Cardiovascular System (2022) PDF

The Cardiovascular Sy  The Cardiovascular System The organ system that is made up of the heart, the blood, and the blood vessels The circulatory system connects all parts of the body. Oxygenated blood is shown in red (left side of body). Deoxygena...

The Cardiovascular Sy  The Cardiovascular System The organ system that is made up of the heart, the blood, and the blood vessels The circulatory system connects all parts of the body. Oxygenated blood is shown in red (left side of body). Deoxygenated blood is shown in blue (right side of body).  Function of the circulatory system: To transport substances around the body To move nutrients to all of the body’s cells Regulation of body temperature Transport of disease-fighting white blood cells to areas of the body where they are needed (i.e. viruses/bacteria) How is this done? Blood flows through lungs, picks up oxygen, then flows to heart to pump to body to deliver it to active cells  Parts of the Cardiovascular (circulatory) system 4 parts of the circulatory system: blood, heart, and blood vessels, lungs 1) Heart pumps blood through large vessels (arteries) AWAY from heart to body 2) Blood exchanges substances, in smallest vessels (capillaries), with surrounding tissues 3) Blood then flows into larger vessels (veins) and returns TO the heart 4) Blood then goes to lungs for more oxygen, back to heart and cycle continues  The Heart Located slightly left of middle of the chest -about the size of your fist (weighs 9 oz) Protected by sternum Surrounded by pericardium Muscular part is myocardium (cardiac muscle) coronary artery supplies heart with O2, cardiac vein removes CO2 Has 4 chambers – 2 atria and 2 ventricles  3 Layers of the Heart (pericardium, myocardium, endocardium) Heart Diagram  Chambers of the Heart Atria (atrium)– 2 top chambers; -right atrium gets deoxygenated blood from the vena cava from body -left atrium gets oxygenated blood from the pulmonary vein from the lungs Ventricles – 2 lower chambers receive blood from atria -right ventricle pumps deoxygenated blood to the pulmonary artery to lungs for oxygen - left ventricle (thicker) pumps oxygenated blood to the aorta to send to the body and cells  Myocardium -Both sides of heart are separated by Specialized muscle tissue (cardiac muscle) that a thick muscular forms the walliscalled heart. The heart the considered a “double pump” that is divided into right and left sides. septum (so blood from each side won’t mix) Pulmonary Circulation ▪Right side The main of heart function – deoxygenated of the right side of the heart is to pump blood deoxygenated (blood blood, which from body thenhasoutjust to returned from the body, and is going to the lungs. lungs to pick up oxygen);bluish ▪Left Systemic Circulation side of heart – oxygenated blood (blood The role from of the left side lungs is pumped of the heart is to pump outoxygenated blood, which has just returned from the lungs, and is body) to rest of ;brighter going to the red rest of the body. Blood Flow Through the Heart: Khan Academy https://www.khanacademy.org/science/health-and-medicine /circulatory-system/circulatory-system-introduction/v/flow-t hrough-the-heart Blood is delivered to the right It passes through the atrium from the superior and tricuspid valve and enters the inferior vena cava. right ventricle. From there, the blood is pumped through the The blood returns from the lungs pulmonary semilunar valve and through the pulmonary veins to out through the pulmonary the left atrium. arteries to the lungs The blood is then pumped out It then passes through the through the aortic semilunar valve bicuspid valve and enters into into the aorta and throughout the the left ventricle. systemic circulation.  Blood Vessels Three types of blood vessels from a network of tubes throughout the body to transport the blood. 1) Arteries 2) Veins 3) Capillaries  Elastic blood vessels Arteries that carry blood AWAY from the heart Artery expands with surge of blood during contraction of ventricles, then snaps back during relaxation of ventricles Under a great amount of pressure Have thicker walls to withstand pressure; will spurt when cut Can vary in size  Elastic blood vessels that carry blood Veins TOWARD the heart Can’t contract to help move blood back to heart Have one-way valves to prevent blood from flowing backward Blood is at a lower pressure Thinner wall than arteries Can vary in size Capillaries Extremely small blood vessels located within the tissues of the body Fine network Transports blood from arteries to veins Exchange O2 with CO2 and nutrients with waste Thin walled Allow substances to diffuse between the blood and other body fluids and tissues Arterioles Arterioles are small vessels in the blood circulation system that branch out from arteries (that came from lungs) and lead to capillaries, where gas exchange eventually occurs. Surrounded by smooth muscle, arterioles are the primary site of vascular resistance. Venules Small blood vessels that branch out from capillaries and lead to veins with deoxygenated blood used by cells that are sent to lung for oxygen. Human Vascular System  Main Vessels of the Heart Pulmonary arteries – transport deoxygenated blood out of heart to the lungs to pick up oxygen Pulmonary veins – bring oxygenated blood back to the heart to be pumped out to the body Aorta – largest blood vessel (artery) in body; where all blood going to the