Question

what is blood. describe its structure.​

Answer 1

Answer:

Blood is a red coloured liquid present in our body it have no structure

Answer 2

$\large\underline{ \red{ \sf \pmb \: Blood }}$

$\longrightarrow$ Blood is a fluid connective tissue that circulates constantly around the body, allowing constant communication between tissues distant from each other.

$\longrightarrow$ Blood is composed of a clear, straw-coloured, watery fluid called plasma in which several different types of blood cells are suspended.

$\longrightarrow$ Plasma contains water (90-92%) and other disolved and suspended substances like plasma proteins, inorganic salts, nutrients, waste materials, hormones and gases.

There are three types of formed elements (blood cells) in blood:

1) Erythrocytes (red cells)

2) Leukocytes (white cells)

3) Platelets (thrombocytes)

Erythrocytes(RBC)

$\longrightarrow$ Most abundant type of blood cells.

$\longrightarrow$ Their main function is transport of respiratory gases, mainly oxygen, but they also carry some carbon dioxide.

$\longrightarrow$ They also maintain the viscosity and pH of blood.

Leukocytes (WBC)

$\longrightarrow$ These cells have an importnat function in defence and immunity.

$\longrightarrow$ They detect foreign or abnormal (antigenic) material and destroy it, through a range of defence mechanisms.

There are two main types:

(a) Granulocytes (polymorphonuclear leukocytes)- neutrophils, eosinophils and basophils.

(b) Agranulocytes - monocytes and lymphocytes.

Platelets (Thrombocytes)

$\longrightarrow$ These are very small discs, 2-4 micrometer in diameter.

$\longrightarrow$ They are responsible for coagulation or clotting of blood.

Functions of blood:

• Transport of - gases, nutrients, waste products, processed molecules, regulatory molecules, blood cells, plasma proteins, hormones and enzymes

• Regulation of pH and osmosis

• Maintenance of body temperature

• Protection against foreign substances

• Clot formation