Lecture 6: Development of the gut

Question 1

What is the trimlaminar disc?

Answer 1

Ectoderm, mesoderm and endoderm

• mesoderm is split into 3 sections: para-axial, intermediate, lateral plate mesoderm (divides into 2 areas)
• notochord is between the mesoderm

Question 2

What does the para-axial mesoderm develop into?

Answer 2

Somites: skeletal muscle, vertebra, cartilage

Question 3

What does the intermediate mesoderm develop into?

Answer 3

Kidneys, gonads

Question 4

What does the lateral plate mesoderm develop into?

Answer 4

2 divisions

• splanchnic (viscera)
• somatic (body walls)

Question 5

What does the ectoderm develop into?

Answer 5

Skin, hair, nail, nervous tissue

Question 6

What does the endoderm develop into?

Answer 6

Epithelial lining of gut

Question 7

Where does the peritoneum originate from?

Answer 7

Lateral plate mesoderm
Somatic portion: parietal peritoneum
Splanchnic portion: visceral peritoneum
Space b/w these is called the peritoneal cavity

Question 8

When does craniocaudal folding occur?

Answer 8

4th week of development

Question 9

What structure goes on to form the umbilical cord?

Answer 9

Yolk sac

Question 10

What is the vitelline duct?

Answer 10

Connection between the gut and the yolk sac/umbilical cord

-it is obliterated at birth

Question 11

What does the forgut/midgut/hindgut form?

Answer 11

Foregut: oesophagus to duodenum
Midgut: duodenum to 2/3 transverse colon
Hindgut: rest of gut to anus