Question 1

Question 2Explain the process of blood circulation in the body with the help of a schematic diagram.

Accepted Answer

For completing one round of circulation in the body, the blood passes twice through the heart. This is called double circulation. Double circulation involves two processes: pulmonary circulation and systemic circulation.Pulmonary circulation — The circulation of blood between the heart and lungs is called pulmonary circulation. From the right auricle, the blood flows into the right ventricle and then to the lungs through the pulmonary arteries. The oxygenated or pure blood from the lungs is brought to the left auricle by the pulmonary veins.Systemic circulation — The circulation of blood between the heart and other body organs is called systemic circulation. From the left auricle, the oxygenated blood flows into the left ventricle and from there it is pumped into the aorta, the largest artery in the body. The aorta divides further to supply blood to all body tissues.Below schematic diagram shows circulation of blood in the body:

Question 2

Question 3Why is a person with blood group O called a universal donor and a person with blood group AB called a universal recipient?

Accepted Answer

A person with blood group O is called a universal donor since his blood can be given to a person with any blood group. As blood group O has neither antigen A nor B so it doesn't cause self-clumping with any antibodies making it compatible with all blood groups.A person with blood group AB is called a universal recipient since he can receive blood from a person with any blood group. As blood group AB has no antibodies, so there is no attack on the antigens of any blood group making it compatible to receive blood from all blood groups.

Question 3

Question 4What is lymph? How is it different from blood?

Accepted Answer

Lymph is a fluid that contains infection-fighting white blood cells. When blood reaches the capillaries, some of the water and dissolved solutes are filtered out from the plasma into tissue spaces to form a tissue fluid called lymph. Some of this lymph enters tiny channels called lymph vessels.Difference between Blood and Lymph — Basically, lymph has all the elements of blood except RBCs and blood platelets. It is slightly yellowish in colour and contains special type of white blood cells called lymphocytes.

Question 4

Question 5List the functions of the lymph.

Accepted Answer

Following are the functions of lymph:Transportation — The lymph helps in transporting nutrients and hormones to the body cells. It also removes waste materials from the body cells to the tissues and finally pours them into veins. Lymph carries lymphocytes and antibodies from the lymph nodes to the blood. The lymph also absorbs and transports fats (fatty acids and glycerol) from the small intestine to the blood.Defence — Lymph carries lymphocytes and antibodies, which destroy the harmful microorganisms and foreign particles in the lymph nodes. Lymph takes the bacteria entering the body to the lymph nodes for destroying them. This prevents the infection from spreading to other tissues.Drainage — The lymph drains excess tissue fluid from the intercellular spaces back into the blood.

Question 5

Question 7Name the four blood groups in human beings. On what basis are they named?

Accepted Answer

The four blood groups in human beings are A, B, AB and O. They are named on the presence or absence of specific antigens.

Question 6

Question 6Blood transfusion

Accepted Answer

Blood transfusion — The process by which blood is transferred from one person to another is called blood transfusion.

Question 7

Question 1Given below is a diagram of human heart. Draw it in your notebook and label the following parts.Right auricleLeft Ventricletricuspid valvebicuspid valvepulmonary arterypulmonary veinsinter-ventricular septum

Accepted Answer

The below diagram shows the labelled parts of human heart:

Circulatory System in Humans

Answer the following in detail

Answer the following in short

Define the following terms

Label Diagram of Human Heart