Embryology of foregut, midgut, and hindgut Flashcards
Vacuoles develop in this mesoderm subtype leading to the formation of intraembryonic coelom
Lateral plate mesoderm
Intraembryonic coelom expansion leads to formation of these 2 layers of the lateral plate mesoderm
Parietal and visceral layers
This mesoderm gives rise to abdominal wall and peritoneal cavity
Parietal plate mesoderm
This mesoderm gives rise to connective tissue of gut and smooth muscle of gut tube
Visceral plate mesoderm
As a result of craniocaudal and lateral folding, a portion of this is incorporated into embryo to form the primitive gut tube
Yolk sac
Congenital abdominal wall defect towards the right side of the umbilicus and protruded bowel not covered by membrane
Failure of migration and fusion of the lateral folds of the embryonic disc on the 3rd-4th week of gestation
Gastroschisis
Gastroschisis is due to failure of migration and fusion of these
Lateral folds of the embryonic disc
Normally fuse on the 3rd-4th week of gestation
This is where visceral and parietal layers of peritoneum are continuous with each other
Dorsal mesentery
The primitive abdominal gut is initially a straight tube suspended in the peritoneal cavity by this
Dorsal mesentery
Dorsal mesentery is where these layers of peritoneum are continuous with each other
Visceral and parietal layers
This part of the mesentery gives rise to a multitude of structures as it is invaded by the liver
Ventral mesentery
This becomes obliterated after birth and is replaced by a fibrous cord known as the ligamentum teres
Umbilical vein
The umbilical vein becomes obliterated after birth and is replaced by a fibrous cord known as this
Ligamentum teres
Development of this due to stomach rotation gives rise to the ligaments of the spleen
Dorsal mesentery
Development of the dorsal mesentery due to stomach rotation gives rise to the ligaments of this organ
spleen
By the 4th week, this structure, which is now the peritoneal cavity, becomes partitioned into pericardial, pleural, peritoneal
Intraembryonic coelom
This is a block of mesoderm that lies between the pericardial and peritoneal partitions and forms connective tissue in the liver and the central tendon of the diaphragm
Septum transversum
The primitive gut tube is initially closed at its cranial end by this, and at its caudal end the cloacal membrane
Oropharyngeal membrane
The primitive gut tube is initially closed at its cranial end by the oropharyngeal membrane, and at its caudal end by this
Cloacal membrane
The foregut receives supply from this artery
Celiac artery
The midgut receives supply from this artery
Superior mesenteric artery
The hindgut receives supply from this artery
Inferior mesenteric artery
This part of the primordial gut receives arterial supply from the celiac artery
Foregut
This part of the primordial gut receives arterial supply from the superior mesenteric artery
Midgut
This part of the primordial gut receives arterial supply from the inferior mesenteric artery
Hindgut
The tracheoesophageal septum gradually partitions this diverticulum from the dorsal part of the foregut
Respiratory diverticulum
This results from the failure of the primitive foregut to recanalize
Esophageal atresia
Esophageal atresia results from the failure of this to recanalize
Primitive foregut
This occurs due to failure of the lung bud to separate completely from the foregut
Tracheoesophageal fistula
Tracheoesophageal fistula occurs due to failure of this to separate completely from the foregut
Lung bud
Tracheoesophageal fistula occurs due to failure of lung bud to separate completely from this
Foregut
In this defect, liquid can pass into the baby’s lungs, which can result in pneumonia
Tracheoesophageal fistula
Does the primitive stomach rotate 90 degress clockwise or counterclockwise during development?
Clockwise
This condition forms a small palpable mass (“olive”), causing a narrow pyloric lumen that obstructs food passage
Hypertrophic pyloric stenosis
This condition is more prevalent in males and associated clinically with projectile vomiting after feeding and a small, palpable mass at the right costal margin
Hypertrophic pyloric stenosis
Does the ventral or dorsal pancreatic bud give rise to the main pancreatic duct (Wirsung)?
Ventral
Is the entrance to the common bile duct originally ventral or dorsal?
Ventral
becomes a dorsal structure with the rotation
This portion of the duodenum is intraperitoneal, while the rest of the duodenum is retroperitoneum
Superior portion
(due to the hepatoduodenal ligament)
The hepatocytes and simple columnar or cuboidal epithelium lining the biliary tree of the definitive liver are derived from endoderm or mesoderm?
Endoderm
Kupffer’s cells, hematopoietic cells, endothelium of the sinusoids, and fibroblasts (connective tissue) of the definitive liver are derived from endoderm or mesoderm?
Mesoderm
Does the midgut loop rotate 90 degrees clockwise or counterclockwise during development?
counterclockwise
(contrast to stomach, which rotates clockwise)
Does the rotation of the midgut loop bring the cranial limb (small intestine) to the right or left?
Right
Does the rotation of the midgut loop bring the caudal limb (large intestine) to the right or left?
Left
Failure of the most proximal portion of the omphalomesenteric duct to obliterate results in this defect
Meckel’s diverticulum
Failure of this duct to obliterate results in a Meckel’s diverticulum
Omphalomesenteric duct
This part of the cloaca gives rise to the urinary bladder and urethra
Urogenital sinus (ventral)
This part of the cloaca gives rise to the rectum and proximal 2/3 of anal canal
Anorectal canal (dorsal)
Is the upper part of the anal canal derived from endoderm or ectoderm?
Endoderm
(of the hindgut)
Is the lower part of the anal canal derived from endoderm or ectoderm?
Ectoderm
(around the proctodeum or anal pit)
The inferior portion of the hindgut is delineated by the presence of this and has a different embryological origin then the rest of the hindgut
Pectinate line
(This change from endodermal origin to ectoderm leads to difference in innervation, blood supply and lymphatic drainage)
