for adrenal steroidogenesis. The medulla serves as the site of catecholamine, metanephrine and normetanephrine synthesis.įigure 9. The cortex is further divided in 3 zones (zona glomerulosa or site of aldosterone synthesis, zona fasciculata or site of cortisol synthesis and zona reticularis or site of androgen synthesis).

The adrenal gland is divided into twodistinct areas, the cortex and the medulla.

Adrenal production