Platelet

 Platelet/Thrombocytex

Platelets is called thrombocytes.

Thrombus means "clot", Cyte means "cells"

Platelets count; 25,0000-400000/mm3 of blood, more numerous than leukocytes.

Shape and size; Platelets are very small non-nucleated discs and are about one quarter the size of the RBCs (2-4 micrometer in dimeter).

Platelets exhibit many granules. As they have no nucleus so they are incapable of cell division.

Platelets help body from clots to stop bleeding. If blood vessels get damaged, it sends out signals that are picked by platelets. 

Platelets then rush to the site of damage and form a plug, or clot, to repair the damage.

Function of Platelets

Main function of platelets is to prevent blood loss.

1. Repaire of injured blood vessels

2. Forming platelet plug, contribute fibrin formation, seal holes in blood vessel

3. To forming clot

4. Defense mechanism

Forming Platelet Plug

Platelet plug seal holes in small vessels, help to repair slightly damaged blood vessels

After entering blood stream, platelets begin to pick up and store chemical substance that can be released later to help seal blood vessel break.

Formation of Clot

Forming clot is maain function of platelets is to start process of blood clotting.

Granules contain chemicals that release to promote blood clotting.

Platelet contain variety of substance, including-

1. Platelet factors lll and lV

2. Serotonin

3. Platelet fibrinogen

4. Adenosine triphosphate (ATP)

Activated and initiate clotting mechanism.