Development of Bodily Coelom Flashcards
The coelom is formed by the splitting of the lateral mesoderm extending to the ____ and ____ but does not reach the level of the pharynx
thoracic and abdominal region
____ closes the coelom ventrally, except at the level of the ____
Lateral body folds
umbilicus
In the embryo, all regions of the intraembryonic coelom are continuous, the only partition is the ____ lying in a transverse plane between the sinus venosus and the liver
septum transversum
Dorsal to the septum transversum is the common ____ continuous with the peritoneal coelom
pleuropericardial cavity
Caudal growth of the ____ brings the lungs into the dorsal part of the pleuropericardial cavity near the level of the septum transversum and into cranial mediastinum
laryngotracheal groove
refers to any median partition commonly used in reference to the thoracic cavity
Mediastinum
Formation of the pericardial cavity and its separation from the pleural cavity is iniated by the ____ which grow medially and fuse
with the mediastinum ventral to the esophagus forming the pleuropericardial septum Pleural and pericardial cavities then formed
pleuropericardial folds
The diaphragm is composed of
two components:
septum transversum
caudal mediastinum sometimes called
dorsal mesentery
*DIAPHRAGM
(forms early during heart formation) that forms the central tendinous part of the diaphragm
septum transversum
*DIAPHRAGM
____ thru which the esophagus and caudal vena cava pass
caudal mediastinum (dorsal mesentery)
*DIAPHRAGM
Expansion of the ____ dorsoventrally causes
the roof of the pleural cavities to elevate on either side
caudal medistinum
*DIAPHRAGM
Final closure of the cavities is thru the growth of the ____ projecting the peritoneal cavity
pleuroperitoneal folds
*CLOACA
The ____ portion of the hindgut gives rise to the aboral portion of the transverse colon and the descending colon.
oral
*CLOACA
The more ____ portion of the hindgut gives rise to the rectum, and to the allantois and its derivatives.
aboral
The hindgut terminates in the ____, a caudal cavity lined by endoderm and sealed from the amniotic cavity by the ____ which is lined by endoderm and covered by ectoderm on the outside.
cloaca
cloacal membrane
*CLOACA
A layer of mesoderm that separates the allantoic duct and the hindgut.
URORECTAL SEPTUM
*URORECTAL SEPTUM
Divides the cloacal membrane into an ____ dorsally and a ____ ventrally.
anal membrane
urogenital membrane
- Continuous with the hindgut
- Becomes the rectum and most of the anal canal.
Dorsal chamber (of urorectal septum)