Lecture 3: heart development Flashcards
progenitor heart cells migrate and form
horseshoe-shaped primary heart field in the splanchnic layer of the lateral plate mesoderm
primary heart field gives rise to
left and right sides of the hear, atria, left ventricle, and part of the right ventricle
secondary heart field gives rise to
the remainder of the right ventricle and the outflow tract (conus cords and trunks anteriosus)
hemangioblasts
- once in the cardiac crest differentiate into hemangioblasts
- form blood cells and blood islands by vascular endothelial growth factor
endocardial heart tubes
- formed by islands of hemagioblasts
- lined with endothelium
merging of the heart tube
- as the embryo folds laterally the caudal regions of the heart tube merge
- inner endothelial lining and outer myocardial layer
cardiac jelly
- extracellular matrix secreted by the myocardium
- separates the endothelium from the myocardium
dorsal mesocardium
-initially attaches the heart tube to the dorsal side of the pericardial cavity
transverse paricardial cavity
formed by the break down of the central portion of the dorsal mesocardium
importance of the breakdown of the dorsal mesocardium
liberated the tube for further growth and bending
cranial end of the cardiac tube is attached to
the pharyngeal arches
caudal end of the cardiac tube is embedded in
the septum transversum
five heart dialations
- sinus venous
- primitive atrium
- primitive ventricle
- bublus cordis
- truncis arteriosus
sinus venous
left and right sinus horns that initially receive three paired veins
primitive atrium
forms traberculated part of the right atrium and all of the left atrium
pimitive ventricle
forms trabeculated left ventricle
atrioventricular canal
separates the primitive atrium and the primitive ventricle
bulcus cordis
- proximal: right ventricle
- distal (conus cordis): smooth part of the right (conus arteriousus) and left ventricle (aortic vestibule)
truncis arteriosus
proximal ascending aorta, pulmonary trunk
heart loops to the
right
area of rapid heart growth
proximal bulbus cordis and primitive ventricle
cardiac looping
displacement of the proximal bulbous cordis
caudally, ventrally, and to the right