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Electrocardiogram Examination

By: Administrator, Views: 10565

An electrocardiogram (ECG or EKG) is a test that checks how your heart is functioning by measuring the electrical activity of the heart. With each heartbeat, an electrical impulse (or wave) travels through your heart. This wave causes the muscle to squeeze and pump blood from the heart. Sinoat...

Cardiac conductile cells

By: HWC, Views: 7969

• In order for the heart to function properly, all of its cells must contract in a specific sequence. This sequence is determined by a pathway known as the conduction system. • Cardiac muscle cells have two attributes that enable the conduction system to work: • Connective. Action pot...

Heart sounds

By: HWC, Views: 7605

During a normal, healthy heartbeat, or what we call a cardiac cycle, the top two chambers of the heart, called the atria, contract simultaneously. Then, as they relax, the bottom two chambers, called the ventricles, contract. This explains what happens during a cardiac cycle, but what it doesn't ...

Electrical Conduction System of the Heart

By: HWC, Views: 6679

Your heart is a muscle that works continuously, much like a pump. Each beat of your heart is set in motion by an electrical signal from within your heart muscle. The electrical activity is recorded by an electrocardiogram. known as an EKG or ECG. Each beat of your heart begins with an electric...

Interpreting a cladogram Animation

By: HWC, Views: 1376

Using a cladogram to determine relative relatedness and whether the lungfish is more closely related to a human or to a trout. To determine the relative relatedness, we begin by tracing the branches from the human and the lungfish to the point where they meet. We'll call this node 1. Now...

Coaductile pathway, Timing of contraction signal & Conduction system and ECG

By: HWC, Views: 7925

• When the system is healthy, the signal to contract the entire conduction system originates in the SA node - known as the heart's pacemaker. • The SA node triggers contraction because it depolarizes at a faster rate than other parts of the conduction system. • The wave of excitation fr...

Depolarization of the SA node, Action potentials of the myocardium & ANS effects

By: HWC, Views: 7626

• A typical contractile cell in the myocardium has a resting membrane potential. • The resting membrane potential of cells in the SA node is not fixed, and is known as the pacemaker potential. • The action potential of a healthy SA nodal cell has three parts: • Pacemaker potential: ...

Five phases of cardiac cycle & Atrial contraction

By: HWC, Views: 7759

1. Atrial contraction (atrial systole). 2. Isovolumetric (ventricular) contraction. 3. Ventricular ejection. 4. Isovolumetric (ventricular) relaxation. 5. Passive ventricular filling. Beginning of cardiac cycle • Prior to atrial contraction: • Atria and ventricles are relaxed....

Blood Flow through the Human Heart

By: HWC, Views: 7487

The heart is the pump of the human circulatory system. The left side of the heart has two connected chambers, the left atrium and the left ventricle. The right side of the heart also has two connected chambers, the right atrium and the right ventricle. These two sides, or pumps, of the heart are ...