Gut formation

Question 1

What structures are represented by A and B?

Answer 1

The lesser omentum and falciform ligament, respectively

Question 2

What causes this malformation?

Answer 2

Failure of the herniated gut to spontaneously reduce

Question 3

What artery does the gut twist around during development?

Answer 3

The superior mesenteric artery

Question 4

What type of embryonic tissue is the connective tissues of the lungs derived from?

Answer 4

The visceral mesoderm

Question 5

What makes the connective tissue for the liver?

Answer 5

The septum transversum

Question 6

What is the portal triad?

Answer 6

The protal vein, commong bile duct and proper hepatic arter

Question 7

What stimulates the growth of the liver and where do cells of the septum transversum arise from?

Answer 7

Molecular signals from the heart (FGF and something else)

Cardiac mesoderm constitutes the septum transversum

Question 8

What structure is embedded in the falciform ligament?

Answer 8

The umbilical vein

Forms the ligamentem teres when it closes

Question 9

Where does the ileum and jejunum reside during the 5th and 6th week?

Answer 9

The umbilicus (outside of the fetus) in the amnion

Around the 10th week, the midgut recedes back into the abdominal cavity

Question 9

What forms the greater omentum?

Answer 9

The dorsal mesentery of the stomach (hangs down from the greater curvature of the stomach)

Question 10

Hirschsprung’s disease

Answer 10

mpaired migration of neural crest cells is the underlying cause of Hirschsprung disease. Parasympathetic neural crest cells migrate in a rostral to caudal direction, from the foregut to the midgut to the hindgut. Failure of the neural crest cells to complete this migration typically results in an aganglionic distal sigmoid and rectum (i.e., without the myenteric and submucosal plexus). As a result, there is hypertonicity in the walls of the rectum and sigmoid, and the internal anal sphincter fails to relax in response to rectal distention. The net effect is intestinal obstruction and dilation of the colon (megacolon). The diagnosis is confirmed via rectal biopsy, which would show aganglionosis, increased acetylcholinesterase activity, and/or hyperplasia of parasympathetic fibers.

Amboss

Question 11

Müllerian agenesis

Answer 11

A rare, congenital defect in which the Müllerian ducts fail to fuse, which results in an atretic uterus, cervix, and upper-third of the vagina. Patients usually present during puberty with primary amenorrhea but have normal secondary sexual characteristics.