endocrinology

• what is endocrinology?

  • branch of physiology & medicine concerend with endrocrine glands & hormones
• what are hormones?

  • special chemical messengers in body created by endocrine glands
  • control most major bodily functions
• 7 endocrine glands?

  1. pituitary
  2. thyroid
  3. parathyroid
  4. adrenal
  5. ovaries
  6. testes
  7. pancreas
• what is pituitary gland?

  • controls most glands in body
  • divided into 2 lobes:
  • anterior - produces various hormones
  • posterior - stores various hormones in hypothalamus
• anterior lobe?

  • growth hormone - skeletal growth
  • acth - stimulates adrenals & steroids
  • fsh & lh - stimulate testes/ovaries - sex hormones
  • tsh - stimulate thyroid
  • prolactin - stimulates breast milk production
• posterior lobe?

  • adh - stimulates water reabsorption by kidneys
  • oxytocin - helps uterine contractions during labour
• how is pituitary gland controlled?

  • crh - stimulates acth stimulation
  • ghrh - stimulates gh secretion
  • trh - stimulates tsh secretion
  • gnrh - stimulates fsh & lh secretion
  • prolactin releasing hormone does not exist - under inhibitory effects of hypothalamus
• thyroid gland?

  • thyroid composed of: midline isthmus, right & left lobe
  • arranged in follicles & produce thyroid hormones
  • contains C cells - produce calcitonin - calcium metabolism
  • thyroid hormones interact with their receptors in various organs - regulates gene expression
• control of thyroid hormone secretion?

  hypothalamus - trh - tsh
• adrenal glands?

  • composed of: adrenal cortex & produces cortisol, rogens, aldesterone - not controlled by pituitary - BP
  • adrenal medulla & produces adrenaline, noradrenaline, dopamine - not controlled by pituitary - BP
• ovaries?

  • situated in pelvis on either side of uterus
  • contains follicles (containing oocytes) at different stage of maturation during reproductive life
• testes?

  • found in scrotum
  • composed of interstitial/leydig cells - produce testosterone
  • semi ferous tubules - made of germ cells - produce sperm
  • sertoli cells - helps sperm production & produce inhibin
• growth hormone oversecretion?

  • excressive growth spurt & increased size of feet & hands - gigantism
  • acromegalic face
  • hearing loss
  • wide & large hands & feet
  • increased sweating
  • cardiomyopathy
• excess cortisol - cushing syndrome?

  • growth arrest in children
  • looks like:
  • round face
  • acne
  • truncal obesity/thin
  • easy bruising
  • symptoms:
  • hypertension
  • diabetes
  • poor wound healing
  • high risk of infections
• thyroid hormone excess?

  • due to primary hyperthyroidism - very common
  • symptoms:
  • hand tremor
  • increased sweating
  • fast pulse
  • weight loss
  • menstrual problems
• growth hormone deficiency?

  • failure of growth in children
• cortisol deficiency?

  • due to adrenal failure/pituitary failure
  • treated by hydrocortisone tablets
  • symptoms:
  • severe tiredness
  • failure to grow in children
  • dizziness due to low BP
  • vomiting
• hypothyroidism?

  • very common in older ladies
  • primary - thyroid failure