BLOOD PRESSURE Unit 3: Transportation and Respiration
Blood Pressure The force of your blood pushing on the walls of your arteries.
How is Blood Pressure Measured? Measured at an artery in the arm and recorded in millimetres of mercury, or mm Hg. Systolic pressure is presented over diastolic pressure. Ex: A healthy young person has a blood pressure reading of about 120 mm Hg over 80mm Hg, or 120/80. When the heart rate increases, ventricles must push a greater volume of blood per unit of time, so pressure within the arterial system also increases.
Blood Pressure Normal is 120/80 (systolic/diastolic) Systolic The top number. Heart muscles contract Diastolic The bottom number. When heart is resting, filling with blood
Blood Pressure Hypertension (high blood pressure) Blood pressure remains above normal throughout the heartbeat cycles
Sphygmomanometer
What might cause your blood pressure to increase?
Exercise Heart rate and blood pressure will increase temporarily in response to an increased demand for oxygen in the body s tissues. Example: running.
Hypertension Hypertension (chronically elevated blood pressure) is associated with heart disease. Conditions that either increase the volume of blood or reduce the elasticity of the arteries can produce hypertension. Causes thickening of the ventricles of the heart because it has to pump harder.
Aging As people age, their blood pressure tends to increase. Blood vessels become less elastic, making blood circulation less efficient. Reason why older people tend to feel colder.
Diet High salt diet causes blood to retain more water - increases the volume of blood to be pumped by the heart.
Diet Diet high in fats and cholesterol causes arteries to become clogged, reducing their elasticity and narrowing the vessels.
Diet Artificial stimulants (i.e. caffeine, nicotine) imitate the effects of noradrenaline causing a temporary increase in heart rate.
Lifestyle Heredity, age, lack of exercise, smoking, and obesity can also lead to hypertension.
Treatment for Hypertension Beta Blockers Medications that lower the heart rate, the amount of blood the heart pumps, and the force of the heartbeat. Diuretics Cause kidneys to remove more sodium and water from the body (urinate more often). Helps to relax blood vessels, lowering BP.
Atherosclerosis Atherosclerosis -narrowing of the arteries from the deposit of cholesterol-rich plaques on the innermost layer of the artery wall. Symptoms: Atherosclerosis in arteries to the heart (coronary artery disease) can cause angina (chest pain), shortness of breath, or even a heart attack. Atherosclerosis of the arteries to the brain (carotid artery disease) can cause strokes.
Treatments More exercise, better diet, medicines (aspirin) Angioplasty cardiologist inserts a fine plastic tube into a clogged artery, a tiny balloon is pushed out from the tip forcing the vessel to open.
Treatments Coronary bypass removing a segment of healthy blood vessel from another part of the body and using it to create a new pathway around a blockage in a blood vessel near the heart. double or triple refers to the number of vessels containing blockages that must be bypassed.
Prevention of Hypertension and Atherosclerosis Diet low in saturated fat and cholesterol, high in fruits and vegetables reduces the amount of plaque that can build up in the arteries. Eating small amounts of walnuts or almonds. Exercise. Not smoking.
Questions 1. What is the natural pacemaker of the heart? What does it do? 2. What is the difference between systole and diastole? 3. What hormones affect the heartbeat cycle? Which ones slow it down and which ones speed it up? 4. What is blood pressure? What is a healthy blood pressure? 5. What is hypertension? 6. What are the causes of hypertension? 7. What are the treatments for hypertension? 8. What is atherosclerosis? 9. What are the treatments for atherosclerosis? 10. How would you prevent any heart disease?