1. Michael Masher Assessment Activity 2 – That’s What Friends Are For! Unit 2: The Physiology of Fitness P2 – Describe the Cardiovascular and Respiratory Systems Responses to Acute Exercise

2. Cardiovascular Heart Rate Anticipatory Response: Nerves that directly supply your heart and chemicals in your blood can rapidly alter your heart rate, before the start of the exercise your heart rate usually increases above resting levels. Activity Response: At the start or just before the exercise, nerve centres in your brain detect cardiovascular activity. This results in adjustments that increase the rate and pumping strength of your heart. At the same time the regional blood flow is altered in proportion to the intensity of the activity undertaken. Increased Blood Pressure: Blood pressure is the pressure of blood against the walls of your arteries and results from 2 forces. During exercise, despite both cardiac output and blood pressure increases , these mechanisms act to restrict the blood pressure rise and eventually bring it down. Vasodilation & Vasoconstriction: The primary function of vasodilation is to increase blood flow in the body to tissues that need it most. Vasoconstriction is the narrowing of the blood vessels resulting from contracting of the muscular wall of the vessels, which is the opposite of vasodilation.

3. Respiratory Increase in Breathing Rate (Neural and Chemical Control): Exercise results in an increase in the rate and depth of breathing. During exercise your muscles demand more oxygen and the corresponding increase in carbon dioxide production stimulates faster and deeper breathing. A minor rise in breathing rate prior to exercise is known as an anticipatory rise. After several minutes of aerobic exercise, breathing continues to rise, though at a slower rate, and it levels off if the exercise intensity remains constant. Neural involves the brain and nervous system, for example, you are affecting your rate of breathing by use of your brain. Chemical is of course involuntary effect on breathing of a chemical entering the system, such as an anesthetic which slows the breathing and renders you unconscious. It would imply that the brain is not able to override a chemical control or influence. Increased Tidal Volume: Tidal volume is the volume of air you breathe in a single breath. Exercise causes an increase in tidal volume because your requirements for oxygen go up. This increase is measured in different ways depending on when it occurs during your exercise. An increase in tidal volume is necessary to effectively meet your body's increased oxygen requirements, as an increase in your rate of respiration alone is not sufficient. Tidal volume is approximately 500 ml of air per breath. However, changes in air requirements, such as those that occur during exercise, and changes in your lungs' ability to expand and contract.