Sequence of cardiac activation, Biology

Sequence of Cardiac Activation

Depolarisation is initiated by an impulse form the SA node. Impulse spreads through both atria. Inter-atrial conduction and atrial myocardial depolarization creates the "P" wave in the cardiac cycle. The normal time taken is 0.08 to 0.12 seconds. The impulse reaches the AV node which delays the impulse about 0.04 to 0.01 seconds. The impulse is transmitted along the branches of the bundle of His to the Purkinje fibers, activating both ventricles almost simultaneously. Activation of ventricular muscle proceeds from apex towards base of heart. The time for a normal ventricular depolarization to occur is 0.06 to 0.10 seconds. PR interval represents the amount of time the electrical impulse takes form the beginning of atrial depolarization to the beginning of ventricular excitation. Normal time is 0.12 o 0.20 seconds. After depolarization, there is ventricular depolarization indicated by the "T" wave in the ECG.

The heart's electrical physiology serves to maintain a coordinated cycle for the electrical depolarization of myocardial fibers that produce chamber filling and emptying.

Posted Date: 10/30/2012 5:56:52 AM | Location : United States

Related Discussions:- Sequence of cardiac activation, Assignment Help, Ask Question on Sequence of cardiac activation, Get Answer, Expert's Help, Sequence of cardiac activation Discussions

Write discussion on Sequence of cardiac activation
Your posts are moderated
Related Questions
What is Left Ventricular Hypertrophy (LVH) ? LVH develops as the response of the heart to chronic pressure or volume overload and is defined as a left ventricular mass exceedin

Q. Explain process of Stress Testing in Women? Estrogen has been implicated as a cause of ST depression. For years it seemed that estrogen protect women from coronary artery di

Is it possible that an X chromosome of a woman can have come from her father? It isn't only possible that an X chromosome of a woman is from her father, it is certain. Each wom

Define Energy Requirements and Dietary Energy Recommendations? Energy requirement, as you may recall studying earlier, is the amount of food energy needed to balance energy exp

Q. Principal categories in classification? First of all there is a need to know what classification is? Let us define in simple term. Classification is placing of a plant (or g

Enzyme-activity Control Availability of the substrate, NADH and nitrate would be an important determinant of the rate of nitrate assimilation. In addition, there are number of

Explain the Composition of Nutrient Agar and Nutrient Broth? The composition and procedure for preparation of some commonly used media, which we will use in the laboratory for

Explain Le Compte Operation-REV Procedure ? This is an alternative type of repair for TGA, VSD and left ventricular outflow obstruction (LVOTQ). In this operation an extrinsic

Osmoregulation in Protozoans Osmoregulation or water balance in protozoa is accomplished by contractile vacuoles. One to several contractile vacuoles may be present within the