body tissues leaves the heart (brachiocephalic, common carotid, subclavian) Vena Cava- largest vein in the body carrying blood back to heart from body (superior vena cava from top half of body and inferior vena cava from bottom half)  Valves of the Heart Valves control the flow of blood through the heart in the correct direction 4 valves of the heart: 2 Atrioventricular valves (AV valves) 1.Tricuspid valve (3 flaps)- between the right atrium and right ventricle 2. Bicuspid valve (2 flaps and called mitral valve) between the left atrium and left ventricle 2 Semi-Lunar valves 1. Pulmonary valve- between the right ventricle and the pulmonary artery 2. Aortic valve -between the left ventricle and the aorta Tricuspid Valve Tricuspid Valve Bicuspid Valve  Varicose Veins Varicose Veins occur when valves become faulty and blood begins to pool in areas of the veins. If the walls of the vein become stretched and less flexible (elastic), the valves can weaken. A weakened valve can allow blood to leak backward and eventually flow in the opposite direction. When this occurs, blood can accumulate in the vein(s), which then become enlarged and swollen. Compression socks and clothes help blood flow  Blood A type of connective tissue that circulates throughout body (about 9 pints at a time) Both fluid and solid portion It consists of four components: 1) Plasma 🡪 55% of blood volume 2) red blood cells (erythrocytes) 🡪 44% of blood 3) white blood cells (leukocytes)1% 4) Platelets (thrombocytes)0.5% } 1% of blood volume  Red Blood Cells (Erythrocytes) perform the most important blood duty Specialized for oxygen transport A single drop of blood contains millions of red blood cells which are constantly traveling through your body delivering oxygen/nutrients and removing waste/CO2 Contain hemoglobin (protein) which allows cells to pick up oxygen and also transports some of the carbon dioxide waste (iron helps hemoglobin) RBCs are the most plentiful of the body’s blood cells.  White Blood Cells (Leukocytes) Part of the body’s response to infection 5 types of WBCs Make up about 1% of blood volume but this can increase more than double when your body is fighting infection white blood cells are continually on the lookout for signs of disease. When a germ does appear, WBCs have a variety of ways by which they can attack. ○ Some will produce protective antibodies that will overpower the germ. ○ Others will surround and devour the bacteria.  Platelets (Thrombocytes) Third major substance (clotting cells) in formed portion of blood irregularly-shaped, colorless bodies present in blood Their sticky surface lets them, along with other substances, form clots to stop bleeding. Human body does not handle excessive blood (hemorrhage) loss well. Therefore, the body has ways of protecting itself. When sudden blood loss occurs, the blood platelets kick into action. When bleeding from a wound suddenly occurs, the platelets gather at the wound and attempt to block the blood flow. The mineral calcium, vitamin K, and a protein called fibrinogen help the platelets form a clot. Platelets (continued) A clot begins to form when the blood is exposed to air. The platelets sense the presence of air and begin to break apart. They react with the fibrinogen to begin forming fibrin (an insoluble protein) which resembles tiny threads. The fibrin threads then begin to form a web-like mesh that traps the blood cells within it. This mesh of blood cells hardens as it dries, forming a clot, or "scab”.  Plasma protein-rich, yellowish, clear liquid 90% water and essential ingredient for human survival. It might seem like plasma is less important than the blood cells it carries, but you can't have one without the other. contains dissolved salts and minerals like calcium, sodium, magnesium, and potassium. Also contains proteins called albumin, globulins and fibrinogen Microbe-fighting antibodies travel to the battlefields of disease by hitching a ride in the plasma.  The Composition of Blood The Composition of Blood The Composition of Blood  Heart Rate (pulse) Pulse- a rhythmic beating felt at an artery as the heart pumps blood Average adult should have 60-80 beats/min Bradycardia- very slow heart rate 100 bpm Pulse can easily be felt (palpated) on radial or carotid artery usually ( or femoral, popliteal, temporal, brachial) Stethoscope- used to hear heart rate  Measuring Your Pulse 1. Find your pulse. You can find it on your neck or wrist. 2. When I say go, count the number of beats that occur within a 30 sec period. 3. Multiply that number by 2 to determine your # of beats per minute. A healthy heart will have 60-100 bpm. Highly conditioned athletes can have a heart rate of 40-60 bpm. Your heart is a muscle that can be trained. The more you exercise, the stronger and more efficiently it can pump oxygenated blood to your tissues. Note: Factors that will affect “resting HR” – exercise within 2hrs of measurement, caffeine, sitting or standing for long periods of time.  