embryology

• What are the three Primary Embryonic Germ Layers?

  endoderm

  mesoderm

  ectoderm
• What embryonic developmental process leads to the formation of the three primary germ layers?

  gastrulation
• whats gastrulation

  Gastrulation occurs during week 3 of human development. The process of gastrulation generates the three primary germ layers ectoderm, endoderm, and mesoderm. Gastrulation primes the system for organogenesis and is one of the most critical steps of development.
• What are the structures derived from the primary embryonic endodermal germ layer?

  epithelial lining of GI tract

  the epithelial lining of the respiratory tract, the urinary

  bladder and urethra, and the tympanic cavity and auditory

  tube.
• Pancreatic islets of Langerhans cells –

  four types:

  Alpha cells, secrete glucagon.

  Beta cells, secrete insulin.

  Delta cells, secrete somatostatin.

  Pancreatic polypeptide or F- cells, secrete pancreatic

  polypeptides.
• Pancreatic Cancer

  There are two types of pancreatic cancers:

  Exocrine pancreatic cancer (95% of the cancers), called

  adenocarcinoma, originates mainly in the head of the pancreas.

  Endocrine pancreatic cancer, called pancreatic neuroendocrine

  tumours.
• Cancer of the head of the pancreas often compresses and obstructs the

  bile duct, enlargement of the gallbladder and/or the hepatopancreatic

  ampulla because of its close relationships.

  This often leads to obstructive jaundice.