The nucleus is large, round, and often shallowly concave
Chromatin is dense and rough
The cytoplasm is basophilic and may contain azurophilic granules. Under an electron microscope, the cytoplasm contains a large number of free ribosomes and lysosomes, rough endoplasmic reticulum, Golgi apparatus, mitochondria, etc.
Produced in bone marrow, lymphoid organs, lymphoid tissue
Participates in immunity and is the main immune cell
Can be divided into small, medium and large lymphocytes. Large lymphocytes do not exist in the blood.