NEET Class neet Answered
Myocardial infarction: The coronary arteries take oxygen rich blood specifically to your heart muscle. When these arteries become blocked or narrowed due to a buildup of plaque, the blood flow to your heart can decrease significantly or stop completely. This can cause a heart attack.
Patent foramen ovale (PFO): This occurs when the foramen ovale fails to close. The foramen ovale is a hole in the wall between the left and right atria of every human fetus. This hole allows blood to bypass the fetal lungs, which cannot work until they are exposed to air. When a newborn enters the world and takes its first breath, the foramen ovale closes, and within a few months it has sealed completely in about 75 percent of us. When it remains open, it is called a patent foramen ovale, patent meaning open. For the vast majority of the millions of people with a PFO, it is not a problem, even though blood is leaking from the right atrium to the left. This can cause mixing of pure and impure blood.
Patent ductus arteriosus (PDA): It is a persistent opening between the two major blood vessels leading from the heart. The opening, called the ductus arteriosus, is a normal part of a baby's circulatory system before birth that usually closes shortly after birth. If it remains open, however, it's called a patent ductus arteriosus. This can cause blood to mix.
Atherosclerosis is a disease in which plaque builds up inside your arteries restricting the bloof flow.
Ventricular septal defect (VSD) is a hole in the heart. It is a common heart defect present at birth (congenital). The hole (defect) occurs in the wall (septum) that separates the heart's lower chambers (ventricles) and allows blood to pass from the left to the right side of the heart. The oxygen-rich blood then gets pumped back to the lungs instead of out to the body, causing the heart to work harder.
Thus, of the above defects, patent foramen ovale, patent ductus arteriosus and ventricular septal defect may result in mixing of pure and impure blood.
So, the correct answer is option (3) Three.