Division of the Primitive Body Cavity: Formation of the Diaphragm; Establishment of the Major Systems and Structures Flashcards
Define epicardium
visceral serous pericardium that lines the heart surface
Define fibrous pericardium
Where the pleuropericardial membranes draw together like curtains to separate the pericardial cavity from the pericardioperitoneal canals and fuse with the mediastinum at the midline (parietal pericardium on one side, parietal pleura on the other)
Define parietal serous pericardium
lines the pericardial cavity surrounding the heart
Define mediastinum
the splanchnic mesoderm mass that separates the lungs
What 4 tissues contribute to the formation of the diaphragm?
- septum transversum
- mesenteries of the esophagus
- pleuroperitoneal membranes
- muscles from the body wall
How does the diaphragm change position during development?
dorsal growth is greater than ventral growth; diaphragm is pulled down in the back
Why is the phrenic nerve so long in an adult?
dorsal growth is greater than ventral growth; phrenic nerve gets pulled along with dorsal growth/diaphragm
What is congenital diaphragmatic hernia? What can it lead to?
when there is a failure in the pleuroperitoneal membrane to form, leaving a persistent opening in the diaphragm, the intestines bulge up into the thoracic space, compressing the lung so it cannot grow, leading to lung hypoplasia. PROBLEM WHEN BORN!
What are the fates of the original dorsal and ventral mesenteries of the peritoneal cavity?
the original ventral mesentery breaks down
the original dorsal mesentery remains
Describe the origins of the embryonic liver.
An ENDODERMAL liver bud (hepatic diverticulum) forms in the foregut and expands into the septum transversum.
Name the ventral mesenteries that attach to the liver.
Falciform ligament, lesser omentum
Describe the attachments of the ventral mesenteries that attach to the liver.
The lesser omentum is where the foregut gave rise to the liver, and the falciform ligament attaches the liver to the ventral body wall.
What forms from the intermediate mesoderm?
nephrogenic cords
Name the derivatives of the endoderm.
foregut, midgut, hindgut and all of their diverticula: thyroid lower respiratory tract epithelium liver hepatic cords gallbladder pancreas pharyngeal pouches (block 4)
Is umbilical artery blood oxygenated or deoxygenated?
deoxygenated
Is umbilical vein blood oxygenated or deoxygenated?
oxygenated
Where do the vitelline veins come from?
yolk sac
Where to the umbilical arteries go to?
placenta
What is the sinus venosus?
Where venous blood pools from vitelline, umbilical, and common cardinal veins
What arteries go to the embryo?
The Dorsal Intersegmental arteries, which branch off of the 2 dorsal aortae
What do the endocardial heart tubes form?
The ENDOCARDIUM of the heart (inner lining of heart)
What is the origin of myocardium?
mesoderm surrounding heart tubes
What spinal nerves supply the diaphragm?
C3, 4, 5 (phrenic nerve)
What are urogenital ridges?
Bulges where the nephrogenic cords are pushing mesoderm ahead of them into the peritoneal cavity
