pituitary and pineal

• the pituitary gland is located in a bony cavity called

  sella tursica
• adenohypophysis consists of

  pars distalis and pars intermedia
• pars distalis is the anterior pituitory
• neurohypophysis (pars nervosa) is also called posterior pituitary
• over-secretion of GH stimulates abnormal growth of the body leading to gigantism
• under-secretion of GH results in stunted growth and pituitary dwarfism
• excess secretion of GH in adults leads to severe disfigurement of face which results in acromegaly
• prolactin regulates growth of mammary glands and formation of milk in them
• TSH stimulates synthesis and secretion of thyroid hormones from the thyroid gland
• ACTH stimulates the adrenal cortex to produce glucocorticoids
• LH and FSH are called

  gonadotrophins
• in males, LH stimulates synthesis and secretion of androgens from testis
• LH and interstitial cells both produce

  androgens
• in males, FSH and androgens regulate

  spermatogenesis
• in females, LH induces ovulation of fully mature follicles and maintains the corpus luteum after ovulation
• in females, FSH stimulates the growth of the follicles
• MSH is secreted by

  pars intermedia
• MSH acts on melanocytes and regulates pigmentation of skin
• posterior pituitary stores and releases two hormones called

  oxytocin and vasopressin
• posterior pituitary hormones are actually synthesized by the

  hypothalamus
• oxytocin acts on smooth muscles and stimulate their contraction
• oxytocin stimulates vigorous contraction of uterus at the time of childbirth AND ejection of milk from the mammary glands
• vasopressin stimulates resorption of water and electrolytes from the the distal tubules of kidney and thereby reduces loss of water through urine
• vasopressin prevents diuresis and thus also called ADH
• impairment affecting ADH secretion results diminished ability of kidney to conserve water and results in water loss and dehydration. this condition is known as

  diabetes insipidus
• pineal gland is located on the

  dorsal side of forebrain
• melatonin maintains normal rhythm of sleep-wake cycle, body temperature, metabolism, pigmentation and menstrual cycle