Biogeochemical cycles can be divided into two broad types:

Local cycles, which involve elements with no atmospheric mechanism for long-distance transfer. Ex- The phosphorus cycle

Global cycles, which involve an interchange between the atmosphere and the ecosystem. Ex- The carbon, Nitrogen, Sulfur, and Water

TLS Online TPP Program

#Id: 4496

#Unit 13. Methods in Biology

In recording limb lead I, the negative terminal of the electrocardiograph is connected to the right arm and the positive terminal is connected to the left arm

TLS Online TPP Program

#Id: 4497

#Unit 13. Methods in Biology

In recording limb lead II, the negative terminal of the electrocardiograph is connected to the right arm and the positive terminal is connected to the left leg.

TLS Online TPP Program

#Id: 4498

#Unit 13. Methods in Biology

To record limb lead III, the negative terminal of the electrocardiograph is connected to the left arm and the positive terminal is connected to the left leg.

TLS Online TPP Program

#Id: 4499

#Unit 13. Methods in Biology

Einthoven’s Law

Lead I potential Lead III potential + = Lead II potential

TLS Online TPP Program

#Id: 4500

#Unit 13. Methods in Biology

Three unipolar limb leads (Augmented limb leads):

VR (right arm), VL (left arm) and VF (left foot).

TLS Online TPP Program

#Id: 4501

#Unit 13. Methods in Biology

In augmented unipolar limb lead, two of the limbs are connected through the negative terminal of the electrocardiograph, and the third limb is connected to the positive terminal.