Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Coronary artery disease wikipedia , lookup
Heart failure wikipedia , lookup
Quantium Medical Cardiac Output wikipedia , lookup
Lutembacher's syndrome wikipedia , lookup
Myocardial infarction wikipedia , lookup
Electrocardiography wikipedia , lookup
Atrial fibrillation wikipedia , lookup
Dextro-Transposition of the great arteries wikipedia , lookup
3013Heartbeat activity Name:___________________________________ What causes a Heart beat? The atria and ventricles work together, alternately contracting and relaxing to pump blood through your heart. The electrical system of your heart is the power source that makes this possible. Your heartbeat is triggered by electrical impulses that travel down a special pathway through your heart: 1. SA node (sinoatrial node) – known as the heart’s natural pacemaker The impulse starts in a small bundle of specialized cells located in the right atrium, called the SA node. The electrical activity spreads through the walls of the atria and causes them to contract. This forces blood into the ventricles. The SA node sets the rate and rhythm of your heartbeat. Normal heart rhythm is often called normal sinus rhythm because the SA (sinus) node fires regularly. 2. AV node (atrioventricular node) The AV node is a cluster of cells in the center of the heart between the atria and ventricles, and acts like a gate that slows the electrical signal before it enters the ventricles. This delay gives the atria time to contract before the ventricles do. 3. His-Purkinje Network This pathway of fibers sends the impulse to the muscular walls of the ventricles and causes them to contract. This forces blood out of the heart to the lungs and body. 4. The SA node fires another impulse and the cycle begins again. At rest, a normal heart beats around 50 to 99 times a minute. Exercise, emotions, fever and some medications can cause your heart to beat faster, sometimes to well over 100 beats per minute. How fast the heart beats depends on the body's need for oxygen-rich blood! The more oxygen the body demands, the faster the heart beats to oxygenate the blood. Take your pulse . Place your index and middle finger of your hand on the inner wrist of the other arm, just below the base of the thumb. You should feel a tapping or pulsing against your fingers. Count the number of taps you feel in 10 seconds. Multiply that number by 6 to find out your heart-rate for one minute: Pulse in 10 seconds x 6 = ____ beats per minute (your heart-rate) When feeling your pulse, you can also tell if your heart rhythm is regular or not. My resting heart rate = Now plan an experiment to increase your heart beat. Do at least two variations of the experiment and chart your heartbeat. Hypothesis?_________________________________________________________________________________ ____________________________________________________________________________________________ Independent variable?_____________________ Dependent variable?__________________________ Create a chart of your data with appropriate headings and graph results on next page. Write a conclusion and include the hearts role in maintaining homeostasis.