● `color{brown}("Erythrocytes, leucocytes")` and `color{brown}("platelets")` are collectively called `color{brown}("formed elements")` and they constitute nearly 45 % of the blood.
`star` `color{green}("Erythrocytes:")`
● `color{brown}("Erythrocytes")` or red blood cells (RBC) are the most abundant of all the `color{violet}("cells in blood.")`
● A healthy adult man has, on an average, `color{violet}("5 millions to 5.5 millions of RBCs")` `mm^(–3)` of blood.
● `color{violet}("RBCs")` are formed in the `color{brown}("red bone marrow")` in the adults.
● RBCs are devoid of `color{violet}("nucleus")` in most of the `color{violet}("mammals")` and are `color{violet}("biconcave")` in shape.
● They have a red coloured, iron containing complex protein called `color{brown}("haemoglobin,")` hence the colour and name of these `color{violet}("cells.")`
● A healthy individual has `color{violet}("12-16 gms of haemoglobi")`n in every 100 ml of blood.
● These `color{violet}("molecules")` play a significant role in transport of `color{violet}("respiratory gases.")`
● RBCs have an average life span of 120 days after which they are `color{violet}("destroyed")` in the `color{brown}("spleen (graveyard of RBCs)")`.
`star` `color{brown}("Leucocytes:")`
● `color{brown}("Leucocytes")` are also known as `color{brown}("white blood cells (WBC)")` as they are colourless due to the lack of `color{violet}("haemoglobin.")`
● They are `color{violet}("nucleated")` and are relatively lesser in number which averages `color{violet}(6000-8000 mm^(–3))` of blood.
● `color{violet}("Leucocytes")` are generally short lived.
● We have two main categories of WBCs – `color{brown}("granulocytes and agranulocytes")`.
● `color{brown}("Neutrophils, eosinophils and basophils")` are different types of granulocytes, while `color{violet}("lymphocytes and monocytes")` are the agranulocytes.
● `color{violet}("Neutrophils")` are the most abundant cells (60-65 %) of the total WBCs and basophils are the least (0.5-1 %) among them.
● `color{violet}("Neutrophils and monocytes")` (6-8 %) are `color{brown}("phagocytic cells")` which destroy foreign organisms entering the body.
● `color{violet}("Basophils")` secrete `color{brown}("histamine, serotonin, heparin,")` etc., and are involved in inflammatory reactions.
● `color{violet}("Eosinophils")` (2-3 %) resist infections and are also associated with `color{brown}("allergic reactions")`.
● `color{violet}("Lymphocytes")` (20-25 %) are of two major types – `color{brown}("‘B’")` and `color{brown}("‘T’")` forms.
● Both `color{violet}(B)` and `color{violet}(T "lymphocytes")` are responsible for immune responses of the body.
`star` `color{green}("Thrombocytes")`
● Platelets also called `color{brown}("thrombocytes")`, are cell fragments produced from `color{brown}("megakaryocytes")` (special cells in the `color{violet}("bone marrow")` ).
● `color{violet}("Blood normally")` contains 1,500,00-3,500,00 platelets `color{violet}(mm^(–3))`.
● Platelets can release a variety of substances most of which are involved in the coagulation or `color{violet}("clotting of
blood")`.
● A reduction in their number can lead to `color{violet}("clotting disorders")` which will lead to excessive loss of `color{violet}("blood")` from the `color{violet}("body.")`
● `color{brown}("Erythrocytes, leucocytes")` and `color{brown}("platelets")` are collectively called `color{brown}("formed elements")` and they constitute nearly 45 % of the blood.
`star` `color{green}("Erythrocytes:")`
● `color{brown}("Erythrocytes")` or red blood cells (RBC) are the most abundant of all the `color{violet}("cells in blood.")`
● A healthy adult man has, on an average, `color{violet}("5 millions to 5.5 millions of RBCs")` `mm^(–3)` of blood.
● `color{violet}("RBCs")` are formed in the `color{brown}("red bone marrow")` in the adults.
● RBCs are devoid of `color{violet}("nucleus")` in most of the `color{violet}("mammals")` and are `color{violet}("biconcave")` in shape.
● They have a red coloured, iron containing complex protein called `color{brown}("haemoglobin,")` hence the colour and name of these `color{violet}("cells.")`
● A healthy individual has `color{violet}("12-16 gms of haemoglobi")`n in every 100 ml of blood.
● These `color{violet}("molecules")` play a significant role in transport of `color{violet}("respiratory gases.")`
● RBCs have an average life span of 120 days after which they are `color{violet}("destroyed")` in the `color{brown}("spleen (graveyard of RBCs)")`.
`star` `color{brown}("Leucocytes:")`
● `color{brown}("Leucocytes")` are also known as `color{brown}("white blood cells (WBC)")` as they are colourless due to the lack of `color{violet}("haemoglobin.")`
● They are `color{violet}("nucleated")` and are relatively lesser in number which averages `color{violet}(6000-8000 mm^(–3))` of blood.
● `color{violet}("Leucocytes")` are generally short lived.
● We have two main categories of WBCs – `color{brown}("granulocytes and agranulocytes")`.
● `color{brown}("Neutrophils, eosinophils and basophils")` are different types of granulocytes, while `color{violet}("lymphocytes and monocytes")` are the agranulocytes.
● `color{violet}("Neutrophils")` are the most abundant cells (60-65 %) of the total WBCs and basophils are the least (0.5-1 %) among them.
● `color{violet}("Neutrophils and monocytes")` (6-8 %) are `color{brown}("phagocytic cells")` which destroy foreign organisms entering the body.
● `color{violet}("Basophils")` secrete `color{brown}("histamine, serotonin, heparin,")` etc., and are involved in inflammatory reactions.
● `color{violet}("Eosinophils")` (2-3 %) resist infections and are also associated with `color{brown}("allergic reactions")`.
● `color{violet}("Lymphocytes")` (20-25 %) are of two major types – `color{brown}("‘B’")` and `color{brown}("‘T’")` forms.
● Both `color{violet}(B)` and `color{violet}(T "lymphocytes")` are responsible for immune responses of the body.
`star` `color{green}("Thrombocytes")`
● Platelets also called `color{brown}("thrombocytes")`, are cell fragments produced from `color{brown}("megakaryocytes")` (special cells in the `color{violet}("bone marrow")` ).
● `color{violet}("Blood normally")` contains 1,500,00-3,500,00 platelets `color{violet}(mm^(–3))`.
● Platelets can release a variety of substances most of which are involved in the coagulation or `color{violet}("clotting of
blood")`.
● A reduction in their number can lead to `color{violet}("clotting disorders")` which will lead to excessive loss of `color{violet}("blood")` from the `color{violet}("body.")`