Thorax 6 - Development of Heart and Great Vessels Flashcards
By what day in embryonic development is a heart required to drive circulation?
Day 18
From which embryonic layer does the heart originate?
Mesoderm
Why is the heart based slightly on the left of the thorax?
The 2 ends fold slightly to the right, bringing the apex of the heart round to the left
From which veins does the venous end receive blood?
Cardinal
Vitelle
Umbilical
Describe two ways in which narrowing between atria and ventricles ensues.
Kink in the tube during folding of the early heart
Endocardial cushions
What does the 1st aortic arch form?
Maxillary arteries
What does the 3rd aortic arch form?
Common carotid arteries
What does the left 4rd arch form?
Aortic arch
What does the right 4th arch form?
Right subclavian artery
What does the left 6th arch form?
Pulmonary trunk & ductus arteriosus
What does the right 6th arch form?
Contributes to the pulmonary trunk
Which nerve can be impinged?
Left recurrent laryngeal nerve
The trip-laminar disk forms by week 3. What are the 3 layers?
Ectoderm
Mesoderm
Endoderm
How long is the embryo by week 3?
1.5mm
What does the heart tube form from and where does it form?
Angiogenetic clusters
Mesoderm
When does cephalon-caudal and lateral folding begin?
Day 18
When does looping and folding begin?
Day 22
How does the heart end up on the left side of the body?
The two ends of the heart tube fold towards each other and slightly to the right. This pushes the apex out to the left and rotates slightly so that the right side of the heart is slightly more anterior