Learning Objectives; 1. Identify the key features of the cardiovascular system. 2. Describe the function of the cardiovascular system.

Learning Objectives; 1. Identify the key features of the cardiovascular system. 2. Describe the function of the cardiovascular system.

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The Circulatory System The circulatory system is also known as the cardiovascular system. It consists of 1. Blood 2. Blood Vessels 3. The Heart The three main types of blood vessels are arteries, veins and capillaries.

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Bicuspid valve Semi-lunar valve Semi-lunar valve

Aorta Vena Cava Pulmonary Artery (to lungs) Pulmonary Vein (from lungs) Semi-lunar Valve RA LA Semi-lunar Valve Tricuspid Valve RV LV Bicuspid Valve Septum

Blood Vessels Arteries A = Away Non-elastic fibres Muscle + elastic fibres Non-elastic fibres Lumen Muscle + elastic fibres Arteries carry blood away from the heart and have a thick, elastic, muscular wall. They stretch as blood is pumped in and the muscle wall contracts to force blood along. Veins In = In Non-elastic fibres Muscle + elastic fibres Lumen Veins have a relatively thinner and less muscular wall than arteries. The blood is under a lower pressure than in the arteries. Capillaries Capillary walls are one cell thick. Exchange of nutrients and respiratory gases occurs across their surface.

Major Blood Vessels Aorta Carries oxygenated blood from the left ventricle to the body. Pulmonary artery Carries deoxygenated blood from the right ventricle to the lungs. Vena Cava Carries deoxygenated blood from the body to the right atrium. Pulmonary vein Carries oxygenated blood from the lungs to the left atrium.

What does Blood do? Blood does the job of a non-stop courier service - it collects chemicals from one part of the body and delivers them to other parts, for use or disposal. What is Blood made of? If blood is spun in a centrifuge it will separate into 4 parts Blood spinning in a centrifuge. White blood cells help to fight infection. Plasma is a straw-coloured liquid. It is mostly water with dissolved nutrients, salts, hormones and proteins. Platelets are cell fragments. Red blood cells make up about 45% of the total volume of the blood

Red Blood Cells These have no nucleus and are very flexible so they can pass through the extremely tiny capillaries of the body. Function Their main role is to: A. Collect and carry oxygen to all the cells of the body so they can create energy. B. In order to do this, red blood cells contain Haemoglobin, which combines with oxygen to become Oxyhaemoglobin.

Why do blood vessels change during exercise? When you exercise blood is redistributed to muscles which need oxygen this is called vascular shunt How does this happen? Muscles 1. Arteries widen to stop blood pressure getting too high... 2. Blood that usually goes to organs like gut and liver is shunted to the muscles.. 3. By blood vessels in the muscles widening (vasodilation) to let in more blood OR 4. By blood vessels in the inactive organs narrowing (vasconstriction) to restrict the amount of blood that can flow in.

How Blood is Pumped around the Body Blood flows around the body in a figure of eight circuit, passing through the heart twice on each circuit. Blood travels away from the heart through arteries (A). Blood returns to the heart through veins (V). There are 2 separate loops to the circuit: The top loop (Pulmonary circulation) carries blood from the heart to the lungs and back. The bottom loop (systemic circulation) carries blood from the heart to all over the body and back. Lungs (A) (V) Heart Body (A) (V)

Blood Flow around the Body Top Loop Pulmonary circulation 1. Blood leaves the right side of the heart via the pulmonary artery and goes to the lungs where it is oxygenated. Lungs Pulmonary artery Pulmonary vein Heart 2. It then travels back to the left side of the heart via the pulmonary vein. Body

Blood Flow around the Body - Bottom Loop Systemic circulation Vena Cava Lungs 3. The left side of the heart then pumps the oxygenated blood around the rest of the body for use, via the aorta. Aorta 4. Once the oxygen has been used, the blood becomes deoxygenated and returns to the right side of the heart via the vena cava. Heart Body

Definitions of Heart Function There are three ways to measure heart performance in sport and exercise: Heart Rate Stroke Volume Cardiac Output Heart Rate The number of times the heart beats per minute. Stroke Volume The output of blood from the heart in one beat. 64 beats per minute is a typical result for a fit person at rest.

Cardiac Output Cardiac output is the total output of blood from the heart in one minute. It is calculated using the formula Cardiac Output = Stroke Volume x Heart Rate

How does the Circulatory System Contribute to Performance in Sport? The circulatory system is the body s Delivery service for oxygen, glucose & water. Waste disposal unit for carbon dioxide. Temperature control system together with the skin. As a result, the circulatory system allows us to effectively live, move and undertake everyday tasks and perform in a wide variety of physical activities.

Athletics The Marathon A full marathon run is 26.2 miles. In order to allow the body to complete such a demanding task the circulatory system must: Supply the working muscles, especially in the legs and arms, with greater supplies of both oxygen and glucose so they can continue to contract and create movement. Remove lactic acid and carbon dioxide from the body so the athlete can continue to run well and without pain. Reduce body temperature while running via the blood and sweating, so running speed can be maintained.