Coronary Circulation Chapter 12

Blood Supply to the Heart Muscle The heart muscle (myocardium) must be fed with blood

Great Vessels Vessels carry blood to and from the heart. Consist of: Superior and Inferior Vena Cave Pulmonary arteries (2) Pulmonary veins (4) Aorta

Great Vessels Pulmonary artery Pulmonary veins Carries unoxygenated blood from the RV to the lungs Pulmonary veins Carry oxygenated blood from the lungs to the LA

Coronary Arteries Blood supply for the heart comes from two main arteries Left coronary artery Right coronary artery

Types of Blood Vessels Arteries Veins Carry oxygenated blood away from the heart to the tissues (except for the pulmonary artery) Arterioles: small arteries – carry blood toward capillaries Capillaries: about 1 cell thick – exchange of nutrients and gases Carry unoxygenated blood from the body back to the heart (except for the pulmonary veins) Venuoles: small veins connected to capillaries – carry blood away from capillaries

How veins and arteries are constructed 3 structures common to both Tunica Intima - inner layer endothelial cells in contact with the blood Tunica Media - middle layer thickest layer more elastic made of smooth muscle Tunica Externa/Adventia - outer layer made of connective tissue, collagenous fiber. The toughest layer

FYI...... Arterial system is under high pressure 120-? Mmhg Venous system is under relatively low pressure 4-20mmhg

PERIPHERAL CIRCULATION Movement of blood through the body PERIPHERAL CIRCULATION

Anatomy of Peripheral Circulation All the blood vessels of the body form a network that carries blood to and from the heart to deliver oxygen and nutrients, and return carbon dioxide and waste products

Flow of blood through the body Veins have a unique structure equipped with a one-way valve to prevent the backflow of blood Precapillary sphincters – guard the capillaries – determine which capillary the blood will flow

Blood flow to and from the liver HEPATIC PORTAL

Hepatic Portal Circulation Veins from the spleen, stomach, pancreas, gallbladder, and intestines send their blood through the hepatic portal vein into the liver. route of blood flow through the liver

Blood goes through a capillary bed in the liver Hepatic Portal Blood goes through a capillary bed in the liver helps remove excess glucose and store it as glycogen also remove and detoxify various poisonous substances that may be present in the blood.