Circulatory System

Organs in the circulatory system are: • Blood • Heart • Blood vessels

The function is to transport products from the digestive and respiratory systems to the body’s cells..

The Heart •  The circulatory system must provide

essential nutrients and other materials that your cells need.

•  The heart pushes blood through the circulatory system

•  The heart functions as two pumps- – One pump is on the right and it pumps

blood to the lungs. – One pump is on the left and it pumps

blood to the rest of the body.

Four Chambers of the Heart

Right atrium Right ventricle Left atrium Left ventricle

Entryway into the Heart

Two of the four entryways come from the Superior Vena Cava from the upper body, and the Inferior Vena Cava from the lower body. These lead to the right atrium. Blood coming into the right atrium is poor in oxygen

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From the right atrium… At this point, the blood passes

through the tricuspid valve and moves into the right ventricle. From here it exits by means of the pulmonary artery and moves to the lungs

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What happens at the lungs? At the lungs, the blood drops off carbon

dioxide and picks up oxygen and then has to travel back to the heart to be pumped to the body’s cells. It reenters the heart through the pulmonary veins and goes into the left atrium. It then moves through the mitral valve and into the left ventricle and then exits the heart and is carried to various parts of the body through the aorta (it’s the largest blood vessel in the body!!!)

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Blood Vessels •  There are three types of blood vessels:

– Arteries, which carry blood away from the heart.

– Veins, which carry blood back to the heart.

– Capillaries, which connect arteries with veins. • Veins and arteries branch off into very

narrow blood vessels called capillaries.

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Blood

•  Blood is a tissue that consist of 4 components: – Plasma- liquid portion of blood (60%) – Red Blood Cells- Carries oxygen – White Blood Cells- fights infections and

diseases. – Platelets- help clot blood.

Four Blood Types Each red blood cell has special structures on them

called antigens

Blood Pressure • Blood Pressure- the force produced when

the heart contracts travels through the blood and exerts pressure on the blood vessels. • Blood pressure is caused by the force

with which the ventricles contract.