CVS 3 Embryology Flashcards
What are the relative pressures in the atria in utero?
- Right atrial pressure > left atrial pressure
- Oxygenated blood from the placenta arrives to the RA via the umbilical vein draining into the IVC
What germ layer does the heart and vessels arise from?
Mesoderm
How does folding of the embryo in the 4th week change the position of the caridogenic field?
Moves it caudal to the oropharyngeal membrane
What are the parts of the heart from cranial to caudal?
What do they give rise to?
- Truncus arteriosus: pulmonary trunk + aortic arch
- Bulbous cordis: RV + R+L outflow tracts
- Primitive ventricle: LV
- Primitive atrium: RA+LA
- Sinus venosus:
Describe the inflow and outflow of the initial developing heart
Inflow at caudal end
Outflow at cranial end
When is the midline heart tube formed?
3 weeks
What layer of the pericardium touches the heart?
Visceral layer
What is the transverse sinus?
Gap between arteries and veins
What is the oblique sinus?
Space within pericardial cavity behind heart
What is the adult atrium formed from?
Rough part - primitive atrium
Smooth part - Sinus venosus
Where does the SAN form from?
Sinus venosus
What forms from the 4th aortic arch?
Left - aortic arch
Right - right subclavian artery
What forms from the 3rd aortic arches?
Right - Carotid arteries
What forms from the 6th aortic arch?
Left - pulmonary artery + ductus arteriosus
Right - pulmonary artery
Why is there not a 5th aortic arch?
5th aortic arch degenerates