The Circulatory System Function Its main function is

The Circulatory System

Function • It’s main function is Transportation • Blood is used as a transport vehicle – transports oxygen, nutrients, cell waste (such as Carbon dioxide), hormones and antibodies vital to maintaining homeostasis to and from cells

Parts of the Circulatory System • Divided into three major parts: – The Heart – The Blood Vessels – The Blood

The Major Organ-The Heart • Heart acts as pump • The heart pumps 60 -80 beats per minute (at rest) • At REST, the heart pumps about 5 litres of blood a minute. • During EXTREME exercise it can pump 40 litres a minute.

Structure • Size of your fist • Large organ composed of – cardiac muscle--called myocardium – 4 hollow chambers – Contain valves to keep blood flowing in ONE direction

The pathway looks like a circle • The heart, the lungs, and the blood vessels work together to form the circle part of the circulatory system.

The Chambers • The heart has 4 hollow chambers • Upper chambers – atrium receives blood coming in from the veins – Left & right Atrium • Lower chambers - ventricle squeezes blood out into the arteries – Left & right ventricle

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Blood Vessels Hollow tubes that circulate your blood • Arteries • Veins • Capillaries

Arteries • • • Carry blood AWAY from the heart Heart pumps blood Main artery called the aorta Aorta divides and branches Many smaller arteries Each region of your body has system of arteries supplying it with fresh, oxygen-rich blood.

Capillaries • • • Very thin Only one cell thick Connect arteries & veins Food and oxygen released to the body cells Carbon dioxide and other waste products returned to the bloodstream

Veins • Carry blood to the heart • Receive blood from the capillaries • Transport waste-rich/ oxygen-poor blood back to the lungs and heart • Valves are located inside the veins • Allow blood to move in one direction

Blood • Carries nutrients, water, oxygen and waste products to and from your body cells.

Blood – RBCs • Red blood cells carry oxygen from the lungs to all the cells of the body. • Takes carbon dioxide and transports it back to the lungs • About 5, 000 Red Blood Cells in ONE drop of blood.

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Blood – WBCs • White blood cells protect the body from germs • Attack and destroy germs when they enter the body

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Blood – Platelets and Plasma • Platelets are blood cells that help stop bleeding • Plasma is the liquid part of the blood • About half of your blood is made of plasma • The plasma carries the blood cells throughout the body • Plasma is made in the liver.