Body Cavities, Mesentery, Diaphragm

Question 1

germ layer for all smooth muscle, CT

Answer 1

splanchnic mesoderm

Question 2

germ layer for all epithelia related to gut

Answer 2

endoderm

Question 3

germ layer for stomodeum and proctodeum

Answer 3

ectoderm

Question 4

what forms the abdominal cavity?

Answer 4

intraembryonic coelem as it is enclosed by body wall closing around it

Question 5

in general, origin of mesentery?

Answer 5

remnant of the yolk sac membrane

Question 6

4 derivatives of diaphragm and what they become in adult

Answer 6

1. septum transversum -> central tendon
2. pleuroperitoneal folds -> not much in adult
3. mesentery of esophagus -> crura
4. muscular ingrowth of body wall -> muscular diaphragm

Question 7

what forms the pericardium?

Answer 7

pleuropericardial folds from the pleuroperitoneal folds

Question 8

start and stop points for kidneys

Answer 8

start in pelvis, but are elevated into abdominal cavity due to growth of body wall

Question 9

eventration of diaphragm

Answer 9

thin membrane b/w organs and thorax, but essentially a hernia

Question 10

congenital diaphragmatic hernia

Answer 10

born without a diaphragm or with holes in diaphragm

Question 11

why do the curvatures of the stomach form?

Answer 11

different growth of dorsal and ventral stomach

Question 12

degree of rotation of large intestine

Answer 12

270

Question 13

origin of spleen

Answer 13

condensation of mesenchyme

Question 14

what mesenteries/ligaments come from ventral mesentery?

Answer 14

• lesser omentum
• falciform ligament
• coronary/triangular ligaments

Question 15

what mesenteries/ligaments come from dorsal mesentery?

Answer 15

• gastrosplenic ligament
• splenorenal ligament
• gastrocolic ligament
• greater omentum
• mesointestine
• mesoappendix
• transverse mesocolon
• sigmoid mesocolon

Question 16

how do neurovascular bundles reach the intraperitoneal viscera?

Answer 16

through the mesentery

Question 17

which vagus becomes anterior and which posterior?

Answer 17

left -> anterior

right -> posterior

Question 18

how many layers in greater omentum?

Answer 18

4 layers that fused together to form an apron

Question 19

lesser omental bursa

Answer 19

sac behind the stomach

Question 20

foramen of winslow

Answer 20

pokes a hole behind the stomach into the lesser omental bursa

Question 21

the torsion of the gut tube causes what organs to become secondarily retroperitoneal?

Answer 21

duodenum and pancreas

Question 22

what ligaments compose the lesser omentum?

Answer 22

hepatogastric and hepatoduodenal

Question 23

where does the pancreas come from?

Answer 23

ventral and dorsal pancreatic buds

Question 24

gastroschisis

Answer 24

when abdominal wall doesn’t zip closed around the guts

Question 25

Hirschsprung’s disease

Answer 25

congenital megacolon - lack of enteric neurons -> lose peristaltic waves -> gut backs up -> megacolon

Question 26

how does the cloaca become the UG sinus and the rectum?

Answer 26

the urorectal septum grows into it and splits it into two compartments