Phytohormones

In plants nervous system is absent. So, plants control and coordinate their activities by the action of chemical substances called plant hormones or phytohormones present in them. The main phytohormones present in plants are: Auxins Gibberellins Cytokinin Ethylene and...

Lymphatic System

Lymphatic system is a system consisting of lymph, lymphatic capillaries, lymph vessels and lymph nodes. Lymph is another medium of transportation of substances in human body. Lymph is a colourless or light yellow fluid present in tiny tubes called lymph capillaries,...

Electrocardiogram(ECG)

An electrocardiogram is a graphic record of changes in electrical voltage when the heart beats. The machine by which the electrocardiogram is recorded is known as electrocardiograph. The importance of ECG is that it gives us accurate information about the working of...

Double Circulation

In human beings the same blood passes twice through the heart for completing one cycle. Since the blood flows twice through the heart so it is called double circulation. The double circulation has two components. These are: Pulmonary CirculationThe circulation of...

Human Heart

 The human heart is a conical, hollow and muscular organ which helps in pumping blood around all the parts of body. It is covered by a two layered membrane called pericardium. The function of pericardium is to protect heart from shock and mechanical injuries....