01:119:116 Lecture Notes - Lecture 17: Polarity In Embryogenesis, Archenteron, Filopodia
4 Nov 2018
School
Department
Course
Professor
Document Summary
Seq, cc, hd human development: after cleavage, rate of cell division slows down (pg. 1043, morphogenesis, process by which animal body takes shape, last two stages of embryonic development: gastrulation + organogenesis. Recognition of a hollow blastula into a gastrula ( layered embryo) Diploblasts (radial symmetry) ectoderm and endoderm. Seq events ( 5 steps of fig 47. 8) Migration invagination filopodia contraction fusion: begins at vegetal pole. Group of mesenchyme cells migrate from vegetal pole into. Some mesenchyme cells will later secrete calcium carbonate blastocoel. Simple internal skeleton: cells at vegetal pole flatten vegetal pole buckle inward. Infolding of a sheet of cells into embryo: archenteron (future digestive tube) Mesenchyme cells at tip of archenteron produce filopodia (thin extensions, extend toward blastocoel wall: filopodia contract. Gastrula: 3 germ layers, digestive tract, mouth + anus, cilia: feeding + movement: gastrulation in frogs (vertebrates) Each germ layer distinct set of structures ( fig 47. 9) Gastrulation begins on dorsal side of blastula.
