1. The Pituitary Gland Posterior pituitary The hypothalamus significantly influences the pituitary gland The hypothalamus makes and releases the hormones of the posterior pituitary Hypothalamic releasing and inhibiting hormones are delivered to the anterior pituitary

2. Pituitary (Hypophysis) Anterior Pituitary – “adenohypophysis” Posterior Pituitary – “neurohypophysis”     Oxytocin Antidiuretic Hormone (ADH)

3.   Anterior Pituitary – synthesizes 6 hormones.       Growth Hormone (hGH) (also called Somatotropin) Adrenocorticotropic Hormone (ACTH) (also called corticotropin) Thyroid Stimulating Hormone (TSH) Follicle Stimulating Hormone (FSH) Luteinizing Hormone (LH) Prolactin (PRL)

4.    hGH – is the primary hormone that regulates overall body growth, also important in general metabolism. ACTH – stimulates cortisol secretion from the adrenal cortex (the stress hormone!). Also promotes growth of adrenal cortex. TSH – stimulates secretion of thyroid hormone and the growth of the thyroid gland. Important regulator of metabolic activity in the body.

5.    FSH – a) in females: stimulates growth and development of ovarian follicles, and promotes estrogen secretion. LH – a) in females: responsible for ovulation and for luteinization. Regulates estrogen and progesterone. PRL – enhances breast development and milk production in females. b) in males: it is required for sperm production. b) in males: stimulates interstitial cells (in testes) to secrete testosterone. * called interstitial cell stimulating hormone (ICSH)

6. Normal Growth Growth hormone and other hormones An adequate diet Absence of stress Genetics

7. Growth Hormone Severe hGH deficiency leads to dwarfism Oversecretion of hGH in children leads to giantism Oversecretion of hGH in adults leads to acromegaly

8. The cortisol connection The Hypothalamus-Pituitary-Adrenal Axis (HPA)

9. Circadian Rhythm of Cortisol Secretion

10. Cortisol Promotes gluconeogenesis Breakdown of skeletal muscle proteins Enhances lipolysis (prevents glucose use) Suppresses the immune system Permissive – needed for NE vasoconstriction Response to stressors – protective?

11. Hypercortisolism Adrenal tumor that secretes cortisol Pituitary tumor that secretes ACTH e.g., Cushing’s disease (syndrome) ↑ glucose and ↓ protein Loss of muscle mass Characteristic fat deposits

12. Hypocortisolism e.g. Addison’s disease Hyposecretion of all adrenal steroid hormones Autoimmune destruction of adrenal cortex ↓ glucose (hypoglycemia) Poor response to stress Lack of permissive action