societal influence Essay

Early doctors were researching arrhythmia in heart beat as a result of unknown abnormal neuro-cardio mechanisms of the heart, one of theories was that SA and AV nodes were interfering with each other’s bio-electrical impulses another theory was that the right side of the septum was hypersensitive to electrical impulse, all were more else on the right track because we know now that SVT is a result of a faulty electrical connections of the heart.

5. Conduction, pp.1099-1103. Conduction system of the heart. Specialized cardiac muscle cells in the wall of the heart rapidly conduct an electrical impulse throughout the myocardium. The signal is initiated by the SA node (pacemaker) and spreads to the rest of the atrial myocardium and to the AV node. The AV node then initiates a signal that is conducted throught the ventricular myocardium by way of the AV bundle (of His) and Purkinje fibers.

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

The atria and ventricles are separated by valves known as the AV valves. The purpose of these valves is to prevent blood from flowing in the wrong direction. Following the movement of blood from the atrium, into the ventricle, the AV valve snaps shut which causes the first heart sound of the heart beat. The beat is caused by the closing of two other valves.

of atria and ventricle. Impulses not being transmitted from atria to the ventricle; no whole number relationship between atrial and ventricular contractions was demonstrated.

Moreover, atrial stimulation close to the AV BT insertion site results in maximal preexcitation. Failure of atrial stimulation to increase the amount of preexcitation can occur because of markedly enhanced AVN conduction, the presence of another AV BT, or pacing-induced block in the AV BT due to the long ERP of the BT (Kuo et al, 1996).

Atrioventricular (AV) node: the area of the heart conduction system responsible for receiving impulses from the SA node via intermodal pathways and stimulate the ventricles to contract

“An electrical signal from the ventricles causes an early heart beat that generally goes unnoticed”

Cardiac suction- during ventricular systole, the teninous cords pull the Av valve cusps downward, slightly expanding the atrial space. This creates a slight suction that draws blood into the atria and pulmonary veins.

Cardiac muscle: contracts in response to signals from the cardiac conduction system to make the heartbeat.

Regular electrical impulses are sent within the conduction system of the heart prompting contraction (Marieb, 2015). These electrical signals can be identified and documented by the use of an electrocardiography (ECG) machine. In a familiar ECG recording, three waves will occur; The P wave, QRS complex and

This allows your cardiovascular centres in your brain a little bit more latitude as far as controlling your heart rate. If you were to remove a beating heart from someone's body you would find that the heart is no longer being suppressed by the parasympathetic nervous system and it will accelerate to the same pace as the sinoatrial node. The SA node generates action potentials approximately 100 times per minute due to the physiology of the heart, its own permeability to sodium and calcium via its channels, and a host of other things. Anywhere between 80 to 100 beats per minute is normal for the SA node.

I know that the SA node fires the start of the EKG, so it must happens somewhere before the P-wave and the AV node is the one that ends the start, which means that it must occur after the P-wave.

The Sinus node which are located in the upper right chamber of the heart sends an electrical signal which travels through the right and the left atria. The electrical signals traveling causes the atria to contract which helps move the blood into the ventricles, lower chambers of the heart. The signals traveling through the atria is recorded as the P wave. The atrioventricular node is a group of cells between the atria and ventricles where the electrical signals pass through slowly which allows the ventricles to fill with blood. The signals then leaves the atrioventricular node and travels a pathway which is known as the bundle of His. From the bundle of His the signals travel into the right and left bundle branches. The electrical signals spread

In the beginning of the electrophysiology of the heart, it is taught that the heart is contracted by a combination of generating and propagating action potentials. I have learned that action potentials are electrical impulses that travel across the cell membranes in the heart. These action potentials are one of many things that determines if the heart functions and quite frankly if you live or not. According to Baylor Heart and Vascular Hospital, these contractions are what triggers the events of an action potential which are also identical in skeletal muscles, cardiac muscle, and neurons. To not get confused with the “triggering effect”, but a transmitted action potential is technically called a nerve impulse. An action potential isn’t always in a constant state of actively moving around, the “resting stage” or resting membrane potential as it should be referred to, is the electrical difference between both electrolytes from the inside of the cell membrane