12. Gut Embryology Flashcards
What are the functions of the yolk sac?
Generation of blood cells in wall
Origin of primordial germ cells
What does the vitelline duct connect?
Gut tube to yolk sac
What suspends the gut tube from the dorsal body wall?
Dorsal mesentery
What is the ventral mesentery derived from?
Septum transversum
What divides the ventral mesentery?
Liver
Divides into falciform ligament and lesser omentum
What tissue is the septum transversum made from?
Mesodermal
Where does the septum transversum extend from?
Thorax to stalk of yolk sac
What are the derivatives of the septum transversum?
Ventral mesentery
Diaphragm
Part of liver
What type of hernia occurs if there is an opening between the sternal and costal heads of the diaphragm?
Hernia of Morgagni
What type of hernia occurs if there is an absence of pleuroperitoneal membrane?
Hernia of Bochdalek
What are the results of a diaphragmatic hernia?
Abdominal organs move into pleural cavity
Impaired lung function and growth
What marks the beginning of the foregut in the embryo?
Tracheobronchial diverticulum
What is the first part of the embryological gut tube called?
Pharyngeal gut
What needs to form to separate the oesophagus from the trachea?
Tracheoesophageal ridge
What is a tracheoesophageal fistula?
Oesophagus joins up to the trachea
What is oesophageal atresia?
Gut tube isn’t joined
What nerve innervates the anterior of the stomach?
Left vagal nerve
What nerve innervates the posterior of the stomach?
Right vagal nerve
What is pyloric stenosis?
Extreme narrowing of the pylorus
Results in projectile vomiting
Describe how the duodenum becomes retroperitoneal
Originally develops on mesoduodenum
As the stomach rotates, the duodenum rotates to the right
This presses it against the posterior abdominal wall, making it a retroperitoneal structure
What happens to the gut tube during week 6?
Endodermal cells lining the tube proliferate and obliterate the lumen
Describe the development and positioning of the spleen
Forms within dorsal mesentery
Initially in isolated islands, which then join up
Moves to left as stomach rotates
Where does the liver bud grow from?
Endodermal epithelium from foregut
What 2 sources of cells are used to make up the liver?
Endothelium from bud
Hepatocytes
