embryology GI shahana Flashcards
What is Gastrulation and when does it occur?
Week 3 Embryonic Stage
Blastula to Gastrula
Single layer to multi layer
cell differentiation occurs
Which structures does the foregut form?
Foregut gives rise to the esophagus, stomach, liver, gallbladder, bile ducts, pancreas and proximal duodenum.
Which structures does the midgut form?
The midgut develops into the distal duodenum, jejunum, ileum, cecum, appendix, ascending colon, and proximal 2/3 of transverse colon.
Which structures does the hindgut form?
The hindgut becomes the distal 1/3 of the transverse colon, descending colon, sigmoid colon and the upper anal canal.
Some genes are responsible for establishing the left sidedness of the organ or body part (e.g. abnormal expression of left sidedness genes may results in dextrocardia). Which gene is a transcription factor for establishing left sidedness?
PTX2
Whats the time frame for fertilisation and implantation?
Fertilisation- 12-24hrs
Implantation- 5.5-6days
In which week does the bilaminar germ disc form?
2
In which week does the trilaminar germ disc form?
3
Which weeks of development are most susceptible to damage from teratogens?
4-8
name the 3 phases of embryonic development
1- Proliferation
2- Morphogenesis
3- Differentiation
What happens in the first stage of development?
cell division and elaboration of products
What happens in the second stage of development?
development of shape, size of a particular organ or part of the body
What happens in the third stage of development?
maturation of physiological processes
what does the bilaminar disc turn into during gastrulation?
trilaminar disc
name 6 structures that form from the ectoderm
Skin CNS PNS ear nose liver
