BIOC19H3 Lecture 6: Notes
Document Summary
Lecture 6: differentiation and growth of tissues and organs during development, after gastrulation (and formation three germ layers), internal organs begin form. Organogenesis: period during development when internal organs are being formed, organ composed of group of tissues that work in coordinated manner to perform specific functions, most organogenesis has begun by 5th week gestation in humans. In embryo, internal organs are forming (liver, pancreas, lungs, gi tract, esophagus, stomach, intestine) Two important interacting tissues during organogenesis of internal organs- iec & mes. Basal surface of iec cell is next to basement membrane. Internal epithelial cells (iec: arranged in a layer or sheet of cells, cells exhibit polarity-apical surface and basal surface (apical surface specializations: microvilli for absorption; cilia for movement) Iec connected together by junctional complexes and cell adhesion molecules (cams: during development: iec line ducts of developing organs; give rise to differentiated cells of internal organs. In adult: internal epithelial cells line internal organs, ducts, glands, blood vessels.
