Transcript Heart
What’s in the circulatory system? • 1. Heart 2. Blood vessels 3. Blood • Myocardium – heart muscle that pumps blood through the body • Pericardium (‘peri’ = around; ‘cardi’ = refers to heart) – Membranous sac surrounding the heart Functions of the circulatory system… DELIVER MATERIALS Red Blood Cells – (Erythrocytes) Red blood cells – carry Oxygen to the body and pick up Carbon Dioxide. Cells trade the Carbon Dioxide for Oxygen in the LUNGS What does oxygen do for us? Oxygen helps our body to make energy White Blood Cells – (Leukocytes) Fight disease and foreign objects in the body Platelets – (Thrombocytes) Assist in blood clotting Plasma – strawcolored fluid; 90% water – helps control your body temperature Blood Vessels Tubes that carry blood – capillaries, arteries and veins 1. Arteries Carry blood away from the heart Valve Muscle 2. Veins Carry blood to the heart 3. Capillaries Smallest vessels that are very thin & allow oxygen and carbon dioxide to pass through the walls • A buildup of plaque in the arteries • Plaque can detach, which causes a blood clot • If a clot falls away from the arterial wall and moves through the body, it is called an embolism • Dangerous! Can become lodged and cut off the supply of RBC’s, which cuts off O2 High Blood Pressure • Heart produces pressure on the arteries when it contracts • We measure the pressure exerted by the heart when it contracts (systolic pressure) and when it relaxes (diastolic pressure) • Systolic / Diastolic • Normal for teens and adults is 120/80 or below • Sphygmomanometer Measuring Your Pulse • “Pulse” measures number of heartbeats – At rest is 60 – 100 BPM – Well-trained athletes can have a heart rate around 40 BPM • Activity/ Fitness level, Air temperature, Body position, Emotions, Body size, Medication use • Use carotid artery or radial artery Heart rate: 1,250 BPM Heart – has 4 chambers Ventricle - lower chambers of the heart Atrium - upper chambers of the heart Right and left sides from specimen’s viewpoint Pacemaker - small bundle of cells in the right atrium that starts each heartbeat Coronary arteries are the arteries that give the cardiac muscle oxygen Why would the heart need oxygen? When plaque blocks a coronary artery the heart muscle is not able to make enough energy and you have a heart attack What do you think causes the plaque to build up? Cardiovascular disease has been linked to smoking & high cholesterol In heart bypass surgery the blockage in the coronary artery is bypassed A vein is taken from the leg and is connected to the aorta and then to a place beyond the blockage. Angioplasty – where a balloon is blown up in side an artery. The balloon pushes the plaque to the sides, so the passage is clear. Deflated balloon in artery Balloon pushes plaque against artery wall It’s much easier to prevent heart disease than to cure it. Prevention starts at a young age – eat healthy, exercise, don’t smoke, and keep yourself away from secondhand smoke Respiratory System Gas Exchange Path of the Upper Respiratory System: 1. Air enters the mouth or nose (preferably) 2. Air continues down the pharynx past the larynx (voice box) and into the trachea (windpipe) 3. The lower end of the trachea splits into 2 bronchi Lower Respiratory: 4. The bronchi split off into several bronchioles 5. At the end of each bronchiole there is an air sac ALVEOLI Trachea Blood cells with Oxygen Capillaries Bronchioles Alveoli Oxygen in CO2 out Blood cells with CO2 The air sac is made up of several alveoli The alveoli have capillaries wrapped around them When you inhale, muscles in between your ribs contract and the diaphragm (a muscle below your lungs) contracts When you exhale the muscles in between your ribs relax and the diaphragm relaxes Asthma - respiratory disease in which certain airways in the lungs become constricted Bronchitis – mucous accumulates in the bronchioles and does not allow as much air to pass through Emphysema – the alveoli lose their elasticity Pneumonia – the alveoli fill with liquid (pus, mucous etc)