Lymphocytes make up 25-33% of leukocytes
– They are agranulocytes, with no granules
– Their nucleus is round and fills most of the cell
– Some live for days, while others live for years
– They develop from lymphoblasts
▪ Some enter the blood and become lymphocytes
▪ Some mature in bone and become B cells
▪ Some mature in the thymus and become T cells

A lymphocyte has no granules in its cytoplasm, and so it is classified as an agranulocyte.

It has little cytoplasm and a nucleus that is round and has no lobes.

Monocytes

Monocytes make up 3-7% of leukocytes
– They are the largest type of leukocyte
– They are agranulocytes, with few or no granules
– Their nucleus is large and shaped like a kidney bean
– They develop in the red marrow from stem cells and mature in several stages

A monocyte has few or no granules in its cytoplasm, and so it is classified as an agranulocyte.

It has a large amount of cytoplasm and a nucleus that is large and shaped like a kidney bean.