How Blood Moves as it Travels Through the Body

Where it is Found Blood is found within the heart of blood vessels Types of Blood Vessels: Arteries and arterioles Veins and venules Capillaries

Structure of Blood Vessels Three layers: Outer Layer – Tunica externa Made of fibrous tissue for protection Middle Layer – Tunica media Made of smooth muscle for movement Inner Layer – Tunica interna Made of squamous epithelial cells for absorption

Arteries and Arterioles Carry oxygenated blood away from the heart Contain an extra layer made of elastic tissue called the elastic laminae Helps deal with the increased blood pressure

Veins and Venules Carry deoxygenated blood back towards the heart Surrounded by skeletal muscle to help push the blood towards the heart Contains valves to prevent backflow

Capillaries Blood vessels found between arterioles and venules where gas exchange occurs Only made of tunica interna to allow for easy absorption

Blood’s Pathway Around the Body

Superior and Inferior Vena Cava

Right Atrium

Tricuspid Valve

Right Ventricle

Pulmonary Semilunar Valve

Pulmonary Trunk

Left and Right Pulmonary Arteries

Capillaries within the Alveoli of the Lungs

Left and Right Pulmonary Veins

Left Atrium

Bicuspid Valve

Left Ventricle

Aortic Semilunar Valve

Aorta

Arteries

Arterioles

Capillaries

Venules

Veins

Superior and Inferior Vena Cava