Circulatory System
Textbook pages ____ – ______
(Add beautiful coloured illustrations within carefully drawn rectangles.)
A. Heart
      1. a pump (4 L of blood / minute)
      2. a muscle (size of your fist)
      3. four chambers
            a. two atrium chambers = atria
                  i. right atrium (from body into heart)
                  ii. left atrium (from lungs into heart)
            b. two ventricle chambers
                  i. left ventricle (from heart to body)
                  ii. right ventricle (from heart to lungs)
      4. valves (allow blood to flow in only one direction)
B. Blood Vessels
      100 000 km in length (2.5 x around the earth’s equator)
      1. Arteries
            a. blood from the heart
            b. bright red and full of oxygen
            c. under pressure so need thick walls
            d. only one carries deoxygenated blood
               from heart to lungs
      2. Capillaries
            a. tiny interchanges
            b. oxygen, nutrients, glucose goes
               to the fluid around cell tissues
            c. carbon dioxide and other wastes
               leave the cells and go into capillaries
      3. Veins
            b. blood to the heart
            c. no longer full of oxygen
            d. thicker and darker in colour
            e. not under pressure so thinner walls
            f. valves prevent backflow
            g. only one carries oxygenated blood from
               lungs to left side of heart
C. Blood Components
      1. body contains about 5 L of blood
      2. 55% is plasma  Â
            a. clear and yellowish
            b. contains proteins, minerals, dissolved salts
      3. 45% is…
            a. red blood cells
                  i. 2 million produced per second
                  ii. made in bone marrow, liver, spleen
                  iii. carry oxygen and carbon dioxide in…
                  iv. hemoglobin = protein molecules
            b. white blood cells
                  i. 5000 – 11000 per drop of blood
                  ii. bigger than red blood cells
                  iii. fight infection & prevent cancer growth
            c. platelets
                  i. stop bleeding by creating clots
                 ii. 200,000 – 400,000 per drop of blood