circulatory system n.
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Circulatory system

Circulatory system

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Circulatory system

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  1. Circulatory system

  2. What are we going to learn ? • Heart • Blood circulation • Blood vessels • Blood • Blood groups

  3. Acts like a pump of the circulatory system supplying blood to the whole body Located between the lungs a little to the left; size roughly equal to a fist Made up of muscle with a dual protective layer Two internal sections unconnected to each other Left section contains Oxygen-rich blood received from the lungs Right section contains Oxygen-poor blood to be sent to lungs Each section has two chambers Upper chamber called Atrium; Lower chamber called as Ventricle Atrium and ventricle connected to each other by a one-way valve Heart

  4. Heart Internal structure Aorta (carries blood to body) Superior vena cava (carries blood to heart) Left pulmonary arteries (carry blood to lung) Right pulmonary veins (carry blood from lungs) Left atrium Pulmonary artery valve Aorta valve Right atrium Mitral valve Tricuspid valve Left ventricle Right ventricle Pericardium Inferior vena cava (carries blood to heart)

  5. Oxygen-rich blood from the lungs Oxygen-poor blood from all over the body Both valves close so that blood cannot go back to atria. Ventricles contract and blood goes out to lungs through pulmonary arteries and to the rest of the body through the aorta. Atria then expand and the cycle starts again. Atria contract, both valves open and blood enters ventricles Both atria expand and the blood enters right atrium through vena cava and left atrium through pulmonary veins 1 2 3 How does the heart function?

  6. Heart beats • Heart beats occur due to the rhythmic expansion-contraction of the heart muscles. • Normally they range between 60 to 80 per minute. • In other words the heart expands and contracts almost one hundred thousand times day !

  7. Lungs Blood circulation • This is the process of supply of blood to all the limbs of the body and its return to the heart. • Two types • Pulmonary circulation: Oxygen-poor blood travels from the heart to the lungs and Oxygen-rich blood travels back • Systemic circulation: Oxygen-rich blood travels from the heart to the all the limbs of the body and Oxygen-poor blood travels back Cells in the body

  8. Blood circulation video

  9. Blood vessels • Blood circulates through blood vessels • Network of vessels spread throughout the body • Circulation only in one direction • Three types • Arteries • Veins • Capillaries

  10. Walls of arteries are made of three layers of muscle. These thick walls contract and push blood forward Arteries • Carry blood from the heart to various limbs • No valves • Blood flows under pressure (100mm of Hg) • Other than pulmonary arteries all arteries carry Oxygen-rich blood

  11. Valves permit flow only in one direction Veins • Except for pulmonary veins all other veins carry Oxygen-poor blood from various limbs to the heart • Walls are thin • Valves stop blood from flowing in reverse direction • Blood flows under low pressure (2 mm of Hg)

  12. Capillary network Veins Artery Cells Capillaries • Consist of a network of microscopic vessels joining arteries with veins • Extremely thin walls • Capillaries permit exchange of nutrients, gases etc. in the blood with the cells

  13. Plasma Red blood cells White blood cells Blood Oxygen • Platelets Carbon dioxide Unwanted itemsAmmonia, Urea Nutrients (Glucose, Amino acids) Hormones Constituents of blood - 1

  14. Plasma 54.3% White blood cells and platelets 0.7% White blood cells Red blood cells Red blood cells 45% Platelets Plasma Constituents of blood - 2 • Plasma • Light yellow colour • Alkaline • 90% water, 7% proteins, 3% non-organic matter • Blood cells • Red blood cells • White blood cells • Platelets

  15. Red blood cells • Circular shape, No nucleus, concave on both sides • Function: Supply Oxygen to body cells • Hemoglobin in the red blood cells acts as the transport of Oxygen • 1 cubic mm contains 500 to 600 thousand red blood cells

  16. White blood cells • Colourless, amoeba-like cells with nucleus • Function: Protect body from bacteria • 1 cubic mm contains 5000 to 10000 white blood cells

  17. Platelets • Small, irregular shape • Function: Help in coagulation of blood • After a wound platelets create a network of fibrin strings • Red blood cells are trapped in the network and form a scab on the wound • 1 cubic mm = 150 to 400 thousand platelets

  18. Blood groups • Blood is grouped into 4 categories based on proteins in it • A, B, O, AB • Sub-groups Rh+ and Rh- in each group • Before donating blood the blood groups have to be matched as under

  19. The end