Transportation in Animals and Plants

The parts involved in excretion form the excretory system.

The process of removal of wastes produced in the cells of the living organisms is called excretion.

The English physician, William Harvey (A.D.1578–1657), discovered the circulation of blood. The current opinion in those days was that blood oscillates in the vessels of the body. For his views, Harvey was ridiculed and was called “circulator”. He lost most of his patients. However, before he died, Harvey’s idea about circulation was generally accepted asa …

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A doctor uses the stethoscope as a device to amplify the sound of the heart.

The walls of the chambers of the heart are made up of muscles. These muscles contract and relax rhythmically. Thisrhythmic contraction followed by its relaxation constitute a heart beat.

The heart is an organ which beats continuously to act as a pump for the transport of blood.The heart is located in the chest cavity with its lower tip slightly tilted towards the left . Heart like fist. Your heart is roughly the size of your fist. the heart has four chambers. The two upper …

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Hundreds of people die due to unavailability of blood. Voluntary blood donation is harmless and painless and can save precious lives. Blood can be donated at hospitals and other places authorised by the government. Donated blood are stored with special care in Blood Banks.

On reaching the tissues, Arteries and Vein divide further into extremely thin tubes called capillaries. The capillaries join to form veins which empty into the heart.

Veins are the vessels which carry carbon dioxide-rich blood from all parts of the body back to the heart. The veins have thin walls. There are valves present in veins which allow blood to flow only towards the heart.

The number of beats per minute is called the pulse rate. A resting person, usually has a pulse rate between 72 and 80 beats per minute