Dev.Endocrine Glands

• What is the 2 different sources for pitutary development?

  • out pocketing of stomodeum immedistely in front of buccopharyngeal memb.
  • downward extension of diencephalon (infundibulum)
• Briefly explain the divisions of pituitary gland:

  Adenohypophysis:

  • pars tuberalis
  • pars distalis
  • pars intermedia

  Neurohypophysis:

  • pars nervosa
  • infundibular stalk
  • median eminence

  pars tuberalis & distalis = anterior lobe

  pars intermedia & nervosa = posterior lobe

  infundibular stalk & median eminence = neural stalk

  pars tuberalis & neural stalk = hypophyseal stalk

  
• What is thyroid follicle?

  the solid mass of

  thyroid cells broken up into plates, cords &

  cell clusters called follicles
• What is colloid of thyroid gland?

  Homogenous eosinophilic gel-like substance

  starts to accumulate in the center of each

  follicle by 3rd month
• What is fibrous capsule?

  And connective tissue develops from the

  surrounding mesenchyme
• What is ultimobranchial bodies ?

  (5th pharyngeal pouch) & neural crest cells

  are incorporated into the thyroid gland to

  form the parafollicular cells
• 1st step in development of pituitary gland (hypophysis cerebri) ?

  Rathke’s pouch 1st evaginates from stomodeum & grow dorsally towards indunfibulum

  
• What happened after the pouch loses connection with oral cavity ?

  • anterior wall of Rathke’s pouch increased in size to form adenohypophysis

  steps seterusnya…..

  
• Briefly explain about the development of the thyroid gland

  step last:

  the gland finally develops into small,median isthmus & 2 lateral lobes

  
• Briefly explain about parathyroid gland:

  Answers:

  
• Suprarenal glands composed of?

  • adrenal cortex ( mesodermal origin)
  • adrenal medulla ( ectodermal origin)
• How adrenal cortex start to develop?

  • mesothelial cells btwn the root of mesentery & developing gonad proliferate
  • penetrate the underlying mesenchyme
  • differentiate into acidophilic cell mass known as primitive cortex