Thoracic embryology

Question 1

Peritoneal Cavity

Answer 1

abdominal region

Question 2

Intraembryonic coelom

Answer 2

horse-shoe shaped cavity 
Has 3 embryonic cavities 
1. peritoneal cavity 
2. Pericardial cavity 
3. Pleural Cavity

Question 3

Pericardial cavity

Answer 3

heart region

Question 4

Where does the pericardial cavity move?

Answer 4

starts above the everything and moves ventrocaudally, anterior to the foregut

Question 5

Pleural Cavity

Answer 5

lung region

Question 6

What layers are in the pleural cavity

Answer 6

parietal pleura and visceral pleura

Question 7

visceral peritoneum

Answer 7

layer on the organ

Question 8

parietal peritoneum

Answer 8

layer on the embryo/ body wall

Question 9

Umbilical hernia

Answer 9

Guts grow so fast that the somatic mesoderm (part of intraembryonic coelom) doesn’t grow fast enough and the guts herniate for a short period of time

Question 10

somatic mesoderm

Answer 10

outer layer of the developing mesoderm
body wall muscles
contains peritoneal cavity and pericardial cavity

Question 11

splanchnic mesoderm

Answer 11

inner layer of the developing mesoderm

smooth muscle of the gut tube

Question 12

pericardioperitoneal canal

Answer 12

future pleural cavities

Question 13

2 ridges that form from lungs moving somatic mesoderm

Answer 13

Cranial ridge = pleuropericardial folds

Caudal ridge = pleuroperitoneal folds

Question 14

pleuroperitoneal folds

Answer 14

Contains pleuroperitoneal membrane
partitions pleural cavity from peritoneal cavity
Forms the posterior portion of the diaphragm

Question 15

Pleuropericardial folds

Answer 15

contains pleuropericaridal membrane
partitions pleural cavity from pericardium
forms the primitive mediastinum

Question 16

Mesentery

Answer 16

double layer of peritoneum connects organ to body wall

houses nerves and vessels

Question 17

Dorsal mesentery

Answer 17

permanent structure
suspends foregut, midgut, and hindgut in peritoneal cavity
divides peritoneal cavity into right and left halves (thoracic cavity)
median portion of the diaphragm

Question 18

Ventral mesentery

Answer 18

Degenerates to provide large space for peritoneal cavity (abdominal region)
any mesentery associated with liver in the adult is this!
Becomes lesser omentum, Falcifrom ligament (suspends the liver) and visceral peritoneum surrounding the liver

Question 19

What makes up the diaphragm

Answer 19

septum transversum
pleuroperitoneal membranes
Dorsal mesentery
muscular ingrowth from lateral body wall (somatic mesoderm)

Question 20

Septum transversum

Answer 20

central tendon of the diaphragm
shelf of mesoderm the heart sits on
fuses with dorsal mesentery

Question 21

pleuroperitoneal membranes

Answer 21

primordial diaphragm

separates the lungs

Question 22

Innervation of the diaphragm

Answer 22

Cervical somites 3,4,5 gives rise to the phrenic nerve

motor and sensory fibers to the diaphragm

Question 23

Costodiaphragmatic recess

Answer 23

pleura dives down laterally on right and left side
gives dome shape to the diaphragm
very small after birth because of lungs expanding

Question 24

Congenital Diaphragmatic Hernia

Answer 24

presence of abdominal viscera in thoracic cavity

Question 25

Posterolateral Defect (congenital diaphragmatic hernia)

Answer 25

pleuroperitoneal membrane didn’t fuse with the other 3 parts of the diaphragm so the pleural and peritoneal cavities are continuous

Question 26

Congenital Hiatal Hernia

Answer 26

upper part of the stomach is in the thoracic cavity