Session 2

Question 1

Development of the GI tract begins when folding of the embryo creates a

Answer 1

Primitive gut tube, lined with endoderm, divisible into 3 regions

Question 2

3 regions of the primitive gut tube

Answer 2

Foregut, mid gut, hindgut

Question 3

Each embryonic segment receives a blood supply from a distinct branch of the

Answer 3

Abdominal aorta

Question 4

Structures developing close to the foregut/midgut junction will have a

Answer 4

Mixed blood supply

Question 5

Development of the primitive gut tube begins in

Answer 5

Week 3

Question 6

Internal lining derived from and becomes

Answer 6

Endoderm (future epithelia)

Question 7

External lining derived from and becomes

Answer 7

Splanchnic mesoderm (future musculature and peritoneum)

Question 8

The mesoderm surrounding the guts splits into which layers

Answer 8

Somatic- becomes abdominal wall
Splanchnic- becomes smooth muscles of the gut wall

Question 9

The space created by the split of the mesoderm surrounding the gut is called

Answer 9

Coelomic cavity- begins as one large cavity (forerunner of pleural cavity and peritoneal cavity)

Question 10

What are mesenteries

Answer 10

Double folds of peritoneum that suspend the gut tube from the abdominal wall

Question 11

What are omenta

Answer 11

Specialised regions of peritoneum

Question 12

Greater and lesser omentum are derived from

Answer 12

Dorsal mesentary and ventral mesentary

Question 13

How is the developing gut attached to the roof of the abdominal cavity and floor

Answer 13

Fold of mesoderm known as the dorsal mesentary

Floor by ventral mesentary

Question 14

What do the dorsal and ventral mesenteries become in adults

Answer 14

Various peritoneal folds and reflections that suspend the gut and give passage to vessels and nerves in the adult

Question 15

Which parts of the GI tract remain suspended from posterior abdominal wall by mesentary and remain mobile

Answer 15

Jejenum and ileum

Question 16

Where does the foregut and hindgut initially end

Answer 16

Oropharyngeal membrane and cloacal membrane

Question 17

What happens when the Oropharyngeal and cloacal membranes break down

Answer 17

Gut becomes open to the exterior at the future mouth and anus

Question 18

The greater and lesser sacs of the peritoneal cavity are formed by

Answer 18

Rotation of the stomach

Question 19

What are structures not suspended in the peritoneal cavity termed

Answer 19

Retroperitoneal

Question 20

What happens in the 4th week

Answer 20

A respiratory diverticulum develops in the ventral wall of foregut

Oesophagus sits behind this in a dorsal position

Question 21

Why does the stomach have its characteristic greater curve

Answer 21

Dorsal border develops faster

Question 22

The liver develops within what along with what

Answer 22

Ventral mesentary, along with biliary system and uncinated process of Pancreas

Question 23

What does the pancreas develop from

Answer 23

2 portions (dorsal portion forming most of gland, ventral portion forming most of duct system)

Question 24

The liver grows into the ventral mesentary dividing it into two parts called

Answer 24

Falciform ligament and lesser omentum

Question 25

When is the duodenum’s lumen obliterated

Answer 25

5th and 6th weeks of its development, only recanalised by end of embryonic period

Question 26

Secondarily retroperitoneal structures initially had a mesentary that was lost to what

Answer 26

Fusion with the posterior abdominal wall

Question 27

What is a hernia

Answer 27

A protrusion of part of the abdominal contents beyond the normal confines of the abdominal wall

Question 28

What are the three parts of a hernia

Answer 28

Sac, contents and coverings

Question 29

What is the inguinal canal

Answer 29

Oblique passage through the lower abdominal wall, layers of anterolateral abdominal muscles

Question 30

Anterior wall of inguinal canal is mainly composed of

Answer 30

Aponeurosis of external oblique

Question 31

The floor of the inguinal canal is composed of the

Answer 31

Inguinal ligament and the lacunae ligament medially

Question 32

What is the roof of the inguinal canal made of

Answer 32

Arching fibres of internal oblique and transverse abdominus

Question 33

What is the posterior wall of the inguinal canal made of

Answer 33

Transversal is fascia and conjoint tendon medially

Question 34

What are the most common abdominal wall hernias

Answer 34

Inguinal hernias

Question 35

Inguinal hernias types

Answer 35

Indirect and direct (indirect are more common and males are more commonly affected)

Question 36

Indirect hernias exit the abdomen through the

Answer 36

Deep inguinal ring and pas into the inguinal canal to a variable distance Some pass through to the scrotum

Question 37

Direct inguinal hernias pass directly through the

Answer 37

Abdominal wall, in an area of potential weakness called Hesselbach’s triangle

Question 38

How do anatomically direct and indirect inguinal hernias differ

Answer 38

By their relationship to the inferior epigastric vessels and whether they enter inguinal canal or not Indirect pass laterally whereas direct pass medially

Question 39

Femoral hernias pass through the

Answer 39

Femoral ring and into the femoral canal More common in females and are at risk of incarceration

Question 40

When does bucopharyngeal membrane ruptured

Answer 40

4th week

Question 41

When does cloacal membrane rupture

Answer 41

7th week

Question 42

What is foregut

Answer 42

Oesophageal to mid point of 2nd part of duodenum

Question 43

What is midgut

Answer 43

Duodenum to 2/3 transverse colon

Question 44

What is hindgut

Answer 44

Distal 1/3 of transverse colon to cloaca

Question 45

What is Vitelline duct

Answer 45

Connection between yolk sac and mid gut

Question 46

What should happen to Vitelline duct

Answer 46

Should completely obliterate before time of birth - if not then meckel’s diverticulum : out pouching of SI, Or connection between midgut and umbilicus- faecal material comes out of umbilicus

Question 47

What occurs simultaneous to cranio caudal folding

Answer 47

Lateral folding - helps form anterior/central body wall

Question 48

What supplies foregut

Answer 48

Coeliac artery

Question 49

What supplies mid gut

Answer 49

Superior mesenteric artery

Question 50

What supplies hind gut

Answer 50

Inferior mesenteric artery

Question 51

What happens to the endoderm at 5th and 9th week

Answer 51

Proliferates then occludes lumen- then recanalised at 9th

Question 52

What develops to cleave off trachea and oesophagus

Answer 52

Tracheoesophageal septum

Question 53

Features of pain in parietal peritoneum

Answer 53

Somatic mesoderm can localise pain

Question 54

Features of pain in visceral peritoneum

Answer 54

Splanchnic mesoderm- vague pain

Question 55

Peritoneal ligaments anterior to posterior

Answer 55

Falciform ligament (liver) Lesser omentum (stomach) Gastrosplenic ligament (spleen) Spleno-regal ligament (left kidney)

Question 56

Formation of peritoneal sacs

Answer 56

Greater and lesser cavity

Question 57

Feature of lesser omentum

Answer 57

Totalen of winslow or epiploic Foramen

Question 58

What is a ganglion

Answer 58

A group of cell bodies outside of the central venous system

Question 59

Where in the wall of the gut lies the myenteric nerve plexus

Answer 59

Between inner circular and outer longitudinal muscle layer

Question 60

Above the arcuate line, the aponeurosis of which muscles envelop anterior surface of rectus abdominus muscles

Answer 60

External oblique and half of internal oblique

Question 61

Below the arcuate line, the aponeurosis of which muscles envelop anterior surface of rectus abdominus muscles

Answer 61

Half of internal oblique, transversalis fascia