Cardiac Cycle Is The Sequence Of Events That Occurs When The Heart Beats

There are two major cycles in the heart the systemic loop and the pulmonary loop. The systemic loop begins with oxygen rich blood coming from the lungs enters the upper left chamber of the heart. As the blood flows through the entire heart the blood then begins the journey through

Both the right and left atrium contract causing blood to flow though the two valves, and then into the left ventricle. The left ventricle pumps blood into the systemic circulation through the aorta. This systemic circulation system is much bigger than the pulmonary circulation system, which is why the left ventricle is so big. The blood on the left side of the heart is oxygenated. It becomes oxygenated when the deoxygenated blood passes through the right atrium and then flows into the left ventricle. It is then pumped along the pulmonary artery into the lungs where it is oxygenated. It then travels through the pulmonary veins back into the heart. It enters through the left atrium and then travels to the left ventricle. This process is repeated over and over again, to make blood continuously flow through the heart, lungs and body. This process ensures that there is always enough oxygen for the body to work

Left ventricle pumps the blood into the aorta, where the blood is supplied to the body tissues by the systemic arteries.

In a normal human being the heart correctly functions by the blood first entering through the right atrium from the superior and inferior vena cava. This blood flow continues through the right atrioventricular valve into the right ventricle. The right ventricle contracts forcing the pulmonary valve to open leading blood flow through the pulmonary valve and into the pulmonary trunk. Blood is then distributed from the right and left pulmonary arteries to the lungs, where carbon dioxide is unloaded and oxygen is loaded into the blood. The blood is returned from the lungs to the left

When the left atrium is filled with blood, the heart contracts and the blood passes through the bicuspid valve and into the left ventricle.

Blood then travels out toward the lungs for oxygenation via the pulmonary artery and returns to the heart through the pulmonary veins entering the left atrium. It is pumped through the mitral valve into the left ventricle to exit the aortic valve to the circulation via the aorta. The questions asked in the lab packet directly related to the anatomy and physiology of the heart which allowed to understand how the heart works as a

In the normal conduction of the heart the electrical impulse starts in the SA node, also called the pacemaker of the heart. The electrical impulse travels through the right atrium and through the Bachmann’s bundle into the left atrium. This stimulates the atria to contract. Next the signal travel to the AV node. The AV node slightly delays the signal. This delay is needed for the heart to beat properly. Without this delay the atria and ventricles would beat at the same time. The electrical signal then travels to the Bundle of His where it is split into the signals going to the right and left ventricle. The signal

Meaning The Sa node and Av node work together, forcing blood into the ventricles, which contract, forcing the blood to leave from the left side of the heart. The blood that enters the right side of the heart enters through veins as it is under less pressure. Blood with co2 in it will exit the right side of the heart through the pulmonary artery to the lungs where gaseous exchange occurs.

The Q is the first wave downward, or negative, wave form of the QRS complex. The R wave is the first positive or upward, deflection. The R wave can occur with or without a Q wave. The T wave represents ventricular repolarization. The QT indicated the time from ventricular depolarization to repolarization. The wave of electricity it continues traveling through the myocardium to atrioventricular node. The AV node it coordinates the incoming electrical impulses from the atria and relays the impulse to the ventricles through a bundle of specialized muscle fibers. The atria pump blood into the ventricles and then the ventricles pump blood out of the heart. Chambers of the heart fill with blood during a relaxation phase diastole and eject blood during a contraction phase systole. Atrial

Every beat you feel you heart make is one complete cycle of blood entering the heart and exiting the heart. The heart cycle breaks down into two main contractions. Atrial contraction of the heart forces blood from the vena cava and the pulmonary veins through the atrioventricular valves and into the left and right ventricles. During ventricular contraction the tricuspid and mitral valves close and the blood is forced out of the ventricles through the semilunar valves into the aortic and pulmonic arteries. The pulmonic arteries supply blood to the lungs for oxygenation while the aortic arteries circulate the already oxygenated blood from the lungs, to the rest of the body. Diastole is the period of relaxation when the blood fills the ventricles. Systole is the period of contraction that forces the blood out of the ventricles.

The heart is divided into four chambers. The top two chambers are the atria and the bottom two chambers are the ventricles. Two of the chambers, together make up the right heart and pump blood to your lungs, where it picks up oxygen. Blood that is carrying oxygen then travels to the two chambers on the left side of your heart, which then pumps the blood to the rest of your body. The ventricles (the bottom chambers) are powerful pumping chambers, which push the blood out of the heart when they contract. The smaller and less powerful top chambers of the heart (the atria), help to fill the ventricles with blood for the next contraction. The regulation and coordinated pumping action of the heart is provided by a network of electrical connections, which deliver electrical signals to the heart

The heart is able to do this thanks to the specialized cardiac muscle it contains. The contraction of the heart displays excitatory- contraction coupling (EC coupling) similar to skeletal muscles except the action potential in the heart originates spontaneously at the peace maker of the heart (Silverthorn, 2013). Contraction happens when a rapid depolarization occurs due to the influx and opening of sodium voltage gated channels to raise the membrane potential toward the threshold value causing a firing of action potential. The conduction and cardiac cycle starts at a resting distol state for both ventricles and atriums and is initiated with the depolarization at the SA node (Silverthorn, 2013). This causes an action potential which moves rapidly towards the AV node where the signal gets slowed down (Silverthorn, 2013).When the signal reaches this point it causes a contraction/systole stage of the right and left atriums. This causes blood to be pumped into the ventricles through the AV valves (Silverthorn, 2013). The action potential then travels to the ventricles down the bundle branches out towards the Purkinje fibers (Silverthorn, 2013). In terms of the cardiac cycle an isovolumetric contraction occurs during the pause of the signal at the AV node allowing the AV valves to close, followed by ventricular systole where the ventricles expel blood into circulation (Silverthorn, 2013). The final stage in the cardiac cycle occurs between stimulations of action potential when the ventricles and atriums are in diastole and the chambers fill with blood once again (Silverthorn,

The cardiac cycle is the sequence of steps that are carried out when the heart beats. There are two main phases of the cardiac cycle; the diastolic phase and the systole phase. The diastole phase causes the heart to fill with blood and the systole phase moves the blood from the heart to the arteries. One cardiac cycle is completed when the heart fills with blood and then is pumped back out of the heart. The two main phases can be broken down into four steps.

The heart goes through an auto rhythmic cycle that starts and ends in the heart. The process can be broken down 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 heart functioning for a limited time.[5] Once the single reaches there, the atria contract and allows the blood to drop to the ventricles. The signal then travels to the Atrioventricular Bundle where it contracts the ventricles. The atrioventricular

The cardiac cycle can be subdivided into two major phases, the systolic phase and the diastolic phase. Systole occurs when the ventricles of the heart contract. Accordingly, systole results in the highest pressures within the systemic and pulmonary circulatory systems. Diastole is the period between ventricular contractions when the right and left ventricles relax and fill.