Development of the GIT

Question 1

How prevalent is Meckel’s diverticulum?

Answer 1

2% of the population

Question 2

Where is Meckel’s diverticulum located?

Answer 2

2 feet from the ileocaecal valve

Question 3

How long is a Meckel’s diverticulum?

Answer 3

2 inches (5cm) long

Question 4

What is a Meckel’s diverticulum?

Answer 4

A remnant of the vitello-intestinal duct that extends from the mid gut to the yolk sac

Question 5

When is the vitello-intestinal duct expected to close?

Answer 5

9th week of gestation

Question 6

When do people usually present with Meckel’s diverticulum?

Answer 6

2 years of age

Question 7

What kind of ectopic tissue might be found in a Meckels diverticulum?

Answer 7

Pancreatic and gastric mucosa

Question 8

What is the innervation for the foregut?

Answer 8

T5-T9

Question 9

What is the blood supply to foregut?

Answer 9

Coeliac artery

Question 10

What forms the serosal layer of the GIT?

Answer 10

Splanchnic lateral plate of the mesoderm

Question 11

Which part of the duodenum is contained within the foregut?

Answer 11

The first 2 parts

Question 12

Which part of the duodenum within the midgut?

Answer 12

The second 2 parts

Question 13

Which structures compose the foregut?

Answer 13

Oesophagus and 1st 2 parts of duodenum
Liver
Pancreas
Gallbladder
Spleen

Question 14

What is the innervation of the midgut?

Answer 14

T10-T11

Question 15

What is the blood supply to the midgut?

Answer 15

Superior mesenteric artery

Question 16

What is the midgut composed of?

Answer 16

Last 2 sections of the duodenum, jejunum, caecum, ascending colon, proximal 2/3 of transverse colon

Question 17

How does the stomach rotate during embryology?

Answer 17

It rotates 90 degrees clockwise

Question 18

When does the midgut retract into the abdominal cavity?

Answer 18

During the 10th week of development

Question 19

How much does the intestines rotate during embryonic development?

Answer 19

240 degrees anti-clockwise

Question 20

When does the midgut herniate out of the abdominal cavity?

Answer 20

During 6th week of development

Question 21

Define an omphalocoele

Answer 21

Indirect herniation of the intestines via the umbilicus, the intestines are surrounded by a layer of amnion and this condition is often associated with chromosomal abnormalities

Question 22

Define gastroschisis

Answer 22

Direct herniation of the intestines through the abdominal wall. The intestines are not covered in amnion and therefore can be damaged by amniotic fluid and the condition is not associated with chromosomal abnormalities

Question 23

Which type of gut herniation is associated with chromosomal abnormalities?

Answer 23

Omphalocoele

Question 24

Which type of gut herniation results in intestines being damaged by the amniotic fluid?

Answer 24

Gastroschisis

Question 25

What does the hindgut consist of?

Answer 25

Distal 1/3 of the transverse colon, descending colon, sigmoid colon, rectum, and 1st half of the anal canal

Question 26

What is the blood supply to the hindgut?

Answer 26

Inferior mesenteric artery

Question 27

What is innervation of the hindgut?

Answer 27

T12-L1

Question 28

Which embryological structure gives rise to the myenteric plexus?

Answer 28

Ectodermal neural crest cells

Question 29

What is the function of Ladds Bands?

Answer 29

Attach caecum to RLQ retroperitoneum

Question 30

How might Ladd’s Bands be affected in intestinal malrotation?

Answer 30

Malrotation can lead to Ladds bands attaching the caecum the RUQ leading to intestinal obstruction

Question 31

When does meconium first appear in the terminal ileum?

Answer 31

10-16 weeks

Question 32

When does the thyroid gland start functioning?

Answer 32

Approximately 12th week of gestation