THE HEART THE CIRCULATORY SYSTEM
There are three primary closed cycles: 1) Cardiac circulation pathway of blood within the heart 2) Pulmonary circulation blood from the heart to lungs and back 3) Systemic circulation blood from the heart to the rest of the body There are three main elements to a circulatory system: 1) Transport medium fluid that transports materials throughout the body 2) Transport vessels a network of tubes in which the fluid circulates 3) A pumping mechanism pump that pushes fluid through the tubes 2
The Anatomy of the Mammalian Heart
T/F Your heart temporarily stops when you sneeze.
T/F Your heart can t beat without you.
T/F Females hearts beat faster than males.
There are three primary closed cycles: 1) Cardiac circulation pathway of blood within the heart 2) Pulmonary circulation blood from the heart to lungs and back 3) Systemic circulation blood from the heart to the rest of the body
What controls the heart? INTERNAL > EXTERNAL Sinoatrial node (S-A node) stimulates muscle fibres to contract and relax rhythmically. Acting as a pacemaker it gives electrical impulse to both atria and causes them to contract simultaneously. The pulse reaches the atrioventricular node (A-V node) which contracts the ventricles.
Lubb-Dubb (also know as the cardiac cycle) 1. Atria relax and fill with blood 2. As they fill the walls contract 3. AV valves forced open 4. Blood pumped into ventricles 5. As they fill the walls contact 6. AV valves forced shut (Lubb), blood pumped into semi-lunar valves 7. When ventricles relax (volume increases, pressure decreases) semi-lunar valves close to prevent back flow (Dubb) Systole = contraction Diastole = relaxation
ECG/EKG Electrocardiographs can monitor all of the impulses P wave - atrial contraction QRS wave - ventricular contraction T wave - ventricular recovery
T/F Broken hearts are physically possible.
Broken Heart Syndrome Also called also called stress-induced cardiomyopathy or takotsubo cardiomyopathy, can strike even if you re healthy. Sudden, intense chest pain as a reaction to a surge of stress hormones (feels like a heart attack). A part of your heart temporarily enlarges and doesn t pump well, while the rest of your heart functions normally or with even more forceful contractions.
also known as acute myocardial infarction (AMI) Flow of blood to a section of the heart becomes blocked and the heart can t get oxygen. The interrupted blood flow can damage or destroy part of the heart muscle. Symptoms: pain/pressure in chest, arms, neck, jaw, back; shortness of breath, lightheadedness, fatigue, shortness of breath etc. Causes: heart diseases, drama, respiratory illness etc.
Coronary Heart Disease The coronary arteries supply blood to the heart muscle. These may become blocked by a buildup of fatty plaque containing cholesterol. If a coronary artery is blocked, the blood supply to part of the heart muscle is cut off. That part of the heart cannot continue to contract, causing a heart attack. Causes: poor diet (saturated fats)
Heart Attack Circulation vs Electrical When the heart malfunctions and suddenly stops beating. It is triggered by an electrical malfunction in the heart that causes an irregular heartbeat.
Cardiopulmonary Resuscitation (CPR) CPR is a combination of techniques, including chest compressions, designed to pump the heart to get blood circulating and deliver oxygen to the brain. There is usually enough oxygen still in the blood to keep the brain and other organs alive for a number of minutes, but it is not circulating unless someone does CPR.
Automated External Defibrillator (AED) A portable device that checks the heart rhythm and can send an electric shock to the heart to try to restore a normal rhythm. AEDs are used to treat sudden cardiac arrest.
Heart Health
Smoking Makes the heart work harder, increases the risk of cardiovascular diseases - damaging the lining of arteries (builds up fatty materials) - carbon monoxide in smoke reduces amount of oxygen in blood - nicotine stimulates produce to produce adrenaline making the heart beat faster (raising blood pressure) - blood more likely to clot
Artificial Hearts Mechanical device that is implanted to help or replace a failing heart by adding an extra ventricle to help pump blood OR replace the heart entirely. Powered by either compressed air or electricity. Usually used as a bridge until transplants are available.
3D Printed Researchers have developed a silicone heart that beats almost like a human heart. This artificial heart has a right and a left ventricle separated by an additional chamber that fills and deflates to create the pumping action. Weighs the same as a natural heart.
1) Test Questions