7. Types of Blood vessels Vessel Structure Function Diagram Artery Thick elastic walls Small circumference Transports blood AWAY from the heart Vein Thin, less elastic walls with valves Large circumference Transports blood TOWARDS the heart Capillary Very thin wall Smallest circumference Materials are exchanged between the blood and the body
9. Capillaries Walls of blood vessels are made up of cells called endothelial cells . The thin layer of endothelial cells allows diffusion to occur more rapidly.
10. Capillaries Red blood cells travel through the capillary in single file. Blood velocity is the slowest in capillaries
14. What is in blood? -red blood cells (erythrocyte) carry oxygen -white blood cells (leucocytes) part of the immune system -platelets stop bleeding by clotting blood -plasma contains nutrients like amino acids and glucose -water
19. Comparing atria and ventricles Atria Ventricles Location Upper half of heart Lower half of heart Thick-ness Thinner walls (pumps blood to ventricles below) Thicker walls (pumps blood to lungs or to rest of the body)
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21. The SA node and the AV node SA node = sinoatrial node AV node = atrioventricular node
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