Development of the digestive system

Question 1

What occurs during week one of development?

Answer 1

Fertilisation to implantation

Question 2

What forms in week 2 of development?

Answer 2

Bilaminar Germ Disk

Question 3

What occurs in week 3 of development?

Answer 3

Trilaminar Germ Disc forms

Question 4

What occurs in weeks 3-8 of development?

Answer 4

Organogenesis

Question 5

What is the first phase of embryonic development?

Answer 5

Growth phase - cells divide

Question 6

What is the second phase of embryonic development?

Answer 6

Morphogenesis - development of shape, size of organs

Question 7

What is the third phase of embryonic development ?

Answer 7

Differentiation - Maturation of physiological processes

Question 8

What does the ectoderm form?

Answer 8

Skin, CNS, PNS, liver, eyes, nose, ears

Question 9

What does the endoderm form?

Answer 9

Epithelial lining of resp. system, GIT, Liver,pancreas, thyroid, bladder etc

Question 10

What does the mesoderm?

Answer 10

Muscle, bones, cartilage, dermis, vascular system, urogenital system, spleen etc

Question 11

The lateral plate mesoderm gives rise to what?

Answer 11

Parietal and visceral mesoderm

Question 12

Where does the foregut arise from?

Answer 12

The cranial part of the primitive gut tube

Question 13

What divides the foregut into trachea and oesophagus?

Answer 13

Tracheo-oesophageal septum

Question 14

When does the foregut dilate to form the stomach?

Answer 14

Week 4

Question 15

How is the stomach attached to the dorsal and ventral wall?

Answer 15

Via a mesentery called the mesogastrium

Question 16

How is the duodenum formed?

Answer 16

From the caudal part of the foregut and the cranial part of the midgut

Question 17

What supplies the duodenum?

Answer 17

The coeliac trunk and the superior mesenteric artery

Question 18

When does the liver bud appear?

Answer 18

Third week

Question 19

When does the spleen form

Answer 19

END OF WEEK 4/ START OF WEEK 5

Question 20

What occurs if the tracheo-oesophageal septum deviates incorrectly?

Answer 20

Atresia and tracheo-oesophageal fistula

Question 21

What occurs if the ventral bud fails to deviate around the duodenum correctly?

Answer 21

Annular pancreas which may result in duodenal stenosis

Question 22

What does the midgut form?

Answer 22

The distal part of the duodenum, jejunum, ileium, caecum, appendix, ascending colon and proximal 2/3 of transverse colon

Question 23

What does the cephalic part of the primary intestinal loop form?

Answer 23

The distal duodenum, jejunum and the proximal ileum

Question 24

What does the caudal part of the distal ileum become?

Answer 24

Distal ileum, appendix, ascending colon and proximal 2/3 of the transverse colon

Question 25

When does midgut rotation occur?

Answer 25

Week 6

Question 26

What is omphalocele and how does it occur?

Answer 26

The herniation of abdominal viscera through an enlarged umbilical ring as a result of the failure of retraction of umblilical ring

Question 27

What happens if there are remnants of the vitelline duct?

Answer 27

Meckels diverticulum which may form fistula or cyst

Question 28

What does the hindgut form?

Answer 28

Distal 1/3 of transverse colon, descending colon, sigmoid colon, rectum and upper part of anal canal

Question 29

What does the endoderm of the hindgut form?

Answer 29

the lining of the bladder and urethra

Question 30

What supplies the hindgut?

Answer 30

The inferior mesenteric artery

Question 31

When does the liver form?

Answer 31

Week 3

Question 32

What is gastrochisis?

Answer 32

Herniation of abdo viscera. No amnion covering viscera

Question 33

What layer makes the spleen?

Answer 33

Mesoderm

Question 34

When does midgut rotation occur?

Answer 34

Week 6