Blood Pressure pressure exerted by the circulating volume of blood on the walls of the arteries Systolic- maximum pressure of the blood exerted against the artery; ventricles contract; top number of reading (120);”lub” sound, Diastolic- minimum pressure exerted on artery; ventricles relax and refill; bottom number(80).”dub” sound Average blood pressure reading for an adult is 120/80 mmHg (systole/diastole) Sphygmomanometer- instrument used to measure blood pressure  Hypertension: the term which refers to high blood pressure. High Hypertension-High blood pressure is considered anything over 140/90 mmHg. -causes include obesity, smoking, lack of physical activity, stress, too much salt in diet, genetics -can have serious risks which include risk of heart attack or stroke, aneurysm, heart failure Hypotension: refers to low blood pressure which is considered anything less than 90/60 mmHg. -causes include hormones, pregnancy, medications -can cause dizziness and lightheadedness, which is an indication that there is not a great deal of blood flow to the heart or brain. -low blood pressure ultimately isn’t a problem unless it’s causing serious symptoms or is occurring in the elderly. Vasodilation- widening of arteries when muscle contract Vasoconstriction- narrowing of arteries when muscle relaxes Certain conditions or drugs can cause vasodilation or vasoconstriction Hy Pacemakers Pacemakers are machines required for people who require the rhythm of their heart to be monitored. When necessary, the pacemaker will generate an electrical impulse in order to trigger a regular heartbeat.  Tissues of the Heart Heart is made up of three different types of tissues: 1) Cardiac muscle tissue 2) Nerve tissue 3) Connective tissue a) Cardiac Muscle Tissue Unique tissue found only in the heart Arranged in a network to allow contractions Contracts at the same time, which moves blood around the body b) Nerve Tissue Nerve tissue is made up of nerve cells (neurons) and is used to carry "messages" to and from various parts of the body. c) Connective Tissue Muscles and nerves are covered by a smooth layer of epithelial tissues. This layer prevents friction, protects the heart from damage, and allows blood to flow freely. Connective tissue supports other tissues and binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of the various passages inside the body).  Diseases & Disorders of the Cardiovascular System A healthy circulatory system is essential for the body, since it is responsible for supplying nutrients and oxygen to the body cells and tissues. With each heartbeat, blood is pumped into the blood vessels in order to deliver the essential nutrients required for survival to the various parts of body. Due to the importance of the circulatory system, it is often referred to as 'the lifeline of the body'. However, there are many conditions that can affect the function of the circulatory system. Coronary Artery Disease Coronary artery disease is a condition in which plaque builds up inside the coronary arteries. These arteries supply your heart muscle with oxygen-rich blood. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. When plaque builds up in the arteries, the condition is called atherosclerosis.  Coronary artery disease (also known as atherosclerosis) involves a gradual narrowing of the coronary arteries resulting from the accumulation of hard deposits of cholesterol (plaque), on the lining of the blood vessels.  Heart Attack -occur most often as a result of a condition called coronary artery disease where plaque builds up over many years on the inside walls of the coronary arteries (the arteries that supply blood and oxygen to your heart). Eventually, an area of plaque can rupture, causing a blood clot to form on the surface of the plaque. If the clot becomes large enough, it can mostly or completely block the flow of oxygen-rich blood to the part of the heart muscle fed by the artery. Called an INFARCT. Dead heart muscle cannot regenerate  Coronary Circulation Like all tissues in the body, the heart also needs to be supplied with O2. There is a misconception that the blood that is flowing through the heart is what is providing the heart with the O2 it’s tissues needs. This is false! The right & left coronary arteries nourish the myocardium of the heart. The left & right cardiac veins remove waste from the myocardium. i  Coronary Circulation -system of vessels that supply essential materials via blood to the heart muscle itself is called the coronary circulation. -Serious health repercussions and even death can occur if a narrowing or blockage of blood vessels restricts the flow of blood to the heart muscle. Eg. a heart attack (a myocardial infarction) can result when blood flow to a section of the heart muscle becomes blocked due to a plaque buildup or some other reason. Symptoms of a Heart Attack Chest pain/pressure (angina pectoris) Shortness of breath Nausea Anxiety Upper body pain Abdominal or stomach pain Sweating Dizziness Unusual fatigue  Heart Attack Risks Age Gender Unhealthy diet, high blood pressure or high cholesterol and obesity Past heart or health conditions like blood clots or diabetes Stress Drugs (like smoking) Lack of exercise Genetics  Blockages in the Body Blockage in the heart= (angina pectoris-infarct-heart attack Blockage to the brain= ischemia (stroke) Blockage throughout the body= embolism Other health issues that affect Heart Hyperglycemia- excessive sugar in the blood Hypoglycemia- low amount of sugar in blood  Exercise For the Heart 30 mins of aerobic (non-stop) 3-5 times per week will improve endurance of heart, using large muscle groups Increases heart size and # of RBC reduces heart disease and lowers blood pressure prevents weight gain and raises HDL Improves self esteem and lowers stress Training should be between 65-80% of aerobic capacity. Target heart rate is 220-age x 0.65-0.80