The adrenal cortex (outer layers) secretes 3 groups of:
The adrenal medulla (central portion of gland) secretes
catecholamines – norepinephrine and epinephrine
There are three histologically distinct layers of the suprarenal cortex, each synthesizing a characteristic “family” of steroid hormones.
Z glomerulosa cells synthesize
Synthesize mineralocorticoids, principally aldosterone
under fibrous capsule (C) in rounded clusters separated by fibrous trabeculae from capsule
Zona fasciculata cells synthesize / secrete
Synthesize / secrete glucocorticoids, primarily cortisol
arranged in parallel cords or plates (typically 2 cells thick) separated by capillaries parallel to the plates
Z reticularis cells - smallest of the secretory cells of the adrenal cortex secrete:
Synthesize and secrete adrenal androgens (androstenedione and DHEA) – these are weak androgens compared to testosterone, but the only androgen source in females
Arranged in irregular branching network cellular cords surrounded by blood vessels and connective tissue
Addison’s disease –
Destruction of the adrenal cortex (autoimmune, tuberculosis)
All adrenal steroids are affected – mineralocorticoids, glucocorticoids and androgens –mineralocorticoids and glucocorticoids are necessary for life
ACTH - secreting adenoma of the anterior pituitary
High ACTH → drives cortisol and androgen synthesis/release
Cushing’s syndrome –
Functional tumor of the adrenal cortex OR administration of glucocorticoids in pharmacological doses
(High cortisol → negative feedback inhibition of pituitary ACTH release)
Adrenal cortical adenoma
– solitary circumscribed mass of cortical cells
-usually a mixture of cortical cell types
– can be one cell type: Conn’s Syndrome = adenoma of glomerulosa cells → hyperaldosteronemia
There are two types of adrenal medullary cells –
- most synthesize / secrete epinephrine (E)
- a smaller population secretes norepinephrine (NE).
These catecholamines are packaged and stored in secretory granules.
Tumors of suprarenal medullary cells.
They produce symptoms related to excess catecholamines (“fight or flight”) including tachycardia / palpitations, elevated blood pressure (sometimes dangerously elevated), chest pain, sweating, constipation, fine tremor, and anxiety.