EXERCISE PHYSIOLOGY

The Circulatory System The heart, arteries and veins make up the circulatory system. There are 2 different circulations of blood within the body: Pulmonary – circulation of blood between heart and lungs. Takes de-oxygenated blood to lungs to refuel with oxygen. Systemic – circulation of blood between the heart and body. Ensures oxygenated blood is distributed to muscles of the body.

3 types of blood vessels in the body: Arteries – thick-walled vessels that carry oxygenated blood away from the heart at high pressure. Capillaries – thin-walled vessels that oxygen and nutrients can move through to cells, and carbon dioxide can move into, from cells. Veins – thin-walled vessels which carry deoxygenated blood towards the heart at low pressure. Veins have valves to prevent the backflow of blood.

Circulatory System

Blood performs 4 key functions: Transportation of materials such as; gases (O 2 & CO 2 ), nutrients, hormones and wastes. Temperature control. Transport heat to the surface of the body. Fluid balance to keep tissues hydrated & nutrient concentrations within the correct balance. Protection against infection.

The Heart Pumps blood around body. 4 chambers: upper 2 chambers called atria, bottom 2 are called ventricles. Blood leaves the heart from the aorta; from there it goes to muscles and organs where they use the oxygen carried in the blood. Blood returns to heart and lungs to be re- oxygenated.

The Heart

The HeartIs about the size of your fist

Animated Heart

The Heart During exercise muscles require more oxygen. Therefore the heart pumps faster by beating more times per minute and pumps more blood with each stroke. The heart beats with enough force to push blood around the entire body.

The Heart Heart Rate (HR) = Number of heart beats per minute. Stroke Volume (SV) = The amount of blood ejected by the heart per beat. Measured in litres (L). Cardiac Output (Q) = The amount of blood ejected by the heart per minute. Measured in litres/per minute (L/min). Q = SV x HR QUESTION: Calculate the cardiac output for an athlete with a SV of 85ml and HR of 155 b/min ?

The Heart Answer:  Q = SV x HR  = (85/1000) x 155  = 13.2L/min  NOTE: SV had to be converted from ml to L.

Respiratory System The lungs, mouth, throat and nose make up the respiratory system. Its major function is to bring oxygen O 2 into the body and remove carbon dioxide CO 2. Oxygen is inhaled down through the bronchi and into the alveoli of the lungs, where it gets picked up by the blood. Carbon dioxide and other waste is transferred from the blood to the air in the lungs and exhaled out of the body.

Respiratory System

During exercise breathing becomes faster and deeper, allowing more oxygen to be inhaled and transferred to working muscles via the circulatory system. During exercise both the circulatory and respiratory systems need to work harder to cope with the extra demand by the working muscles for O 2. Because of the close relationship they both play in this process we often refer to them as a single system.

The Cardio respiratory System or The Cardio vascular System