Anatomy & Physiology
Which of the following is not true based on the cardiovascular changes at birth?
The umbilical vessels degenerate and become fibrous cords.
Rising O2 levels lead to the constriction of the ductus arteriosus.
The expansion of the lungs results in a sudden decline in resistance in the pulmonary circuit.
The fossa ovalis marks the site of the ductus arteriosus in adults.
