There are many reasons kids' hair might fall out abnormally or excessively. Tinea capitis. The most common cause of hair loss in children is an infection known as tinea capitis. Tinea capitis is a type of ringworm that attacks the hair and causes scaly, ring-like lesions to form.
The right atrium pumps blood through the right atrioventricular (tricuspid) valve to the right ventricle. From the right ventricle, blood flows through the pulmonary valve to the lungs via the pulmonary arteries (deoxygenated blood).In the lungs the blood becomes more red in color as it is oxygenated.Blood returns to the heart via the pulmonary veins (oxygenated blood) to the left atrium.The left atrium pumps blood through the left atrioventricular (bicuspid or mitral) valve to the left ventricle.n the lungs the blood becomes more red in color as it is oxygenated. Blood returns to the heart via the pulmonary veins (oxygenated blood) to the left atrium. The left atrium pumps blood through the left atrioventricular (bicuspid or mitral) valve to the left ventricle.
As the ventricles begin to contract, the pulmonic and aortic valves are forced open and blood is pumped out of the ventricles through the open valves into the pulmonary artery toward the lungs, the aorta, and the body.he four heart valves make sure that blood always flows freely in a forward direction and that there is no backward leakage. Blood flows from your right and left atria into your ventricles through the open mitral and tricuspid valves. When the ventricles are full, the mitral and tricuspid valves shut.