Cardiovascular Development (Exam II) Flashcards
What is the cardiovascular system derived from?
Angioblastic Tissue (which arises from the mesenchymal) Primitive mesenchymal cells give rise to CVS
What is the process of blood vessel development called?
Angiogenesis
What is the cardiogenic field? What is its purpose?
Horseshoe shaped structure located around anterior and lateral portions of the neural plate.
It is the area of blood forming cavities in the visceral mesoderm where hemangioblasts will eventually coalesce and forms he primitive heart, blood vessels and blood cells.
The caudal portions of the endocardium heart tubes will make contact with what..?
The venous system
What happens when the caudal portion of the endocardium heart tubes fuses and becomes surrounded by myoblasts?
It forms myocardium and thus the Cardiac Tube.
What are the 3 components of the cardiac tube (from where the tube first fuses heading towards the venous system)
Bulbis cordis (precursor to right ventricle), Ventricle (Left ventricle precursor), Atrium
What happens during loop formation?
The heart twists around itself. This in combination with the division of the cardiac tube into 4 chambers results in heart formation.
Describe fetal blood circulation.
Blood from placenta is carried to the fetus through the umbilical vein –> enters ductus venosus (which bypasses the liver) and is carried up to the vena cava and into the right atrium –> some blood passes through foramen ovale and enters left atrium –> Then enters aorta and is pumped to the body.
The blood that does not go through the foramen ovale into the left atrium is pumped up into the pulmonary artery but the ductus arteriosus pushes that blood back into the aorta, bypassing the pulmonary system.
Some blood moves from aorta through internal Iliad arteries to umbilical arteries and reenters the placenta where CO2 and other waste products are taken up and enter maternal circulation.
What are the divisions of the truncus arteriosus? What are they divided by?
Outflow tracts of: Ascending aorta and pulmonary trunk.
They are divided by a spiral septum.
Review the partitioning of the heart :)
:)
What serves as a valve for the foramen ovale?
Primary atrial septum -
What does the foramen ovale become?
Fossa ovalis
What are the changes that occur after birth that assists in the closure of the foramen ovale?
Lungs expand with first breaths - creates sudden decrease in vascular resistance in lungs and the blood pressure in the pulmonary circulatory system will decrease.
What happens when the 2 ridges of the spiral septum of the truncus arteriosus fuse? Why is it spiral?
It forms the Aorto-Pulmonary Septum. It has spiral formation because that ensures the blood from the right ventricle flows into pulmonary trunk and blood in the left ventricle flows into the ascending aorta.
What would happen if the aorto-pulmonary septum was straight and not spiral?
It would case Transposition of the Great Vessels.
Deoxygenated blood from R ventricle would flow into the ascending aorta and highly oxygenated blood from the L ventricle would flow into the pulmonary trunk (lungs).
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