Lecture 20, Ch. 47

Lecture 20, Ch. 47 - Gastrulation Gastrula ~ 2 layered,...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture #20 Date ________ Chapter 47 ~ Animal Development
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Embryonic development/fertilization Preformation ~ until 18th century; miniature infant in sperm or egg At fertilization/conception : Acrosomal reaction ~ hydrolytic enzyme action on egg jelly coat…. Fast block to polyspermy ~ membrane depolarization prevents multiple fertilizations…. Cortical reaction ~ release of calcium causes hardening of egg outer layer and creates a. .. Slow block to polyspermy and. .. Egg activation ~ increases metabolic activity; protein synthesis
Background image of page 2
Blastomeres~ resultant cells of cleavage/mitosis Yolk ~ nutrients stored in the egg Vegetal pole ~ side of egg with high yolk concentration Animal pole ~ side of egg with low yolk concentration Morula~ solid ball of cells Blastocoel ~fluid-filled cavity in morula Blastula ~hollow ball stage of development
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Cleavage QuickTimet and a Cinepak decompressor are needed to see this picture.
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Gastrulation Gastrula ~ 2 layered, cup-shaped embryonic stage 3 Embryonic germ layers: Ectoderm~ outer layer; epidermis; nervous system , etc. Endoderm ~ inner layer; digestive tract and associated organs; respiratory, etc. Mesoderm ~skeletal; muscular; excretory, etc. Invagination ~ gastrula buckling process to create the. .. Archenteron ~ primitive gut Blastopore ~ open end of archenteron Organogenesis: organ formation Blastodisc ~ cap of cells on top of yolk Primitive streak ~ invagination of blastodisc Neural tube ~ beginning of spinal cord Somites~ vertebrae and skeletal muscles Neural crest ~ bones and muscles of skull Amniote embryos Extraembryonic membranes : yolk sac (support; circulatory function) amnion (fluid-filled sac; protection) chorion (placenta formation) allantois (nitrogenous waste)...
View Full Document

Page1 / 7

Lecture 20, Ch. 47 - Gastrulation Gastrula ~ 2 layered,...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online