briefly differentiate the cardiovascular between fetus, newborn, and adult.

The placenta is a mechanical and physiological connection between mother and fetal tissue. The umbilical cord consists of blood vessels and circulates blood between mother and fetus. The fetus has shunts, which bypasses the lungs and liver for proper circulation. The human heart is myogenic. It is a type of heart in which the impulse is generated in or by muscles. Here it's tissue or node which is a specialized cardiac muscle. SA node, AV node, Bundle of Hiss, and Purkinje fibers are involved in the generation of impulse.

•During fetal life, the placenta is a mechanical and physiological connection between mother and fetal tissue. The umbilical cord consists of blood vessels and circulates blood between mother and fetus. The fetus has shunts, which bypasses the lungs and liver for proper circulation. There are five structures involved in fetal circulation. These are the placenta, umbilical cord, three shunts foramen ovale, ductus arteriosus, and ductus venosus. The placenta provides life support to the fetus from the mother. Oxygen and nutrients are sent to the fetus across the placenta. The umbilical cord consists of many blood vessels involved in providing all needed nutrition and oxygen to the fetus from the mother's body. Foramen ovale is the shunt that bypasses the lungs, and the blood from the right atrium is sent to the left atrium directly through this opening. The ductus arteriosus is the shunt that moves the blood from the pulmonary artery to the aorta for circulation. Ductus venosus is the shunt that bypasses the liver. This shunt allows highly oxygenated blood from the liver to the inferior vena cava and then to the right atrium of the heart.

•After birth, the newborn takes the first breath, when the air rushes in the pulmonary resistance inside the lungs decreases, and blood flow through the placenta stops. At birth the umbilical cord is clamped off and the newborn does not receive any oxygen and nutrients from the mother after birth and after birth, the newborn takes the first breath, when the air rushes in the pulmonary resistance inside the lungs decreases, the lungs start to expand and blood flow through the placenta stops. The shunts like the ductus arteriosus and the foramen ovale both close.

•In adults the interventricular septum of the heart makes a complete separation of the oxygenated and deoxygenated blood. The deoxygenated blood from the right ventricles must be pumped to the lungs. The pulmonary artery takes the deoxygenated blood to the lungs for oxygenation. The Oxygenated blood from the left ventricle must be pumped to all the organs of the body via the systemic arch or the aorta. This double circulation is divided into Systemic circulation or greater circulation and pulmonary circulation or smaller circulation. Systemic circulation means the circulation of blood to and from the body parts. Pulmonary circulation is to and from the lungs. i.e the blood is going to the lungs and coming back from the lungs.