Cardiovascular System Factors That Affect Blood Flow Factors

Cardiovascular System Factors That Affect Blood Flow

Factors That Affect Blood Flow Blood Pressure Blood Volume Blood Viscosity Resistance Disease Exercise

Blood Flow and Pressure Gradient Highest Pressure at left Ventricle--Squeezes blood to aorta and out to the body Lowest pressure is blood returning to heart at right Atrium—Squeezes to right Ventricle, to lungs to get oxygen From lungs to left atrium and back to left ventricle Cells

Blood Pressure Systole—Squeeze, contraction Diastole—Fill, “dreamy” Blood Pressure measurement is taken during systole and diastole of left ventricle The top number is systole The lower number is diastole Normal for average male is 120/80 Normal for average female is 110/70

Blood Pressure Force on vessel walls Highest as left ventricle squeezes, contracts Lowest at right atrium Pressure gradient Systole/diastole = ventricle squeeze/ventricle fill

Blood Volume About 5. 25 Liters of blood in a person Stroke Volume—Amount of blood in each beat Volume How much blood in ventricle How hard the contraction, squeeze How much resistance in vessels Cardiac Output—Amount of blood in one minute Output Stroke Volume times Heart Rate Average male— 5. 25 L/minute

Blood Viscosity is the thickness of blood It is a direct measure of the blood’s ability to flow. Measures how much friction the blood causes affect the vessels Measures how much oxygen is delivered Measures how hard the heart is pumping blood Higher viscosity increases resistance causing high blood pressure, elevated cholesterol, type-II diabetes, and obesity

Resistance Force that slows down blood flow Caused by blood as it touches vessel walls Longer vessels touch more blood Wide vessels do not touch as much blood Thick, viscous blood has more resistance—viscosity means thickness

Disease Hypertension—high blood pressure Hypertension – Plaque builds up making narrower vessels with more pressure—heart attack, stroke – Surgery can replace bad vessels Sickle Cell Anemia--Genetic disease—painful, tired Anemia- Normal red blood cell become “C” shaped Cells get stuck, block vessels and clump together Blood transfusions Exercise, fruits and veggies but no smoking, no overeating

Exercise Increases blood pressure Increases blood flow More blood to muscles and less to stomach Same blood to brain Heart beats faster and harder to get more oxygen to cells

Test 1. Which side of heart is deoxygenated? 2. Where does blood from the left ventricle go? 3. The part of the heart beat in which the ventricles fill is called _______. 4. Highest blood pressure is found ____. 5. Average female has blood pressure of _____. 6. There is about ____ of blood in a person. 7. Cardiac Output is the amount of blood per _______.

Test 1. List 3 factors that cause more resistance. 2. Viscosity means ____. 3. High Blood Pressure can cause _______. 4. Sickle Cells are a problem because they ____. 5. 4 ways to keep your heart healthy: _____. 6. Exercise increases blood ____.

Answers 1. Right 1. Thickness 2. The body 2. Heart failure, stroke 3. Diastole 3. Block blood flow, stick together 4. Left ventricle 5. 110/70 6. 5. 25 L 7. Minute 8. Viscosity, length, diameter 4. No smoking or overeating, eat fruits and veggies, exercise 5. Flow and pressure