Anatomy lec 1

• Endocrine system

  Composed of the endocrine glands which are located throughout the body and produce different endocrine hormones and release them into the bloodstream
• Components of the endocrine system


  • Hypothalamus
  • Pineal gland
  • Pituitary gland
  • Thyroid gland
  • Parathyroid gland
  • Ovaries
  • Testes
  • Pancreas
  • Adrenal glands
• Pituitary gland


  Very important endocrine gland, vital to life, its hormones influence activities of other endocrine glands (master endocrine gland)
• Pituitary gland


  • Small (pea-sized) oval structure attached to under surface of brain by infundibulum (pituitary stalk)
  • Well protected by its location in sella turcica of sphenoid bone

  
• Lobes of pituitary gland

  • Anterior lobe (adenohypophysis)
  • Posterior lobe (neurohypophysis)

  
• Subdivisions of anterior lobe

  • Pars anterior (pars distalis)
  • Pars intermedia
  • Pars tuberalis
• Infundibulum of pituitary gland


  • Connects anterior and posterior lobes

  
• Diaphragma sellae


  Separates anterior lobe from optic chiasma
• Structures located inferiorly to pituitary gland

  • Body of sphenoid
  • Sphenoidal air sinus

  
• Structures located laterally to pituitary gland

  • Cavernous sinus and its contents (internal carotid artery, abducent nerve)

  
• Structures located posteriorly to pituitary gland

  • Dorsum sellae
  • Basilar artery
  • Pons

  
• Arteries supplying pituitary gland

  • Superior hypophyseal artery
  • Inferior hypophyseal artery
• Veins draining pituitary gland

  Drain into intercavernous sinuses
• Hypophyseal portal system


  Superior hypophyseal artery forms capillary network around hypothalamus, blood then transported to secondary capillary plexus surrounding anterior pituitary, allowing hypothalamus to communicate with anterior pituitary via neurotransmitters
• Functions of pituitary gland

  Influences activities of many other endocrine glands, controlled by hypothalamus
• The pituitary gland is located in the sella turcica of the sphenoid bone