Drive - embryology

Question 1

What layer of the embryo is mainly responsible for the development of the GI tract?

Answer 1

Endoderm

Question 2

What does endoderm give rise to? (associated with the GI tract) =3

Answer 2

Epithelial lining of the digestive tract
Hepatocytes of the liver
Endocrine and exocrine cells of the pancreas

Question 3

What does the visceral mesoderm give rise to? (associated with the GI tract) = 2

Answer 3

Muscle, connective tissue and peritoneal components of the wall of the gut
Connective tissue for the glands

Question 4

When does the mouth form?

Answer 4

At 4 weeks

Question 5

When does the anus form?

Answer 5

At 7 weeks

Question 6

How many pharyngeal arches are there and what are these called?

Answer 6

5 arches: 1, 2, 3, 4, 6

Question 7

What provides innervation to the 1st pharyngeal arch?

Answer 7

Mandibular branch of the trigeminal nerve.

Question 8

What provides innervation to the 2nd pharyngeal arch?

Answer 8

Facial nerve

Question 9

What provides innervation to the 3rd pharyngeal arch?

Answer 9

Glossopharyngeal nerve

Question 10

What provides innervation to the 4th pharyngeal arch?

Answer 10

Superior laryngeal nerve branch of the vagus nerve

Question 11

What provides innervation to the 6th pharyngeal arch?

Answer 11

Recurrent laryngeal nerve branch of the vagus nerve

Question 12

What is a mesentery?

Answer 12

Double layers of peritoneum that surrounding an organ and connect it to the body wall

Question 13

What is a ligament?

Answer 13

Double layers of peritoneum which pass from one organ to another (or from one organ to the body wall)

Question 14

What do mesenteries and ligaments provide?

Answer 14

Provide pathways from blood vessels, lymphatics and nerves to go to and come from the abdominal viscera.

Question 15

What part of the GI tract is ventral mesentery and dorsal mesentery located?

Answer 15

Ventral mesentery = Foregut only

Dorsal mesentery = Foregut, midgut and hindgut

Question 16

What does the free lower margin of the ventral mesentery contain? (3)

Answer 16

Hepatic artery, portal vein and bile duct

Question 17

What causes the formation of the lesser omentum and the falciform ligament?

Answer 17

The development of the liver in the ventral mesentery.

Question 18

What causes the signature curvatures of the stomach?

Answer 18

The dorsal wall (the part attached to the dorsal mesentery) grows faster than the ventral wall (the part attached to the ventral mesentery).

Question 19

During what week is the lesser sack formed and why?

Answer 19

7th week - as the stomach rotates 90o clockwise.

Question 20

Through what do the greater and lesser sacs communicate?

Answer 20

epiploic foramen

Question 21

From what do hepatocytes originate from?

Answer 21

Endoderm

Question 22

From what do the exocrine and endocrine cells of the pancreas originate from?

Answer 22

Endoderm