Session 2

Question 1

When does development of the primitive gut tube begin

Answer 1

Week 3

Question 2

What 2 layers does the mesoderm split into in the gut

Answer 2

Somatic- develops into the abdominal wall

Splanchnic- smooth muscles of the gut

Question 3

What is the space between the splanchnic and somatic mesoderm

Answer 3

Coelomic cavity- pre cursor to pleural cavity and peritoneal cavity

Question 4

What are omenta

Answer 4

Specialised regions of peritoneum

-the greater omentum is derived from the dorsal mesentary

Question 5

How do the greater and lesser sacs form

Answer 5

Rotation of the stomach

Question 6

What gives passage to folds and reflections that suspends the gut

Answer 6

The dorsal and ventral mesenteries

Question 7

How is the oropharyngeal membrane and hind gut at the cloacal membrane

Answer 7

Closed but when the membranes break down, the gut becomes open to the exterior at the future mouth and anus

Question 8

What are retroperitoneal structures

Answer 8

Structures that are not suspended within the peritoneal cavity

Question 9

Why does the stomach have its distinct curvature

Answer 9

When the dorsal border develops it develops faster

Question 10

How is the liver divided into 2

Answer 10

It grown into the ventral mesentery dividing it into 2 parts- the falciform ligament and lesser omentum

Question 11

What is a hernia

Answer 11

A protusion of part o the abdominal contents being the normal confines of the abdominal wall

Question 12

What does a hernia consist of

Answer 12

Sac, contents and coverings

Question 13

What is the inguinal canal

Answer 13

An oblique passage through the Lowe abdominal wall predominantly composed of layers from the antrolateral abdominal muscles

Question 14

What is the anterior wall mainly composed of

Answer 14

Aponeurosis of external oblique

Question 15

what forms the floor of the inguinal canal

Answer 15

Inguinal ligament and lacunar ligament medially

Question 16

Roof if inguinal canal

Answer 16

Arching fibres of internal oblique and transersus abdominus

Question 17

Posterior wall of inguinal canal

Answer 17

Composed of transversalis fascia and conjoint tendon medially

Question 18

What are the mos common abdominal wall hernias

Answer 18

Indirect Inguinal hernias and leave the abdominal cavity in the inguinal region

Question 19

Are inguinal hernias more common in males or females

Answer 19

Males

Question 20

Where do indirect hernias exit deep inguinal ring and pass into

Answer 20

the inguinal canal to variable distance some Pass through the scrotum

Question 21

Where do direct inguinal hernias pass

Answer 21

Directly through the abdominal wall in a area of potential weakness called the Hesselbach’s triangle

Question 22

How do indirect and direct hernias relate to the inferior epigastric muscles

Answer 22

Indirect pass laterally to them direct pass medially

Question 23

Are femoral hernias more common in women or men

Answer 23

Women

Question 24

Where do femoral hernias passs

Answer 24

Femoral Canal

Question 25

What happens if processus vaginalis doesnt close

Answer 25

Risk of hernias in the inguinal canal

Question 25

What happens if processus vaginalis doesnt close

Answer 25

Risk of hernias in the inguinal canal

Question 26

What is a omphalocele

Answer 26

Failure of the midgut to return to the abdomen during development

Question 27

Gastroschisis

Answer 27

Defect in ventral abdominal wall Abdominal viscera not covered in peritoneum- exposed to amniotic fluid

Question 28

Umbilical hernia

Answer 28

Hernia bulge at the site of umblicus

Question 29

Para-umbilical hernia

Answer 29

Goes through linea alba in region of umbilicus

Question 30

symptoms of hernia

Answer 30

Vomiting Sepsis Pain

Question 31

inCarcerated hernia

Answer 31

Stuck

Question 32

Stranguated

Answer 32

Blood supply is disrupted leading to necrosis

Question 33

What do the paraxial mesoderm form

Answer 33

Skeletal muscle Vertebra Cartilage

Question 34

What does the intermediate mesoderm go onto form

Answer 34

Kidneys | Gonads

Question 35

What does the ectoderm go onto form

Answer 35

Nerve tissue | Epidermis

Question 36

What does the foregut form

Answer 36

Oesophagus to 2nd part of duodenum where bile duct joins

Question 37

whAt does the mid gut go onto form

Answer 37

Distal duodenum to proximal transverse colon

Question 38

What does the hindgut go onto form

Answer 38

Distal 2/3 transverse colon to upper anal canal

Question 39

What is the Vitelline duct

Answer 39

Connects the midgut to the yolk sac

Question 40

Splanchnopleuric mesoderm

Answer 40

Combination of endoderm and splanchnic portion of mesoderm

Question 41

Somatopleuric mesoderm

Answer 41

Combination of somatic mesoderm and endoderm

Question 42

What is the intraembryonic coelom

Answer 42

Space between somatipleuric and splanchnopleuric mesoderm which gives rise to the abdominal and thoracic cavity

Question 43

What is a vittelibe cyst

Answer 43

When there is a small swelling

Question 44

what is a vitteline fistula

Answer 44

When the vitteline duct is completely intact

Question 45

What is included in the hind gut

Answer 45

``` Distal 1/3 transverse colon Descending colon Sigmoid colon Rectum Superior anal canal Bladder epithelia ```

Question 46

What connects teh lesser sac to teh greater sac

Answer 46

Foramen of Winslow

Question 47

What gut related landmark marks the start of the midgut?

Answer 47

The point at which the common bile duct and major pancreatic duct enter the duodenum

Question 48

Once fully developed, what is the relative position of the small and large bowel sections of the midgut?

Answer 48

The large bowel lies to the right of the small intestine | Transverse colon lies superior to proximal small bowel

Question 49

During the embryology of the gut, what does the cranial portion of the intestinal loop develop into?

Answer 49

small intestine

Question 50

If the Caecum did not ‘descend’ during development of the midgut, where would it lie with the abdominal cavity?

Answer 50

under the liver | right upper quadrant

Question 51

If there is a problem during the physiological herniation of the midgut, and it undergoes a single 90- degree clockwise rotation (as viewed from the front), the final layout of the gut will be different to normal. Briefly describe this difference.

Answer 51

Transverse colon will lie behind the proximal small bowel, instead of in front of it

Question 52

Why are there often more problems with the development of the intestines in Gastroschisis than with an omphalocoele?

Answer 52

With a gastroschisis (a defect in the formation of the anterior abdominal wall) the intestines are not covered in a layer of peritoneum and so are exposed to the amniotic fluid. This stunts their development. With an omphalocoele the intestines are covered in peritoneum inside the umbilical cord (not exposed to amniotic fluid).

Question 53

. How rotation of the midgut during development results in the transverse colon lying superior to the duodenum?

Answer 53

The initial layout of the intestinal loop involves cranial and caudal segments The cranial section (superior section) develops into the small intestine and the caudal section (inferior section) develops into the large intestine There follows a series of three 90-degree counter clockwise (as viewed from the front) rotations of the gut (while it is herniated) This brings the caudal section initially to the left (1st rotation), then superior (2 rotation) and then to the right (3rd rotation) Having followed this rotation the large intestine that develops from the caudal part of the intestine loop has been dragged over the top of the small intestine (and duodenum) and then to the right.