Cardiovascular System. Supplementary Information

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1 Cardiovascular System Supplementary Information

2 THE CARDIOVASCULAR SYSTEM - 1 -

3 THE CARDIOVASCULAR SYSTEM FUNCTION Transport system carrying nutrient, gases, hormones and waste products to and from the body tissues Helps prevent disease Helps regulate body temperature ANATOMY Heart Vessels o Capillaries o Veins o Arteries Blood THE HEART Cardiac Muscle o Self stimulating o Never fatigues o Receives own blood supply via coronary arteries Double Pump o Left side pumps blood around body (systemic circulation) o Right side pumps blood to lungs (pulmonary circulation) - 2 -

4 THE CARDIOVASCULAR SYSTEM THE STRUCTURE OF THE HEART Four chambers o Right and left atria o Right and left ventricles Valves Septum Pericardium Myocardium Endocardium - 3 -

5 BLOOD FLOW THROUGH THE HEART RIGHT SIDE: 1. Venous blood from body enters right atrium 2. Blood passes through tricuspid valve into right ventricle 3. Blood leaves pulmonary artery to go to the lungs Blood exchanges CO 2 for O 2 in lungs and then returns to: LEFT SIDE: 1. Blood from lungs enters left atrium via pulmonary veins 2. Blood passes through mitral valve into left ventricle 3. Blood is pumped out of left ventricle into aorta to travel around body - 4 -

6 BLOOD CIRCULATION - 5 -

7 THE CARDIO-VASCULAR SYSTEM ARTERIES Carry blood away from the heart Carry oxygenated blood- except pulmonary artery Thick-walled, muscular and elastic tissue Under high pressure Divide into smaller vessels called arterioles, and then into capillaries CAPILLARIES Tiny vessels Permeable Exchange of gases/nutrients and waste materials Unite to form venules and venules form veins VEINS Return blood from tissues to heart Carry de-oxygenated blood - except pulmonary veins Thin walls Contain valves Under low pressure BLOOD Blood consists of cells suspended in a clear fluid called plasma - 6 -

8 THE CARDIO-VASCULAR SYSTEM COMPOSITION OF BLOOD PLASMA = 55% of blood volume Plasma is made up of 90% water + Plasma Proteins Salts Fats Enzymes Urea/uric acid Hormones Amino Acids Vitamins Glucose Minerals Gases CELLS Red cells called ERYTHROCYTES o Transport oxygen to tissues o Formed in bone marrow o No nucleus o Lifespan of 120 days o million per mm 3 o Require iron, vitamin C, vitamin B12, folic acid for formation White cells called LEUCOCYTES o Defence and protection o Ingest bacteria Phagocytes o Formed mainly in bone marrow, except lymphocytes (formed in lymph nodes and spleen) o Lifespan hours - months o Numbers increase during period of infection, 5,000-10,000 per mm 3-7 -

9 THE CARDIO-VASCULAR SYSTEM Platelets also called THROMBOCYTES o Prevent haemorrhage o Repair damaged blood vessels o Formed in bone marrow o Lifespan about four days o 250, ,000 per mm3 BLOOD PRESSURE As blood flows it exerts pressure on the walls of the blood vessels. Varies rhythmically with heartbeat: o Greatest as left ventricle contracts (systole) o Lowest as left ventricle relaxes (diastole) Blood pressure affected by: o Cardiac output o Blood volume o Blood viscosity o Blood vessel size and elasticity The rate at which the heart beats can be determined by taking the pulse. Normal rates in adults at rest are between but obviously vary according to many things such as emotion, general health and stimulants such as caffeine. Very fit people such as athletes may well have resting pulse rates below

10 Additional Information for VTCT Qualification Sometimes during bodily processes there needs to be a diversion of blood away from the areas not involved in order to provide a better blood supply to those areas that are active. By causing the small arterioles to constrict or dilate a considerable alteration in blood flow to the area they supply occurs, e.g. during digestion blood is diverted to those organs involved such as the stomach and intestines and away from areas such as the skeletal muscles. This is why exercising too soon after eating may cause cramps. Erythema Erythema is the reddening of the skin caused by vasodilation in the arterioles which then causes congestion in the tiny capillaries. It can happen during massage but also due to exercise, infection, allergies and radiotherapy treatment - 9 -

The Cardiovascular System home study course

The Cardiovascular System home study course harmony house holistic therapy treatment centre and training academy www.harmony-house.org 1 Copyright 2010 by Mark and Katy Rogers All rights reserved. No part