Flashcards in CVS 2 Embryology- Early Development of the CVS Deck (20):
What develops from the cardiogenic field?
heart, blood vessels and blood cells
When is the cardiogenic field created?
Where does the cardiogenic field lie before embryonic folding?
the cranial end
What does lateral folding do?
create the heart tube
What does cephalocaudal folding do?
bring the tube into the thoracic region
When does the pair of endocardial tubes develop?
3rd week of development
What are the different parts of the primitive heart tube?
Why does the looping (primitive heart tube bends) and when does it happen?
Continued elongation results in bending.
Begins around day 23 and finishes around day 28
What sinus does looping create?
Transverse pericardial sinus
How does the sinus venosus develop?
R and L horns orginally equal size
Venous return shifts to RHS so left sinus horn recedes
Right sinus horn ansorbed by enlarging RA
What does the right atrium develop from? What does it recieve?
Most of primitive atrium
Receives venous drainage from body (venae cava) and heart (coronary sinus)
What does the left atrium develop from?
small portion of primitive atrium
absorbs proximal parts of pulmonary veins
recieves oxygenated blood from lungs
How is oblique sinus formed?
as left atrium expands absorbing pulmonary veins
How does fetus recieve oxygenated blood?
via placenta and umbilical vein. Returns to placenta via umbilical arteries
What is the ductus arteriosus?
shunt in fetal circulation between pulmonary trunk and aorta. Most blood doesnt pass through right ventricle and pulmonary trunk, it moves into left atrium but some must pass through to allow the muscle to develop
How do the aortic arches begin in the early arterial system?
a bilaterally symmetrical system of arched vessels numbered 1,2,3,4,6
What do the 4th arches form?
L- arch of aorta R- proximal part of right subclavian artery
What do the 6th (pulmonary) arches form?
R-right pulmonary artery L-left pulmonary artery and ductus arteriosus
What are the recurrent laryngeal nerves?
the nerve corresponding to the 6th arch moving down into chest then back up to larynx, controlling qualities of voice