This is an extract of our Development Of The Gi System (Embryology) document, which we sell as part of our Gastrointestinal (GI) System Notes collection written by the top tier of Bristol University students.
The following is a more accessble plain text extract of the PDF sample above, taken from our Gastrointestinal (GI) System Notes. Due to the challenges of extracting text from PDFs, it will have odd formatting:
Lecture 6 Development of GI system (embryology)
Gastrulation o Week 3- Epiblast cells migrate through primitive streak to form Trilaminar disc
? Displace hypoblasts= ENDODERM (CNS/PNS and epithelium of skin)
? Lie in middle= MESODERM (Body connective tissues, GI connective tissue)
? Remain in epiblast= ECTODERM (GI tract organs & epithelium of GI) Development of the GI system o Primitive gut tube
? Stomadeum to proptadeum
? Buds coming off= organs o Divisions of gut tube
? Pharyngeal gut (part of foregut)
? Foregut (COELIAC AXIS)
? Midgut (SMA)
? Hindgut (IMA) o Differentiation of gut
? Dependent on interaction between endoderm "SHH genes" and mesoderm "HOX genes"
? All different genes go to different places o Autonomic innervation
* Coeliac ganglion- Foregut structures
* SMA- Midgut structures
* IMA- Hindgut structures
* Vagus nerve- Foregut & midgut structures
* Pelvic splanchnic nerve- Hindgut structures o Mesenteries
* Structures support gut tube to body wall
* Derived from intraembryonic coelom (mesoderm)
* Includes o Megogastrium (greater omentum); mesoduodenum; mesentery proper; mesocolon
* Only related to foregut
* Derived from septum transversum o Falciform ligament- extending liver to ventral wall
? Embryo: Unbilical vein
? After birth: round ligament o Lesser omentum- extending stomach to liver
? Portal triad: bile duct, hepatic artery, portal vein
? Forms entrance to lesser sac: EPICLOIC FORAMEN OF WINSLOW o From which germ layer are the following parts of developing gut tube derived?
? GI organs & GI mucosa= ENDODERM
? Peritoneum, GI smooth muscle & dorsal mesentery= MESODERM
Buy the full version of these notes or essay plans and more in our Gastrointestinal (GI) System Notes.