Lecture 17: Formation of Body Cavities Flashcards Preview

Bree - Structures > Lecture 17: Formation of Body Cavities > Flashcards

Flashcards in Lecture 17: Formation of Body Cavities Deck (30):
1

when does formation of intraembryonic ceolom start

early in 4th week

2

what happens with lateral body folding

amnion engulfs entire embryo, yolk sac pinched off to form the gut

3

what are the embryonic body cavities initially

pericardial and peritoneal, connected by 2 pericardio-peritoneal canals

4

parietal layer vs visceral layer mesoderm

parietal = somatic
visceral = splanchnic

5

mesentery

a double layer of peritoneum that connects an organ to the body wall

6

what travels in the mesentery

blood vessels and nerves

7

dorsal mesentery

suspends caudal foregut, midgut, and hindgut in the peritoneal cavity

8

ventral mesentery

dissapears except in the proximal foregut (stomach and proximal duodenum)

9

arterial supply to primitive gut

celiac (foregut), superior mesenteric (midgut), inferior mesenteric (hindgut)

10

communication between intra and extraembryonic coelom

provides space for physiologic herniation of the midgut (intestinal folds happen in extra), closes at week 10 when intestines have returned to the abdomen

11

division of embryonic body cavity

pleuropericardial folds

12

what do pleuropericardial membrans contain

cardinal veins and phrenic nerves

13

what separates pericardial and pleural cavities

pleuropericardial membrans - fuse with mesenchyme ventral to esophagus to separate the cavities

14

4 EMBRYONIC components of diaphragm

septum transversum, pleuroperitoneal membranes, dorsal mesentary of esophagus, muscular in growth from lateral body walls

15

septum transversum

mesoderm of central tendon of diaphragm, begins cranial to heart, migrates via craniocaudal folding to separate heart from liver

16

where does the pleuroperitoneal membrane grow in from

lateral body walls

17

what does the pleuroperitoneal membrane fuse with

dorsal mesentery of esophagus and septum transversum

18

what closes pleuroperitoneal openings

myoblasts that migrate into the membrane

19

pleuroperitoneal membranes effect on fetal vs adult

large in fetal, small in adult

20

dorsal mesentery of esophagus

forms median portion of diaphragm

21

crura

pair of muscle bundles that form from myoblasts that have migrated into dorsal mesentary

22

muscular ingrowth of lateral body wall

expanding pleural cavities divide body wall into external and internal layer

23

external vs internal layer

external : definitive body wall
internal: peripheral diaphragm

24

what does muscular ingrowth of lateral body wall create

costodiaphragmatic recesses/angles

25

innervation of diaphragm

C3-4-5

26

phrenic nerve

2, motor and sensory innervations

27

CDH

congenital diaphragmatic hernia

28

closure timing of diaphragm

right closes before left

29

what happens in a CDH

abdominal viscera herniate from abdomen into chest

30

explain the formation of the diaphragm

1) septum transversum (mesoderm) between heart tube and liver is precursor to central tendon of diaphragm
2) paired pleuroperitoneal membranes (somatic mesoderm) develop from dorsal and dorsolateral body wall
3) dorsal mesentery of esophagus invaded by myoblasts and forms crura
4) body wall contributes muscle to peripheral portions of definitive diaphragm