Presentation on theme: "The Pituitary Gland Posterior pituitary The hypothalamus significantly influences the pituitary gland The hypothalamus makes and releases the hormones."— Presentation transcript:
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
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.
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)
7ft 7in tall, died at age 22. Thyroid Goiter. Adrenal disorders in Females: Hirsutism (male hair) Oligomenorrhea (infrequent menstruation) Deepening of voice Hypertrophy of clitoris (resemble penis) Pituitary Gland has enormous impact on entire Body.
Negative Feedback Loop of Hypothalmic-Adenohypophysis and the Thyroid Gland
Normal Growth Growth hormone and other hormones An adequate diet Absence of stress Genetics
Cholesterol Vitamin D Cortisone Glucocorticoids Mineralcorticoids Bile Salts Steroid Hormones (testosterone, estrogen, progesterone)
Wow, what a “Life Saver”.
Growth Hormone Severe hGH deficiency leads to dwarfism Over secretion of hGH in children leads to gigantism Over secretion of hGH in adults leads to acromegaly
Pathway of Growth Hormone Control
The Cortisol Connection The Hypothalamus-Pituitary-Adrenal Axis (HPA)
CRH = Corticotropin Releasing Hormone ACTH = Adrenocorticotropic Hormone The many functions of cortisol in the body:
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?
Circadian Rhythm of Cortisol Secretion
Hyper-Cortisolism Adrenal tumor that ↑ cortisol Pituitary tumor that ↑ ACTH e.g., Cushing’s Disease ↑ glucose and ↓ protein Loss of muscle mass Characteristic fat deposits
Hypo-Cortisolism e.g. Addison’s Disease Under secretion of adrenal steroid hormones Autoimmune destruction of adrenal cortex ↓ glucose (hypoglycemia) Poor response to stress Lack of vasoconstriction (permissive NE action)
Symptoms and Clinical Signs Fatigue and muscle weakness. Low Blood Pressure (Orthostatic Hypotension). Headache, sweating, joint and muscle pains. Increased Melanocyte-Stimulating Hormone (MSH).