ANAT 2130 Lecture Notes - Lecture 10: Syndactyly, Intramembranous Ossification, Limb Bud
16 Oct 2016
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Document Summary
Cellular & genetic mechanisms of organ formation i. Human development begins with fertilization in the oviduct. Cleavage: first major phase of embryonic development. It is the paid succession of cell divisions. Mesoderm: the middle layer which partly fills the space between ectoderm and endoderm. Cleavage gastrulation organogenesis histogenesis (2 weeks) (1 week) (4 weeks) (7 months) Organogenesis: formation of organ rudiments from the three embryonic germ layers to establish the basic body plan (germ layers > organ rudiments) Histogenesis (tissue differentiation: differentiation of cells within the organs to form specialized tissues. Tissues are composed of cells and extracellular material that perform a specific function (organ rudiments > functional organ) Embryonic tissue layers differentiate into specific organ/tissue systems. Ectoderm forms: skin and associated glands, nervous system. Mesoderm forms: muscles, skeleton, gonads, excretory system, circulatory system. Endoderm forms: lining of digestive tract, liver, pancreas, lungs. *rudiments are small and primitive lacking functionally differentiated cells*
