Age-related changes in the heart’s electrical conduction system such as fibrosis and loss of specialized cells and fibers in the SA node and fibrosis of AV node and left anterior fascicle contribute to the development of (choose all that apply): a. Normal heart rate at rest b. Increase in atrial ectopy (irregular, rapid heartbeats) c. Increase in episodes of bradycardia (slow heart rate) d. Increased incidence of heart block.

2) Insert increase or decrease into each of the sentences below which are concerned with blood pressure regulatory mechanisms that result in a decrease in blood pressure. • A decrease in blood pressure causes a(n) in nerve impulses from the baroreceptors to the Cardiovascular Control Centre ● • This increases the sympathetic nervous system input to the heart resulting in a(n) in heart rate. Sympathetic nervous system input to the blood vessels s causing vasoconstriction of both the arterial and venous side of the circulation. • The blood pressure is therefore normal level. ed to a

4. A change in pulse pressure can be seen in a variety of medical conditions. What would you expect to happen to the pulse pressure in the following examples? a. In atherosclerosis there is a hardening of the arterial walls. Explain b. A damaged aortic semilunar valve does not seal properly and allows blood to flow back into the ventricle during diastole. Explain EXTENSIONS 1. Exercise for varying lengths of time and compare the blood pressure and pulse readings taken after each exercise period. You can run around the building, and attach the cuff upon returning. 2. Perform different types of exercise for the same amount of time and compare the blood pressure and pulse readings taken after each type of exercise. 3. Measure blood pressure 5, 10, and 15 minutes after stopping exercise, and compare readings as your heart returns to resting heart rate. 4. Measure blood pressure while lifting a weight with the opposite arm.

4. Pathophysiology of cardiac arrhythmia?