Cardiovascular Embryology Flashcards
from superior to inferior, the primitive heart tube is comprised of which six regions?
Aortic roots (arterial poles)
Truncus arteriosus
Bulbus cordis
Primitive ventricle
Primitive atrium
Sinus venosus (venous poles)
describe the process of heart tube looping
The bulbis cordis moves forward, down and right and the primitive ventricle moves backwards up and left
what is the fate of the left sinus horn of the sinus venosus?
Over time, the venous return shifts to the right side of the heart, causing the left sinus horn to recede and form the coronary sinus (responsible for the drainage of venous blood from the heart itself).
what is the fate of the right sinus horn of the sinus venosus?
The enlarged right sinus horn is absorbed by the growing right atrium and eventually forms part of the inferior vena cava in the adult.
what is the derivative of the 3rd aortic arch in adults?
Forms the common carotid artery and part of the proximal internal carotid artery.
what is the derivative of the left and right 4th aortic arch in adults?
Right arch forms the right subclavian artery
Left arch forms part of the arch of the aorta
what is the derivative of the left and right 6th aortic arch in adults?
Right arch forms the right pulmonary artery
Left arch forms the left pulmonary artery and the ductus arteriosus.
what does the ductus arteriosus develop into in adults?
ligamentum arteriosum
how does septation of the heart into right and left channels occur?
when endocardial cushions developing in the atrioventricular region expand to divide the heart.
describe the septation of primitive atria
- formation of septum primum which forms an ostium secundum.
- septum secundum growths down and forms foramen ovale.
-ostium secundum and formamen ovale allows left to right shunt.
describe the septation of primitive ventricles
The interventricular septum of the ventricles has two components; one muscular and one membranous.
The muscular portion grows upwards towards the fused endocardial cushions, but a small gap, the primary interventricular foramen, remains.
This gap is filled by the membranous portion of the interventricular septum, which is comprised of connective tissue derived from endocardial cushions.
describe the development of the outflow tract
Endocardial cushions also appear within the truncus arteriosus which grow towards each other.
As they grow towards each other they twist around each other and form a spiral septum, dividing the outflow tract into left and right sides.
the lungs are bypassed by which shunts?
foramen ovale
ductus arteriosus
how does oxygenated blood bypass the foetal liver?
achieved by passage through the ductus venosus, which is estimated to shunt around 30% of umbilical blood directly to the inferior vena cava.
what is the adult remnant of the ductus venosus?
ligamentum venosus
