CVS- Development Flashcards
What is the cardiogenic region?
Cardiac myoblasts and blood islands
Which germ layer do progenitor heart cells become?
Mesoderm
What is the benefit of cephalocaudal folding?
This positions the heart in the chest
What is the benefit of lateral folding to CVS development?
This joins the caudal regions of the paired cardiac tube.
What are the names of the sections of the primitive heart tube? From bottom upwards (caudal - cranial)
The SINUS VENOSUS recieves blood from the embryo This passes into the ATRIUM. Then passes up to the VENTRICLE Up to the BULBUS CORDIS then to the TRUNCUS ANTERIOSUS and out through the aortic roots
How does looping occur?
As the outflow tract lengthens the cardiac tube begins to bend
The cephalic portion bends ventrally and caudally and to the right
The caudal portion shifts dorsocranially and to the left
What leads to the formation of the transverse pericardial sinus?
And what is it?
Looping
It is the position of arteries in front of veins
Between the aorta and pulmonary artery infront and superior vena cava behind.
After looping how does the atrium communicate with the ventricles?
Via the atrioventricular canal
What incorporates into the primitive atrium to form the RA?
The right sinus horn
What is the LA developed from?
A small portion of primitive atrium, proximal parts of pulmonary veins.
Why is fetal circulation carried out through the placenta?
Because the lungs are the last body system to develop
What are circulatory shunts?
Small passages that direct blood to be oxygenated
What is the name of the shunt that bypasses the lungs from the pulmonary trunk to the aorta?
The ductus arteriosus
How does blood get from the IVC to the Right atrium?
Placenta to IVC by ductus venosus
IVC to RA
How does the arterial system begin?
As a bilaterally symmetrical system of arched vessels.
After looping of the heart what links the two chambers?
The atrioventricular canal
What grows to divide the AV canal into left and right channels
Endocardial cushions
How many septa and holes are involved in atrial septation?
2 septa and 3 holes
Describe atrial septation
The septum primum grows down towards the endocardial cushions
The ostium primum is the hole present before septum primum fuses
The ostium secundum appears before the OP closes
A second crescent shaped septum grows - septum secundum
The hole in this is called the foramen ovale
What is the foramen ovale used for?
Used as shunt in foetal circulation to allow blood flow from right to left
What is the adult remnant of the foramen ovale?
The fossa ovalis
What are the two components of the ventricular septation?
Muscular and membranous
How does the muscular portion of the ventricular septum grow?
Up towords the endocardial cushions
Leaves a Hole at the top called a primary interventricular foramen
How does the membranous portion of the ventricular septum form?
Derived from spiral septum this covers the primary interventricular foramen.
What is the fate of the ductus arteriosus?
Ligamentum arteriosus
What is the fate of the ductus venosus?
Ligamentum venosus
