Embryology Body Cavities

Question 1

regression of ventral mesentary

Answer 1

peritoneal cavity is no longer divided into right and left halves; one space

Question 2

transverse folding accomplishes

Answer 2

horse shoe to donut. communication between pericardial cavity, plueroperitoneal canals, and peritoneal cavity, as well as establishing the dorsal and ventral mesentery (double peritoneum) ventral mesentary regresses except for caudal forgut for liver

Question 3

dorsal mesentary

Answer 3

double layer of visceral peritoneum

Question 4

location of pericardioparietal canals

Answer 4

laterally to forgut, dorsal to septum transversum

Question 5

septum transversum is made of

Answer 5

visceral/splanchnic mesoderm

Question 6

growth of lung buds into pericardioperitoneal canal

Answer 6

production of membranous ridges produces. superior to developing lungs/cranial=plueropericardial membrane
caudal ridges=plueroperitoneal membranes

Question 7

two membranes formed by developing lung buds

Answer 7

plueroperitoneal membrane

pleuropericardial membrane

Question 8

what do the pleuropericardial membranes contain

Answer 8

common cardinal veins, and phrenic nerves

Question 9

where do the two plueropericardial membranes fuse

Answer 9

with each other at the midline and the root of the lungs.

Question 10

what is the adult structure of the pleuropericardial membranes

Answer 10

fiberous pericardium

Question 11

what do the pericardioperitoneal canals form in the adult

Answer 11

pleural cavities

Question 12

how are the pleuroperitoneal membranes formed

Answer 12

by the developing lungs and pleural cavities expanding and invading the body walls

Question 13

what leads to the complete separation of the pleural and peritoneal canal

Answer 13

ventro-medial extension of the plueroperitoneal folds and fusion with the mesentary (crura) of the esophagus and septum transversum, assisted with myoblasts in pleuroperitoneal membranes

Question 14

myoblasts of pleuroperitoneal membranes form the

Answer 14

postero-lateral regions of the diaphram

Question 15

which plueroperitoneal cavities closes first and why

Answer 15

right before left, due to liver.

Question 16

as pleural cavities expand ventrally around heart…..

Answer 16

they split tissue into thoracic wall and inner player that forms the pleuropericardial membranes

Question 17

4 components of the diaphram

Answer 17

septum transversum
plueroperitoneal membrane
dorsal mesentary of esophagus=crura of diaphram
myoblasts/ muscles from lateral wall

Question 18

septum transversum from?

Answer 18

mesodermal mass in cervical region at somite 3-5, thick incomplete partition of peritoneal and pericardial cavities

Question 19

phrenic nerves form….

Answer 19

deep to mediastinal pleura

Question 20

phrenic nerve travels with….

Answer 20

diaphram as it descends. phrenic nerve 3,4,5/

Question 21

separation of pericardial cavity from pleural cavities

Answer 21

pleuropericardial membrane fusing with mesenchyme ventral to esophagus

Question 22

importance of connection of distal lateral limb to the chorionic cavity

Answer 22

allows midgut to herniate and develop outside the embryo