CARDIOVASCULAR PHYSIOLOGY

Overview

Anatomy and Background Information Controlling Respiration Heart Rate and Cardiac Output Effects of Disease Aerobic Exercise

Gas Exchange and Transport Partial Pressure Transporting Oxygen in Blood Transporting Carbon Dioxide in Blood

Partial Pressure Body’s supply of oxygen depends upon the

concentration and pressure of oxygen in ambient air.

Concentration in ambient air:Oxygen 20.93%Nitrogen 79.04%Carbon Dioxide 0.03%

At sea level, the pressure of the above is sufficient to raise a column of mercury to a height of 760 mm

Cardiac Output - Exercise Cardiac output increases in proportion to

exercise intensity. This is due to an increase in heart rate

and stroke volume. Trained have greater exercise cardiac

output due to greater stroke volumes.

Cardiac Output - Trained vs. Untrained

Cardiac Output = Heart Rate x Stroke Volume

Untrained 5000 mL 70 bpm x 71 mL Trained 5000 mL 50 bpm x 100 mL

At Rest:

Cardiac Output = Heart Rate x Stroke Volume

Untrained 22,000 mL 195 bpm x 113 mL Trained 35,000 mL 195 bpm x 179 mL

Max. Exercise:

Adapted from McArdle, Katch, and Katch

Myocardial Infarction

Inadequate blood reaching heart muscle, causing necrosis of heart muscle

Does not go away with rest Onset usually preceded by severe

fatigue for several days Occlusion of 4-6 hours will result in

irreversible damage

What a Coronary Artery Occlusion looks like

Arrows indicate occlusions. From http://www.rjmatthewsmd.com/Definitions/myocardial_infarction.htm

AEROBIC EXERCISE

Factors That Influence Performance Maximal oxygen consumption Lactate threshold Fuel utilization Muscle fiber characteristics Exercise economy

Interval Training

Allows for a greater volume of exhaustive work to be performed.

Benefits:Teaches race paceCan improve anaerobic metabolismCan improve maximal oxygen consumptionIncreases speed

Interval Training Variables Intensity of the exercise Duration of the exercise interval Length of recovery Number of repetitions