Development of the Heart Flashcards
What is the first major system to function in an embryo?
The cardiovascular system
Which layer is the heart derived from?
Mesoderm
What is the heart at week four?
A single heart tube
What are the three veins that drain into the single tube heart?
Vitelline
Umbilical veins
Common cardinal veins
What is the part of the heart called that the three veins drain into?
Sinus venosus
What does the right vitelline vein become?
Hepatic portal vein
What do the vitelline veins carry?
Poorly oxygenated blood from yolk sac
What do the umbilical veins carry?
Well-oxygenated blood from chorionic sac
What does the left umbilical vein form?
Ductus venosus in the liver
What is the function of the ductus venosus?
Allows oxygenated blood to bypass the liver and enter the sinus venosus
What do the cardinal veins carry?
Poorly oxygenated blood from the body of embryo
What is the main drainage from the body of the embryo?
Cardinal veins
What do the anterior and posterior cardinal veins drain respectively?
Anterior: Cranial portion
Posterior: Caudal portion
What does the sinus venosus develop into?
SVC
IVC
Coronary sinus
What does the bulbus cordis contribute to the formation of?
Right ventricle
Where is the bulbus cordis located?
Above ventricle and below the truncus arteriosus
What does the truncus arteriosus form?
Proximal portion of aorta and pulmonary trunk
Which way does the heart rotate?
Counter clockwise
To the right
What becomes the sinus venarum?
Right sinus horn
What do the atrioventricular endocardial cushions do?
Form a column dividing the left atrium and ventricle from the right atrium and ventricle
How is the interventricular septum created?
The interventricular septum grows upwards towards the endocardial cushion and the endocardial cushion grows down to form the interventricular septum
What is the first step in atria separation?
The septum primum moves from the superior portion of the hear towards the endocardial cushions but does not touch leaving foramen primum
What happens to the septum primum?
It completely closes off and apoptosis occurs forming the foramen secundum to allow blood to flow from the right to the left atrium
How is the septum secundum formed?
Sinus venosus is pulled into the right atrium and bunches up against the foramen secundum forming the foramen ovale along with the septum primum
