Circulatory System Notes PDF

 The heart is the hardest working muscle in the entire body. Even at rest it works harder than the leg muscles do during a sprint The heart is about the size of a clenched fist. Your heart beats more than 100 000 times each day. The average-body has about 100 000 km of blood vessels. The aorta...

 The heart is the hardest working muscle in the entire body. Even at rest it works harder than the leg muscles do during a sprint The heart is about the size of a clenched fist. Your heart beats more than 100 000 times each day. The average-body has about 100 000 km of blood vessels. The aorta, the largest artery, is almost the diameter of a garden  In a day, blood travels about 19 000 km through the body. It takes only about 20 s for a red blood cell to completely circuit the body. There are four major blood groups A, B, AB and O. Type O is considered the universal donor; type AB is the universal recipient. About 8 million blood cells die every second and are replaced by new The function of Lungs circulatory system: Transports oxygenated blood (from lungs) through the body and Body deoxygenated blood (from the body to the lungs). Transport of nutrients from the intestines to the body  Regulates body temperature.  Circulates hormones.  Transports white blood cells to the sites of infection.  What is the circulatory system made of? 1.The heart which pump the blood 2.Blood vessels in which blood flows. 3. Blood which transport materials. The main goal of the circulatory system is to circulate oxygen rich blood or oxygenated blood to your cells and get rid of carbon The circulatory system is composed of two Circuits: 1.Pulmonary Circuit 2. Systemic Circuit.  Pulmonary Circuit Lung - The system of blood vessels that carries deoxygenated blood to the lungs and oxygenated Body cells blood to the heart.  Systemic Circuit Lung The system of blood vessels that carries oxygenated blood to the organs of the body and deoxygenated blood Body cells back to the heart.  How does this system work? pulmonary artery lungs pulmonary vein head & arms aorta main vein Right Left liver digestive system kidneys legs Circulatory System  The HEART Heart is a double pump and is located in Chest/Thoracic cavity. Heart contains cardiac muscle that contracts to make blood move around the body.  The right and the left side of the heart are separated by a wall known as septum. Is covered by pericardiu m.  The HEART Two upper chambers are called atria (singular atrium :). right atrium left atrium right left ventricle ventricle Two lower chambers are ventricles.  Superior  AORTA:The Vena Cava:- major artery Large vein in the body that carries that carries dirty blood clean blood to from the the body from the upper organs Pulmonary heart. artery to the heart. Carry DIRTY blood to the lungs Inferior from the heart. Vena Cava:- Pulmonary Veins Carry Large vein oxygenated blood from the that carries lungs to the heart. Close up of Heart Valve  External view of the heart superior vena cava pulmonary artery aorta pulmonary pulmonary vein vein coronary right atrium artery left inferior ventricle vena cava right ventricle apex  How does the Heart work? STEP ONE blood from the lungs blood from the The heart beat begins body when the heart muscles relax and blood flows into the atria.  How does the Heart work? STEP TWO The atria then contract and the valves open to allow blood into the ventricles.  The valves close to stop blood STEP THREE flowing backwards. The ventricles contract forcing the blood to leave the heart. At the same time, the atria are relaxing and once again filling with blood.  BLOOD VESSELS Blood from the heart gets around the body through blood vessels. There are 3 types of blood vessels a. ARTERY b. VEIN c. CAPILLARY  Arteries carry blood away from the heart. Thick outer wall Thick inner layer of Narrow central tube muscle and elastic made of epithelial fibres. tissues The thick muscle The elastic fibres can contract to allow the artery to push the blood stretch under high along. pressure.  Atherosclerosis is a disease of the arteries. Fat deposits inside arteries. Plaques develop in inner wall of the arteries, narrowing their channel – increases blood pressure ,increases risk of heart attack, stroke, kidney damage Veins carry blood towards the heart from organs. Thin inner layer of Thin outer wall muscle and elastic Made of connective fibres tissues Wide central tube Veins have valves which act to stop the blood from going in the wrong direction. Veins handle a very low blood pressure When blood is flowing against gravity, or when a vein is squeezed by muscle action, there is a risk that blood will flow in the wrong direction. Veins have valves to prevent backflow. vein vein valve valve open closed Body muscles surround the veins so that squeeze the veins and push the blood along the vessel.  If the one-way valve becomes weak, some of the blood can leak back into the vein, collect there, and then become congested or clogged. This congestion will cause the vein to abnormally enlarge. These enlarged veins can be either varicose veins or spider veins. Capillaries carry blood to and from the body cells and link arteries with veins. They exchange materials between the blood and other body cells. The wall of a capillary is only one cell thick. Capillaries handle a low blood pressure.  The CAPILLARY A collection of capillaries is known as a capillary bed or network. body cell  HEART RATE: Expressed as beats per minute. 72 beats/min It its set up by sinoatrial node (SA-Node) or the pacemaker located in the right atrium. Changes during rest activity exercise Detected by taking pulse: – Radial artery (wrist) – Carotid artery (neck) What is your pulse? Change in the diameter of the arteries that can be felt on the body's surface as heart contract. Average healthy adult – 60-80beats/min at rest.  HEART SOUNDS : Lubb-dubb heart sounds are caused by closing of heart valves. Stethoscope is used to listen to heat sounds. Steps: Atria relax, fill with blood – diastole Atria pushes blood into ventricle Ventricles contract, pushing blood into arteries – systole Increased pressure during systole causes AV valves to close – lubb sound Ventricles relax, pressure decreases, causes semilunar valves to close – dubb sound  BLOOD PRESSURE: The force of the blood on the walls of the arteries. Is measured using a Sphygmomanometer or blood pressure cuff. Stethoscope is used to listen to the sounds of the blood rushing through the artery. Sphygmomanometer Systolic blood pressure is the pressure when the heart contracts while pumping blood. Diastolic blood pressure is the pressure when the heart is at rest between beats. Categories for Blood Pressure Levels in Adults* (In mmHg, millimetres of mercury) Systolic Diastolic Category (Top number) (Bottom number) Normal Less than 120 Less than 80 Prehypertension 120-139 80-89 High Blood Pressure Systolic Diastolic Stage 1 Hypertension 140-159 90-99 Stage 2 Hypertension 160 or higher 100 or higher  what’s in digested white blood cells red blood food cells oxygen waste (urea) carbon dioxide platelets plasma hormones  The Blood red blood cell white blood cell platelets plasma  Red Blood Cells contain hemoglobin, a a biconcave disc that is molecule specially designed round and flat without to hold oxygen and carry it a nucleus to cells that need it. can change shape to an amazing extent, without breaking, as it squeezes single file through the capillaries. White Blood Cells there are many different types and all contain a big nucleus. the two main ones are the lymphocytes and the macrophages. macrophages ‘eat’ and digest micro- organisms. some lymphocytes fight disease by making antibodies to destroy invaders by dissolving them. other lymphocytes make antitoxins to break down poisons. Platelets Platelets are bits of cell broken off larger cells. Platelets produce tiny fibrinogen fibres to form a net. This net traps other blood cells to form a blood clot.  Plasma It also contains useful things like; carbon dioxide A straw-coloured glucose liquid that amino acids carries the cells and the platelets proteins which help blood minerals clot. vitamins hormones waste materials like urea.  SUMMARY copy and complete the following; Arteries take blood ______ from the heart. The walls of an artery are made up of thick _________ walls and elastic fibres. Veins carry blood ________ the heart and also have valves. The _________ link arteries and veins, and have a one cell thick wall. Blood is made up of four main things ______, the liquid part of the blood; Red Blood Cells to carry ______; White Blood cells to protect the body from disease and _________ to help blood clot.