Basophils are a type of granulocytes, which are in turn a type of leucocytes (i.e. white blood cells).
Granulocytes, including basophils, are distinguished from the other category of leucocytes - which are called agranulocytes, because granulocytes contain chemical-filled cytoplasmic vesicles called granules.
- 0.5 - 1% of all white blood cells are basophils.
- are 8-10 um in diameter
- have nuclei that have 2 lobes, and
- have large cytoplasmic granules that appear deep blue - purple in colour.
An increased, that is a higher proportion than usual, of basophils in the blood may indicate an inflammatory condition somewhere in the body.
The functions of basophils include the liberation of heparin, histamine, and seratonin in allergic reactions.
For more information about other components (sometimes called the 'constituents') of blood, see the page about the structure and functions of blood. This may interest students of holistic massage, reflexology, beauty therapies, or health-related courses.