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Primary Functions 2

The heart is a muscular organ that is responsible for pumping blood to all parts of the body the CIRCULATORY SYSTEM

There are two Circulatory Pathways: 1.Systemic circulation, 2.Pulmonary circulation. There are two Circulatory Pathways: 1.Systemic circulation, 2.Pulmonary circulation. 4

Pulmonary circulation involve the flow of blood poor in Oxygen from the right chambers into the lungs. Right Atrium –Receives O 2 -poor blood from body via IVC, SVC Right Ventricle –Receives O 2 -poor blood from right atrium through tricuspid valve –Pumps blood to aorta 5

Systemic Circulation involve the flow of blood rich in Oxygen from the left heart chambers to other parts of the body Left Atrium –Receives O 2 -rich blood from Pulmonary Veins Left Ventricle –Receives blood from Left Atrium via bicuspid valve –Pumps blood into aorta via Aortic Semilunar Valve to body 6

Systemic ( top part of body) Systemic ( top part of body) Systemic (lower part of body) Systemic (lower part of body) Pulmonary ( heart to lungs) Pulmonary ( heart to lungs) 7

Arteries are blood vessels that carry blood, rich in oxygen, from the heart to other parts of the body. The large arteries have thick walls of elastic-like tissue that enables them to withstand the blood pressure created by the heart’s beating Arteries are blood vessels that carry blood, rich in oxygen, from the heart to other parts of the body. The large arteries have thick walls of elastic-like tissue that enables them to withstand the blood pressure created by the heart’s beating 8

Capillaries are tiny, thin-walled blood vessels that connect arteries to veins and are located in all body tissues. Capillaries are so small in diameter that blood cells pass through in a single file. 9

CAPILLARIES ALLOW FOR: nutrients, oxygen, and water to diffuse out of blood to the tissues. Waste products, like Carbon dioxide, diffuse from the tissues into the blood. 10

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Comparative View between Arteries and Veins Click to Play 12

Arteries (aa.)Veins (vv.) Arteries (aa.)Veins (vv.) Direction of flow Blood Away from Heart Blood to Heart PressureHigherLower WallsTHICKER: Tunica media thicker than tunica externa THINNER: Tunica externa thicker than tunica media LumenSmallerLarger 13

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