the pituitary gland posterior pituitary the hypothalamus significantly influences the pituitary...
TRANSCRIPT
The Pituitary Gland
Posteriorpituitary
The hypothalamus significantly influences the pituitary gland
The hypothalamus makes and releases the hormonesof the posterior pituitary
Hypothalamic releasingand inhibiting hormones are delivered to the anterior pituitary
Pituitary (Hypophysis)
• Anterior Pituitary – “adenohypophysis”
• Posterior Pituitary – “neurohypophysis”
Oxytocin
Antidiuretic Hormone (ADH)
• 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)
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.
Acetyl CoA
Hydroxymethyl Glutaric Acid (HMG-CoA)
Mevolaonate
Mevolaonate Pyrophosphate
Isopentenyl Pyrophosphate
Geranyl Pyrophosphate
Famesyl Pyrophosphate
Squalene
CholesterolUbiquinone(CoQ10)
Dolichol
Statin = HMG-CoA reductase inhibitors
Cholesterol
Vitamin D
Cortisone
Glucocorticoids
Mineralcorticoids
Bile Salts
Steroid Hormones(testosterone, estrogen,
progesterone)
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
CRH = Corticotropin Releasing HormoneACTH = 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?
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
"Moon" face, "Buffalo" humpProtruding abdomen High Blood Pressure Weakness, Acne, Backache Excessive thirst & urination Easy Bruising
Normal Hyper-Cortisolism
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).