Cardiovascular - Session 2 Flashcards
Name the embryonic germ layer that contributes to the cardiovascular system.
The lateral plate mesoderm
Explain how folding contributes to the development of the cardiovascular system.
Lateral folding - creates a heart tube
Cephalocaudal folding - brings the tube into the thoracic region
What cavity does the primitive heart tube sit in?
The pericardial cavity
Name, in order of blood flow, the sections of the primitive heart tube.
Sinus venosus, Atrium, Ventricle, Bulbus cordis, Truncus arteriosus and aortic roots.
Why does lopping occur?
Primitive heart tube expands and uses all of the space in the pericardial cavity
What does looping do?
Makes cephalic portion go ventrally, causally and to the right
Makes caudal portion go dorsally, crainally and to the left
Also brings the outflow and inflow next to each other with the arteries in front of the veins.
What does the atrioventricular canal do?
Allows the atrium to communicate with the ventricle.
What does the right atrium develop from?
Most of the primitive atrium and the sinus venosus.
Receives venous drainage from venae cava and coronary sinus.
What does the left atrium develop from?
A small amount of the primitive atrium and the proximal sections of the pulmonary veins.
Receives oxygenated blood from the lungs.
What is the name of the foetal shunt that bypasses the lungs?
The ductus arteriosus
Why does a small amount of blood need to pass through the pulmonary trunk during foetal shunts?
Because it is a muscle it will undergo muscle atrophy if not used.
What are the aortic arches?
Blood vessels from which the great vessels form. They are numbered 1-4 and 6 and all have their own corresponding nerve.
What does the 4th aortic arch develop into?
Right - proximal section of right subclavian artery.
Left - arch of aorta.
What does the 6th aortic arch develop into?
Extra point - what nerve corresponds to it and why is it special?
Right - right pulmonary artery.
Left - left pulmonary artery and ductus arteriosus.
It’s nerve is the recurrent laryngeal nerve. Special as it has to turn back on itself due to the heart descending; becomes hooked on the shunt between the pulmonary trunk and aorta.
