Sinoatrial node

EXERCISE 6 Cardiovascular Physiology NAME: LAB TIME/DATE: 1. Define each of the following terms: • autorhymicity- The heart is autorhythmic. This means it generates its own rhythmic action potential independent of the nervous system. • sinoatrial node- is the impulse-generating (pacemaker) tissue located in the right atrium of the heart, and thus the generator of normal sinus rhythm. • pacemaker cells- are specialized cells that cause involuntary muscles and tissues to contract or dilate.

the body. The electrical impulse initiates in the Sinoatrial node (SA node), which is located in the posterior wall of the right atrium, near the superior vena cava. It is also known as being the physiologic pacemaker of the heart and has an intrinsic firing rate of 60-100 impulses/min. From the SA node, the electrical impulse flows directly to the Atrioventricular node (AV node) with the guidance of intercalated discs and gap junctions. The AV node is located in the back section of the interatrial

to the heart will freely flow from the atria to the ventricles as the AV valves kept open by the pressure in the atria ▪ The sinoatrial node (pacemaker) receives signals to fire when the ventricles are almost full (~70%) ▪ The contraction of the atria (atrial systole) causes blood to fill the ventricles to the maximum ▪ The signal from the SA node is transferred to the AV node and then via Purkinje fibres to cause the delayed contraction of the ventricles ▪ As the ventricles contract, the increase

Atrial fibrillation is a condition that the heart beat irregularly and often rapidly. Normally, a sinoatrial node (SA node) in the right atrium of the heart acts as the heart’s natural pacemaker and generates electrical signals to start the heart beating in an organized way. It allows atria to contract and squeeze regularly traveling the electrical signals through the atrioventricular node (AV node) which is situated in the centre of the heart between the atria and ventricles, the electrical signals

heart to beat either too fast, too slow or irregular. There a two different types of cardiac arrhythmias; supraventricular and ventricular. The supraventricular arrhythmias occur when electrical abnormalities are generated in the sinoatrial node, atria, atrioventricular node, and the junctional tissue in the heart. The ventricular arrhythmias are generated in the ventricular conduction system and the ventricle. Due to the fact the ventricle pumps blood to the heart, if the blood isn’t pumped effectively

The signal moves quickly from the SA node through the atria where it experiences a slight delay when it reaches the AV node and it must pass into fibers with smaller diameters. The signal then quickly resumes along its path through the AV bundle branches apex and base of the ventricles contraction begins. 7. What

Daphnia and Additives Lab Purpose The purpose of this lab is to test what effect of Nicotine, Acetylcholine, Epinephrine, Caffeine, and Ethanol on an organism’s heart rate. Materials * Microscope * Eye dropper * Pipet * Cotton balls * Depression slide * Beakers * Daphnia * Water * Five additives: Nicotine, Acetylcholine, Epinephrine, Caffeine, Ethanol Procedure 1. Put on safety goggles. 2. Catch a living Daphnia. 3. Transfer to a depression

world allowing the nurse and other trained medical professionals to interpret what the heart is doing. In a normal strip, one can clearly identify a P wave before every QRS complex, which is then followed by a T wave; in Atrial Fibrillation, the Sinoatrial node fires irregularly causing there to be no clear P

into 5 main steps. First the Sinoatrial Node (SA Node) sends out a signal from its electrical system. It is commonly known as the pacemaker of the heart, if the SA Node is not working properly it will be replaced by a pacemaker to simulate the same electrical signal. The signal then travels to the Atrioventricular Node (AV Node) that is located at the top of the septum. The septum divides the left and right ventricles. If the SA Node is not working properly, the AV Node will take over and keep the

The SA node is the primary pacemaker of the heart. It starts the heartbeat by spontaneously contracting, causing the rest of the heart to contract in a wave. The wave spreads through the atria before reaching the atrioventricular node, or AV node, located just above the right ventricle. The AV node focuses the wave into the ventricles, contracting the ventricles. Should the SA node fail, the AV node can take over as the primary pacemaker at a rate