lect 2: cortisol

• Anterior pituitary hormones


  • ACTH
  • TSH
  • LH/FSH
  • GH
  • PRL
• Anterior pituitary hormones


  • ACTH
  • TSH
  • LH/FSH
  • GH
  • PRL
• Hypothalamic hormones


  • CRH
  • TRH
  • GnRH
  • GHRH
  • SS
  • DA
• Hypothalamic hormones


  • CRH
  • TRH
  • GnRH
  • GHRH
  • SS
  • DA
• Peripheral target tissues


  • Adrenal gland
  • Thyroid gland
  • Gonads
  • Liver and other
  • Breast
• Peripheral target tissues


  • Adrenal gland
  • Thyroid gland
  • Gonads
  • Liver and other
  • Breast
• Anatomy of the adrenal glands


  • Hormones secreted by the adrenal glands
  • Mineralocorticoid control and function
  • Glucocorticoid control and functions
  • Catecholamine control and functions
  • Stress responses
• Anatomy of the adrenal glands


  • Hormones secreted by the adrenal glands
  • Mineralocorticoid control and function
  • Glucocorticoid control and functions
  • Catecholamine control and functions
  • Stress responses
• Synthesis of adrenal cortex hormones

  1. Cholesterol

  2. Pregnenolone

  3. Sex steroid precursors: Androstenedione

  4. Mineralocorticoid: Aldosterone

  5. Glucocorticoids: Cortisol, Corticosterone
• Synthesis of adrenal cortex hormones

  1. Cholesterol

  2. Pregnenolone

  3. Sex steroid precursors: Androstenedione

  4. Mineralocorticoid: Aldosterone

  5. Glucocorticoids: Cortisol, Corticosterone
• Zona glomerulosa


  • Aldosterone synthesis
• Zona glomerulosa


  • Aldosterone synthesis
• Aldosterone


  Maintains fluid volume, acts on kidneys to increase sodium and water reabsorption, increases potassium secretion, increases blood pressure
• Aldosterone


  Maintains fluid volume, acts on kidneys to increase sodium and water reabsorption, increases potassium secretion, increases blood pressure
• Cell signalling of aldosterone

  1. Aldosterone binds mineralocorticoid receptors (MR)

  2. Activates hormone response elements (HRE)

  3. Increases epithelial sodium channels (ENaC) and Na/K-ATPase
• Cell signalling of aldosterone

  1. Aldosterone binds mineralocorticoid receptors (MR)

  2. Activates hormone response elements (HRE)

  3. Increases epithelial sodium channels (ENaC) and Na/K-ATPase
• Control of aldosterone release by the renin-angiotensin system


  Fluid volume restored
• Control of aldosterone release by the renin-angiotensin system


  Fluid volume restored
• Control of cortisol release

  1. Hypothalamic CRH stimulates ACTH release from pituitary

  2. ACTH acts through melanocortin (MC2) receptors to increase P450scc enzyme activity

  3. HPA axis under negative feedback control
• Control of cortisol release

  1. Hypothalamic CRH stimulates ACTH release from pituitary

  2. ACTH acts through melanocortin (MC2) receptors to increase P450scc enzyme activity

  3. HPA axis under negative feedback control
• Cortisol


  Important for survival during stress, can generate glucose in liver from other substrates
• Cortisol


  Important for survival during stress, can generate glucose in liver from other substrates
• Cortisol actions in the body

  • Metabolic effects
  • Cardiovascular effects
  • Immunosuppressive effects
  • Other effects
• Cortisol actions in the body

  • Metabolic effects
  • Cardiovascular effects
  • Immunosuppressive effects
  • Other effects
• Hypothalamic CRH stimulates the release of ACTH from the pituitary because ACTH is cleaved from the precursor pro-opiomelanocortin
• Hypothalamic CRH stimulates the release of ACTH from the pituitary because ACTH is cleaved from the precursor pro-opiomelanocortin
• Sympathetic control of the adrenal medulla

  • Cardiovascular effects of adrenaline
  • Metabolic effects of adrenaline
• Sympathetic control of the adrenal medulla

  • Cardiovascular effects of adrenaline
  • Metabolic effects of adrenaline
• Stress


  The sum of the biological reactions to any adverse stimulus, physical, mental or emotional, internal or external, that disturbs homeostasis
• Stress


  The sum of the biological reactions to any adverse stimulus, physical, mental or emotional, internal or external, that disturbs homeostasis
• Fight-or-flight response (acute stress response)


  • Associated with release of adrenaline from adrenal medulla
  • First stage of general adaptation syndrome regulating stress responses
• Fight-or-flight response (acute stress response)


  • Associated with release of adrenaline from adrenal medulla
  • First stage of general adaptation syndrome regulating stress responses
• Effects of cortisol during stress

  • Energy mobilization
  • Vascular changes
• Effects of cortisol during stress

  • Energy mobilization
  • Vascular changes
• Chronic stress increases cortisol
• Chronic stress increases cortisol