In: Biology
provide a detailed description of pulmonary and systemic circuit (including the heart). How is the blood circulation pathway different on a fetal pig? Why?
Mammalian heart including pig has four chamber which is two type atrium and ventricle. Heart form two circulating circuit , first one present between the heart and lungs called pulmonary circuit while another one present between heart and rest organ of body called systemic circuit. In pulmonary circulation right atrium received blood from both superior and inferior vana cava and passes in to right ventricle, right ventricle pumps blood into pulmonary circuit. After gaseous exchange in lung , the left ventricle received oxygenated blood which passes in to left ventricle. Left ventricle pump out blood into systemic circuit.
Foetal circulation is different from adult circulation because in foetus, the gaeous exchange of blood takes place on placenta in place of lungs. Umbilical artery carries deoxygenated blood to placenta from foetal heart while umbilical vein carries oxygen rich blood back to foetal heart from placenta. Foetus has two trick to adopt this type circulation. First , blood from right ventricle enter directly into aorta though ductus arteriosus than into enter into systemic circulation while in adult , blood needs to go to lungs for gaseous exchange.
Second, a opening present between right atrium and left atrium for fast foetal blood circulation called for aman ovale.