The Cardiovascular System Circulatory Routes Chapter 21

Circulatory Routes Systemic circulation is left side heart to body & back to heart Hepatic Portal circulation is capillaries of GI tract to capillaries in liver Pulmonary circulation is right-side heart to lungs & back to heart Fetal circulation is from fetal heart through umbilical cord to placenta & back

Pulmonary Circulation deoxygenated blood from the right ventricle to the air sacs of the lungs and returns oxygenated blood from the lungs to the left atrium. The pulmonary and systemic circulations differ. Blood in the pulmonary circulation is not pumped as far as in the systemic circulation, so pulmonary arteries have a larger diameter, thinner walls, and less elastic tissue. resistance to blood flow is very low meaning less pressure is needed to move blood through the lungs. normal pulmonary capillary hydrostatic pressure is lower than systemic capillary hydrostatic pressure which tends to prevent pulmonary edema.

Principle Branches of the Aorta

Systemic Circulation The systemic circulation takes oxygenated blood from the left ventricle through the aorta to all parts of the body, including some lung tissue (but does not supply the air sacs of the lungs) and returns the deoxygenated blood to the right atrium. The aorta is divided into the ascending aorta, arch of the aorta, and the descending aorta. Each section gives off arteries that branch to supply the whole body. Blood returns to the heart through the systemic veins. All the veins of the systemic circulation flow into the superior or inferior vena cava or the coronary sinus, which in turn empty into the right atrium.

Aorta and Its Superior Branches Aorta is largest artery of the body ascending aorta 2 coronary arteries supply myocardium arch of aorta -- branches to the arms & head brachiocephalic trunk branches into right common carotid and right subclavian left subclavian & left carotid arise independently thoracic aorta supplies branches to pericardium, esophagus, bronchi, diaphragm, intercostal & chest muscles, mammary gland, skin, vertebrae and spinal cord

Coronary Circulation Right & left coronary arteries branch to supply heart muscle anterior & posterior interventricular aa.

Arch of Aorta

Thoracic and Abdominal Aorta

Thoracic Aorta

Abdominal Aorta

Abdominal Aorta Pelvis and Lower Limbs

Veins of Systemic Circulation

Drainage of Head

Drainage of Limbs

Veins of thorax

Abdomen and Pelvis

Drainage of Lower Limbs

Hepatic-Portal System

Hepatic-Portal System

Fetal Circulation

Fetal Circulation