Adrenal lec

• Adrenal Gland

  Produces the steroid hormones

  Pathologic conditions are associated to blood pressure and electrolyte balance

  Located above and medial of kidneys
• Adrenal Gland

  • Adrenal Cortex (Outer)

  Adrenal Medulla (Inner)
• Adrenal Cortex


  Derived from mesenchymal cells

  Yellow (gross sectioning)
• Adrenal Medulla


  Arises from neural crest cells

  Dark Mahogany
• Adrenal Function


  Axons that passes through the cortex release neurotransmitters (e.g. cathecolamine) to modulate blood flow, cell growth, function

  Medullary projections into the cortex also release neuropeptidase (vasoactive inhibitory peptide, adrenomedullin and ANP)
• Adrenal Cortex Zones


  • Zona Glomerulosa

  Zona Fasciculata

  Zona Reticularis
• Zona Glomerulosa

  Produces Mineralocorticoid (Aldosterone)

  Responsible for Na retention
• Zona Fasciculata

  Produces Glucocorticoid (Cortisol)

  Responsible for Glucose Metabolism and Blood pressure
• Zona Reticularis

  Produces Androgen (DHEAS)

  Sulfate DHEA to DHEAS
• Adrenal Cortex Steroidogenesis

  Cholesterol -> Pregnenolone -> Progesterone -> 17-OH Progesterone -> 11-deoxycortisol -> Cortisol

  Cholesterol -> Pregnenolone -> 17-OH Pregnenolone -> DHEA -> Androstenedione -> Testosterone

  Cholesterol -> Pregnenolone -> Progesterone -> 11-deoxycorticosterone -> Corticosterone -> Aldosterone
• Hypothalamus releases CRH, Pituitary releases ACTH

  ACTH stimulates Adrenal Cortex to produce Glucocorticoids (Cortisol)
• Renin-Angiotensin-Aldosterone System


  Renin -> Angiotensin I -> Angiotensin II -> Adrenal Cortex releases Aldosterone

  Aldosterone increases Na retention and K excretion by the kidneys, increasing blood volume and pressure
• Hypoaldosteronism


  Causes hyponatremia, hyperkalemia, and renal wasting
• Hyperaldosteronism


  Causes hypernatremia, hypokalemia, hypertension, and metabolic alkalosis
• Adrenal Insufficiency (Addison's Disease)


  Causes hypoglycemia, weight loss, and hypotension
• Hypercortisolism


  Causes hyperglycemia, central obesity, and hypertension
• Congenital Adrenal Hyperplasia


  Caused by 21-hydroxylase deficiency, leads to increased 17a-OH progesterone and decreased cortisol
• Congenital Adrenal Hyperplasia


  • ↓ 21-hydroxylase
• Congenital Adrenal Hyperplasia


  • ↑ 17a-OH progesterone
  • ↓cortisol
• Addison's Disease (Adrenal Insufficiency)


  • 1° (↓Adrenal cortex)
  • 2° (↓ACTH)
• Hyperaldosteronism


  • 1° (↓renin), 2° (↑ renin)
  • Pseudo- (Bartter, Gitelman)
• Addison's Disease (Adrenal Insufficiency)


  • 1° (↓ Adrenal cortex)
  • 2(ACTH)
• Congenital Adrenal Hyperplasia


  • ↑ 17a-OH progesterone
  • ↓cortisol
  • ↓aldosterone, ↓ cortisol
• Cushing syndrome (Hypercortisolism)


  • ↑ CRH, ↑ ACTH (68%),
  • ↑ Cortisol (17%)
• Adrenal Cortex


  • Main steroid: DHEA & DHEAS (androgen precursor)
  • Main regulator: Not Known
• Not Known -R-Zone → DHEA(S)
• Androgen excess

  • Virilization in women and children
  • Gonadal dysfunction & infertility in men and women
• Adrenal Cortex

  • Main steroid: DHEA & DHEAS (androgen precursor)
• Cortex

  90% of adrenal gland
• G Salt

  15% of adrenal gland
• F Sugar

  75% of adrenal gland
• Medulla

  10% of adrenal gland
• R Sex

  10% of adrenal gland
• Biosynthesis

  1. Phenylalanine-Tyrosine-DOPA-Dopamine

  2. Dopamine-NE-EPI
• Location

  Medulla, Chromaffin Cells
• Hormone

  Catecholamines (Norepinephrine & Epinephrine)
• VMAT

  Vesicle monoamine transporters
• Normal Ratio

  NE:EPI = 9:1
• Medulla Chromaffin Cells


  • Atypical sympathetic ganglion
  • First responders to stress "fight or flight" response
• Diagnosis of Adrenal Disorders

  • Hyperaldosteronism
  • Adrenal Insufficiency
  • Hypercortisolism
  • Pheochromocytoma