Embryonic cardio development Flashcards
Where do Vitelline veins come from and what do they give rise to?
They come from the yolk sac and drain the gut tube. They give rise to Portion of inferior vena cava, portal vein, splenic vein, superior mesenteric vein and inferior mesenteric vein
What does the Umbilical Vein do?
It carries O2 blood from placenta to nourish the embryo.
What do Cardinal Veins do and what do they give rise to?
the anterior and posterior cardinal veins form main drainage system of the embryo. Eventually they give rise to brachiocephalic vein, superior vena cava, and a portion of inferior vena cava.
When does the heart remodel itself so that all systemic blood flows into the future right atrium?
Between weeks 4 and 8
How many arteries become modified and rearrange to form adult vascular pattern?
Five pairs
What does splanchnic mesoderm form?
It forms the muscle and connective tissue layers, blood vessels and peritoneal components (mesothelium, connective tissue)
Where does the primitive gut tube come from?
It comes from the endoderm lined yolk sac, which becomes folded as the rest of the body folds.
What does endoderm give rise to?
Epithelial cells of the gut tube( pharyngeal foregut, digestive system and respiratory system) and associated glands
What is the vitelline duct and what does it become?
The communication between the yolk sac and the midgut. Eventually it becomes the core of the umbilical cord
Where does the septum primum originally form?
The dorsal roof of the atrial chamber
Where does the septum primum grow after forming?
Towards the Atrioventricular canal
What divides the AV canal into right and left atrioventricular orifices?
The dorsal and ventral endocardial cushions( which becomes the AV septum)
What is the interatrial foramen primum?
The space between the caudal edge of the septum primum and the endocardial cushions
What does the interatrial foramen primum do?
acts as a shunt, letting blood pass between the right and left atrium
The opening left in the septum secundum is called the
foramen ovale
What does the remaining portion of the primary septum become?
valve of foramen ovale
What happens because the of the fall of pressure in the right atrium after birth?
Fall of pressure in the right atrium will result in the valve of the foramen ovale pressing against the secondary septum
Where do the cells that partition the outflow tract come from?
They are neural crest cells that originated in the hindbrain, they migrated through the pharyngeal apparatus
Initially, what partitions the single chambered outflow tract?
the conotruncal ridges partition it into aortic and pulmonary channels. The ridges come from neural crest mesenchyme
In what fashion do the truncoconal ridges develop?
in a spiral fashion
In what direction to the conotruncal ridges fuse?
In a cranial to caudal direction
What is the conotruncal septum?
the septum betwee the aortic and pulmonary outflow tracts
How does the interventricular septum form?
From expansion of apical aspects of the right and left ventricle. The growth prodtrudes into the lumen towards endocardial cushions, but stops before getting there.
When the apical aspects of the right and left ventricles expand into the lumen of the heart, growth stops just before reaching the endocardial cushions, the space left between them is called?
Interventricular foramen
Which tissues are involved in the membranous part of the ventricular septum?
Right and left conus cordis swellings, endocardial cushion, neurall crest cells.
What causes complete septation of the ventricles?
The membranous interventricular septum
Describe the flow of blood in fetal circulation
- Umbilical vein 2. Ductus venosus 3. Oval foramen 4. Ductus arteriosus 5. Umbilical arteries
Describe flow of blood after birth
- Ligament teres hepatis 2.Ligamentum venosum 3. Closed oval foramen 4. ligamentum arteriosum 5. superior vesical artery
Adult structure of Umbilical arteries
Medial umbilical ligaments and superior vesical arteries
Umbilical vein Adult structure
Ligamentum teres
Ductus venosus Adult structure
Ligamentum venosum
Ductus arteriosis Adult structure
Ligamentum arteriosum
Foramen ovale adult structure
Fossa ovalis
Where is the primary heart field initially?
In splanchnic layer of lateral plate mesoderm
What are cardiac progenitor cells specified to make?
Left and right sides of heart, Atria, left Ventricle, and part of Right Ventricle
What does the secondary heart field form?
Remainder of RV and outflow tract consisting of conus cordis and truncus arteriosus.
In early development of the heart the embryo folds laterally, what happens to the caudal regions of the endothelial heart at this point?
They merge, the resulting tube kind of looks like a butt and legs
What does the heart tube that looks like a butt and legs consist of?
An inner endothelial lining and an outer myocardial layer
What does cardiac jelly do?
separates endothelium from myocardium
After formation of cardiac jelly, what does the heart tube consist of?
Epicardium (visceral epicardium) myocardium and endocardium. The transverse section looks like :0
What does the visceral epicardium make?
it is responsible for forming coronary arteries
Sinus venosus
consists of left/right sinus horns that initially receive 3 paired veins
Primitive atrium
forms trabeculated part of right atrium and all of left atrium
primitive ventricle
forms trabeculated left ventricle only
Bulbus cordis
Proximal: right ventricle’
Distal(conus cordis):smooth part of the right conus arteriosus and left ventricle(vestibule)
Truncis Arteriosus
Proximal ascending aorta, pulmonary
During cardiac looping, in what direction does the bulbous cordis move?
It is displaced caudally ventrally and to the RIGHT as it grows
During cardiac looping, in what direction does the primitive ventricle move?
to the LEFT
During cardiac looping in what direction does the primitive atrium move?
dorsally and cranially
During cardiac looping, where does the cephalic portion of the heart move in general?
Ventral, Caudal, and to the RIGHT
During cardiac looping, where does the Caudal portion of the heart move in general?
Dorsal, cranial, and to the LEFT
after cardiac looping, what is the relationship between the caudal inflow and the outflow track?
Initial caudal inflow is positioned DORSAL to the outflow track
After cardiac looping where is the heart?
The left side
After cardiac looping where is the outflow truncoconal region?
The mid-line
How is is the heart re-aligning the ventricles and atria while the AV septum forms?
It aligns the LEFT av canal with the LEFT atrium and ventricl and the RIGHT av canal with the RIGHT atrium and ventricle
