Circulatory System

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    
                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

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