CARDIOVASCULAR SYSTEM SC.912.L Describe the factors affecting blood flow through the cardiovascular system.

BLOOD PRESSURE IS A FORCE THAT MOVES BLOOD WITHIN THE VESSELS OF THE CARDIOVASCULAR SYSTEMS. WHAT IS THE MAJOR CAUSE OF BLOOD PRESSURE? A. amount of cholesterol in the blood B. stress that movement and exercise puts on heart muscle C. contraction of the ventricles in the heart D. removal of oxygen and nutrients from the blood

WHILE ATTENDING A COMMUNITY HEALTH FAIR, SUSAN FINDS OUT THAT SHE HAS BORDERLINE HYPERTENSION, OR HIGH BLOOD PRESSURE. WHAT LIFESTYLE CHANGES WOULD HELP TO LOWER BLOOD PRESSURE WITHOUT TAKING PRESCRIPTION MEDICATIONS? A. Adding more fried foods to the diet will provide the essential fats that the body needs for vessel elasticity. B. Drinking less water and other fluids will increase the blood viscosity or thickness so that the heart works less. C. Moderate exercise and relaxation techniques will reduce emotional stress that can be a factor in hypertension. D. The person should stop their training for a half marathon since demanding exercise elevates the heart rate.

CARDIOVASCULAR SYSTEM Blood full of oxygen flows from the heart through  arteries of decreasing size  capillaries deliver oxygen to cells  veins return oxygen-poor blood to the heart and lungs

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CARDIOVASCULAR SYSTEM Blood pressure - heart ventricle contractions create a force, or blood pressure, on arteries.  Hypertension – high blood pressure – overworks the heart and puts stress on blood vessels  Very low blood pressure – your cells do not get enough oxygen

CONTROL OF BLOOD FLOW Blood flow is determined by:  diameter of blood vessels  the larger the vessel, the faster the flow  blood vessels constrict (reduce diameter) during smoking  blood pressure  the greater the pressure, the faster the flow  blood viscosity (“thickness”)  thin blood flows faster than thick blood

CONTROL OF BLOOD FLOW Blood flow is determined by:  resistance  narrowed or blocked vessels slow down blood flow  circulated blood volume per minute decreases  key factor in arteriosclerosis – arteries have plaque (deposits of cholesterol, calcium, and fat) present

CARDIOVASCULAR HEALTH Potentially Beneficial Choices Healthy diet with a variety of fruits, vegetables, and whole grains plus moderate amounts of other carbohydrates and protein Regular exercise Don’t smoke or quit smoking Maintain healthy weight Manage stress Potentially Harmful Choices Diet high in fat, cholesterol, and salt (linked to hypertension) Inactivity Smoking Overweight or obese, especially in abdomen area Excess stress