1. The Cardiovascular System

8. How do bruises form? Capillaries have walls that are only one cell layer thick - so they are very fragile If you get hit on your arm with a baseball… o The capillaries get ruptured by the impact o The blood contained within them gets released into the spaces between tissues o This produces the discoloration and possible swelling known as a bruise

9. Blood Pressure Diastole: When atria are relaxed (i.e. filled with blood) Systole: Atria push blood into ventricles Ventricles contract and push blood into arteries When AV valves shut – LUBB Ventricles relax – DUBB Written as: DIASTOLIC pressure (mm Hg) SYSTOLIC pressure (mm Hg)

10. How do we take Blood Pressure? Need to use a stethoscope Normal systolic should be 120 mm Hg Normal diastole should be 80 mm Hg To measure: Tighten the cuff…as soon as you release you should hear a lubb sound – measure pressure (systolic – should be 120 mm Hg) Then deflate until sound disappears – check pressure (diastole – should be 80mm Hg) Sphygmomanometer

11. BLOOD Made up of Role is to