Question

What is the composition of blood?

Answer 1

Hint: Blood is a fluid in our body. It is thicker than water. It oozes out when we get a wound. It provides nutrition to the body. Our heart pumps the oxygenated blood to the body via arteries. Veins carry the deoxygenated blood. It also carries haemoglobin which gives the blood the red colour.

Complete answer:
Blood is fluid in the body. It has four components-plasma, red blood cells, white blood cells and platelets. It has the function of transporting oxygen and nutrients throughout the body. The blood flows through veins, arteries and capillaries. It has about 55 % plasma and 45% blood cells.
The plasma-The liquid component of blood is plasma. It has water, fat, salts and proteins. Its main function is to transport antibodies, chemical messengers, clotting proteins etc, to the body to maintain the fluid balance.
Red blood cells- They are red making 40-45% of the body cell. Erythropoietin produces the RBCs. They are produced as immature cells in the bone marrow. It takes almost 7 days for their maturation. They lack a nucleus and can change their shape.
White blood cells- They protect the body from infection. They make 1-2% of the blood cell. They are the immediate response cells. Neutrophils and Lymphocytes are the major WBCs. T lymphocytes help to regulate the immune cells. B lymphocytes make antibodies which target bacteria, viruses etc.
Platelets- They are not cells but small fragments of the cell. They participate in the blood clotting process. They gather at the site of the injury. Their higher amount can cause clotting which will lead to a stroke. Antiplatelet therapy will recover this condition.

Note: Hematopoiesis is the process of regulating the blood cells from the stem cells. Blood cells are also found in the umbilical cord of the newborn. Blood regulates the temperature of the body. They bring waste products to the kidneys to filter out the blood.