The horse's cardiovascular system is designed to transport oxygen from the lungs to body tissues via the blood. “Blood is the primary carrier throughout the body of essential water, oxygen, nutrients, chemical regulators and waste products. Blood is propelled along blood vessels by the pumping action of the heart” (Hastie, 2012)Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay Blood vessels are made up of arteries, veins, and capillaries. Arteries are the largest vessels; their purpose is to evacuate oxygenated blood from the heart, the blood in these vessels is under high pressure. The walls of arteries are made up of smooth muscle and elastic fibers that contract and relax to circulate blood through the cardiovascular system. The veins are responsible for transporting deoxygenated blood to the heart; the layers of the vein are much thinner and less elastic than those of the arteries. Veins contain valves that prevent blood from flowing backwards; arteries do not have this function; Blood in veins is transported at a much lower pressure than in arteries. Capillaries are the smallest of blood vessels; their cells are one cell thick. Their function is to enable easy exchange of components such as nutrients, oxygen, carbon dioxide and salts and to enable the removal of waste products from cells between body tissues and blood. The equine heart is made up of two chambers made up of atria and ventricles. The atria are the chambers that collect blood returning to the heart and the ventricles are the chambers that pump blood from the heart back to the body. The right atrium receives deoxygenated blood from the network of veins returning to the heart; the atrium pushes blood past the tricuspid valve into the right ventricle. From the right ventricle, blood is pushed through the pulmonary arteries to the lungs where the blood is oxygenated with oxygen inhaled via respiration. Oxygenated blood is returned to the left atrium via the pulmonary veins and then supplies the left ventricle via the mitral valve. To complete the cycle, the left ventricle pumps oxygenated blood past the aortic valve and throughout the body via the aorta. The aim of this study is to establish whether the horse's heart rate is affected by the pace at which it moves. Previous studies investigating heart rate variability have been used to assess the stress response in horses with laminitis after short- and long-term treatments; results showed that heart rate decreased after treatments (Gehrke et al., 2011). Another looked at heart rate variability in relation to stress and well-being; their results conclude: “HRV analysis in horses appears to be a sensitive measure of responses to physical and emotional stress” (von Borell et al., 2007). Studies have also been conducted on heart rate monitors to evaluate their accuracy in recording heart rate data. The results of (Evans et al., 1986) showed that the four heart rate monitors (PEH 100, PU10, HR14 and HRM-7) used in their experiment had significant correlations with heart rate recordings taken by electrocardiography simultaneous telemetry (ECG) that might suggest they are accurate, but there are still areas of error in the recordings. More recent experiments using polar equine monitors, used in this experiment, have been found capable of obtaining a.