Embryology Flashcards
What germ layer does the heart derive from?
Visceral Mesoderm (Splanchnic mesoderm) The inner lining of the heart, lymphatic and blood vessels, develop from endothelium.
What day does the an endocardial tube develop?
Day 19
Where does a cardiogenic region start to develop by forming a horseshoe-shaped area?
Splanchnopleuric mesenchyme on either side of the neural plate
What are the forerunners of blood cells and vessels?
Formed from cardiac myoblasts and blood islands
Foramen secundum is significan for?
Allows shunting of blood from left to right atrium
What forms the foramen ovale?
The advanced edge of septum secundum
Septum primum function
The septum primum divides the atria into right and left. It acts as a unidirectional flutter valve. Blood only can flow from right atrium to left
What gives rise to the aortic arches
Truncus arteriosus
Where do progenitor heart cells migrate from?
Progenitor heart cells migrate from ectoderm, down the primitive streak into splanchnic mesoderm. This section is called the primary heart field.
What forms the primary heart field?
Left ventricle, atria and part of the right ventricle
Where does the rest of the right ventricle derive from?
Secondary heart field consisting of cardiac myoblasts and blood islands
What tubes join among themselves when the embryo “folds” laterally
Dorsal aortae and endothelial tubes; fuses on day 22
Where does the descending aorta come from?
Dorsal aortae
What structure in day 18 does the heart tube form from?
Endothelial tubes
What forms from the Sinus venosus
It is incorporated into the wall of the right atrium to form a smooth part called the sinus venarum. The sinus venosus also forms the SA node and the coronary sinus.
