Sinoatrial node

Circulation and respiration task 1. The pacemaker is a treatment for the heart disease called arrhythmia. An Arrhythmia is a problem with the rate or rhythm of the heartbeat. During an Arrhythmia, the heart can beat irregularly (either too fast or too slow). There are four types of Arrhythmia. premature arrhythmia – are extra heartbeats that begin in one of your hearts two lower pumping chambers (ventricles). These heartbeats disturb your normal heart rhythm which causes your heart rate to…

the intrinsic system consist of: sinoatrial node or SA node (found on the posterior wall of the right atrium functions to initiating depolarization impulse that produces an action potential spreading through the atria to the AV node as a cardiac pacemaker setting a pace of the hearts beat); intermodal pathway (found in the walls of the atria connecting the SA node to the AV node it functions in distributing an action potential to the atria’s contractile cells), AV node (found within the inferior…

The properties of cardiac muscle are always changing as a result of sympathetic and parasympathetic nervous stimulation and pharmacological drugs that alter or stimulate molecular mechanisms in the heart. In order to understand the mechanisms of the heart, we must experiment with the heart by observing the properties of cardiac cells and formulate hypotheses for their observed response. The structure of cardiac muscle consists of myocardial cells which have a nucleus, contractile filaments…

pressure decreases, no blood enters the ventricles, the ventricles then begin relaxing and the semilunar valves close due to pressure of blood found in the aorta. The heart also has a conduction system which allows a pulse to be generated by the sinoatrial node, which stimulated the cardiac muscle, aka the myocardium. The myocardium contracts while propagated which causes a rhythmic pulse in the cardiac…

blood from the aorta to the myocardium to keep contracting. The left coronary artery feeds most of the left ventricle, the septum and much of the conduction system. The right coronary artery feeds the right side of the heart, including the sinoatrial (SA) nodes. During diastole the coronaries arteries receive blood to flow freely into the muscle since it is in a relaxed state. During systole, the ventricle contracts and the aortic leaflets close the coronary arteries. The closing of the aortic…

electrical activity of the heart. The electrocardiogram displays several waves which consists of the P, QRS, and T wave. The P wave records what's happening in the heart. The Sinoatrial node depolarizes sending its signal around the atrial muscle; the atrial depolarizes and then contracts. The next step is the Atrioventriclar node depolarizing. It is going to send its signal through the conductive tissues causing the ventricle to contract. This is called the QRS complex. There is a great amount…

Lab Objective: The purpose of part one of this experiment is to illustrate the relationship between the electrical activity of the heart and the sounds the heart creates. This experiment also analyzes a subject’s physical fitness by measuring the amount of time a subject requires to return to resting level heart rate. Hypothesis: When recording the electrocardiogram for each subject, we expect to see normal sinus rhythm between P wave, QRS waves, and T waves. P waves should be succeeded by…

The Human Heart: A General Description The heart is the main organ of the cardiovascular system in the human body. Its primary function is to pump oxygen- and nutrient-rich blood throughout the 60,000 miles of blood vessels that make up this system ("Heart, 2015"). About the size of a clenched fist, the heart is located in the middle of the chest, between the lungs and nestled behind the ribcage. It lies a little to the left of the sternum. The shape of the heart is reminiscent of an upside…

One candidate biological system that may function to optimize social connections is parasympathetic activity, often conceptualized as the functioning of the vagus nerve and measured as respiratory sinus arrhythmia (RSA) or high-frequency heart rate variability (HF-HRV) at rest. The longest autonomic nerve in the human body, the vagus contributes to the innervation of the viscera, including the heart. Measures of cardiac vagal function like RSA have been used as a proxy for the parasympathetic…

rhythmic electrical impulses to relax and contract the muscles.” (Lerner and Lerner, 2014). If the does not work and you have a irregular heartbeat you may need a pacemaker. This will help control the irregular heartbeats with low energy shocks to the SA node or…