Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
A presentation by Ms. Vriksha ~for educational purposes only~ System Circulatory System (cont’d) • • • • • The word circulation means “going around” Circulatory system – organ system Moves food and oxygen to each cell It then takes away cell wastes Like all systems, each part of the circulatory system has structures to help get the job done Blood vessels • Like roads for blood cells • Three kinds of blood vessels: 1. Arteries 2. Capillaries 3. Vein Arteries Arteries (cont’d) • Have thick, muscular walls • These walls stretch as the heart pushes blood into them • Branch many times into smaller and smaller tubes. Capillary • Smallest arteries branch to become capillaries • Smallest kind of blood vessel • Side by side, 10 capillaries would be barely as thick as one hair • Capillary walls are only one cell thick • Gases can pass through these thin walls • Oxygen and glucose move them the blood cells in capillaries to your body’s cells Capillaries (cont’d) • Gases can pass through these thin walls • Oxygen and glucose move from the blood cells in capillaries to your body’s cells • Carbon dioxide and other wastes move from cells to the blood in the capillaries Veins • Blood cells that transport blood toward the heart • Tiny veins join together to form larger veins • Unlike arteries and capillaries, veins have valves Veins (cont’d) • Valves are flaps that act like doors to keep blood flowing in only in one direction • Valves open to let blood flow to the heart • Valves close if the blood starts flowing away form the heart Arteries vs Veins 1) 2) 3) 4) 5) 6) Arteries Carry blood away from the heart always. Have thick muscular walls Have a pulse Deep under the skin Have no valves Arteries branch at their ends, into tiny arterioles those then join capillaries Veins 1. Carry blood to the heart. 2. Have thin walls 3. Do not have a pulse 4. Near surface of the skin 5. Have valves to stop backflow of blood. 6. Veins branch at their beginnings into tiny venules which join capillaries. Blood vessels (cont’d) • Huge numbers of blood vessels form a network throughout your body • If all blood vessels were laid end-to-end, they would stretch around Earth more than twice