body cavities mesenteries and diaphram Flashcards
The lateral plate mesoderm divides into 3 things what are they?
- Somatic mesoderm
- Splanchnic Mesoderm
- Intraembryonic coelom
What is the intraembryonic coelom a precursor for?
- Pericardial cavity
- Pericardioperiteonal canals
- Peritoneal cavities
What structures come from the somatic mesoderm?
Parietal layer of serous membranes of peritoneal, pleura and pericardial cavities
What structures arise from the splanchnic mesoderm?
Visceral layer of lungs, heart, abdominal organs
- CT and smooth muscle of Gi and Respiratory tract
Lateral folding is a result of what?
Folding of somatic mesoderm
When the heart forms outside the thoracic wall its called?
Ectopia cordis with cleft sternum
- lateral doesn’t meant cephalic fold
- incompatible
What connects the pericardial and peritoneal cavities and what does it give rise to later?
Pericardioperitoneal canal- on each side of the foregut
Pleural cavities
An evisceration of abdominal contents through a fissure in the anterior abdominal wall above or below the umbilicus is what? Cause?
Congenital umbilical hernia (Covered by skin)
- wall body anomaly and myotome migration
What is Gastroschisis? cause?
Eviceration of abdominal contents usually on right
- More frequent in cocaine use mothers
- lateral folding and myotome anomaly
- basically umbilical hernia without covering of skin or fascia
What is extrophy of the bladder?
Urinary bladder open out onto body wall
- Hemipenis and hemiscotum too
- myotome migration involved
Pericardial cavity is carried where compared to the foregut?
Ventrocaudally
What suspends the foregut, hind and midgut?
Dorsal mesentery
- also carries vessels and nerves
What happens to the ventral mesentery
It disappears except in the region of the stomach, proximal duodenum, and the liver where is remains as the lesser omentum and the falciform ligament.
What is the significance of the pleuropericardial folds (membranes)?
Divides the thoracic cavity into the pericardial cavity and pleural cavities
- does this by dividing the intraembryonic coelom
What other structure does the pleuropericaridal folds create?
Fibrous pericardium
-surface cells form the serous membranes
What does the pleuropericardial folds contain?
Phrenic nerve
Common cardinal veins
What extends ventrally to fuse with the dorsal mesentery of esophagus and the transverse septum? What does it separate?
Pleuroperitoneal membranes
- pleural cavity from the peritoneal cavity
- closes pericardioperitoneal canal
How are the post lateral regions of the diaphragm formed ?
Myoblasts of transverse septum migrate into pleuroperiteonal membranes
Where is the phrenic nerve located?
Between the fibrous pericardium and mediastinal pleura
What creates the central tendon of the diaphragm?
transverse septum and ventral mesentery
What forms the lumbocostral and vertebrocostal trigones?
Pleuroperitoneal membranes
What forms the left and right crura of the diaphragm?
Dorsal mesentery of the esophagus.
- Motor branches of phrenic nerve carries from transverse septum myoblasts
What forms the costal portion of the diaphragm?
Lateral and dorsal body walls
- myoblasts from TS migrate into mesenchyme of lateral body wall
Where does the lateral costal margin of the diaphragm receive its innervation?
Sensory from lower intercostal nerves
How does the phrenic nerve get to the diaphragm>
Cervical somites 3,4,5 and thus cervical nerves 3,4,5 migrate into transverse septum which migrates down to form the central tendon
What is a congenital diaphragmatic hernia?
1/2200
- failure of the pleuroperitoneal folds to fuse with the other diaphragmatic components (usually the vertebrocostal or lumbocostal trigone)
what herniates in a congenital diaphragmatic hernia?
stomach spleen intestine into thoracic cavity
What are some symptoms of the womb and can the bay survive?
Polyhydraminios
- no because of hypoplastic lungs
- usually on left
What side does the congenital diaphragmatic hernia normally appear and why?
left
- because the pericardioperiteoneal canal is larger on the left
What is eventration of the diaphragm?
half diaphragm has defective musculature and abdominal viscera balloon in the thoracic cavity
- thus there is still a membrane and not due to lack of fusion but hypoplastic diaphragm
What causes a eventration of a diaphragm?
myoblast in the transverse septum dont migrate into the other components of the diaphragm or fails to migrate all together.
What are the 2 kinds of congenital esophageal hiatal hernias?
Sliding
Paraesophageal
what is a esophageal hiatal hernia
herniation of the stomach through the esophageal hiatus
- due to failure of esophagus to elongate
- increase risk for adult hiatal hernia
What is a retrosternal hernia?
Gut herniation between the sternum and diaphragm
