Question

Describe the salient features and functions of one cell from each of the major hematopoetic lineages

Answer 1

Hematopoietic Stem Cells: The white blood cells are particularly responsible for providing specific as well as non-specific immunity. White blood cells are also known as leukocytes. Leukocytes arise from hematopoietic stem cells which are multipotent in nature,

Hematopoeitc stem cells differentiate into two different lineages in a process known as hematopoiesis. The two lineages are lymphoid lineage and myeloid lineage. A lymphoid progenitor cell gives rise to B cells, T cells and natural killer cells, whereas a myeloid progenitor cell gives rise to red blood cells, white blood cells (neutrophils, eosinophils, basophils, monocytes, etc.) and platelets.

One example each of cells from these two lineages are given below:

1. B lymphocytes: These cells arise from lymphoid lineage. A characteristic feature of B cells is their ability to express membrane bound antibodies. After interacting with antigens, these cells differentiate into plasma cells and memory cells. The plasma cells are responsible for secreting antibodies specific to antigens.

Function- B cells are the major players in humoral immunity. By secreting specific antibodies, they help to protect our body against foreign particles.

2. Neutrophils: Neutrophils arise from myeloid lineage. They have a multilobed nucleus and their cytoplasm is granulated. These cells can be stained with both acidic as well as basic dyes.

Function- Neutrophils function as active phagocytic cells. They basically engulf foreign particles and destroy them in the lysosomes, thus providing non-specific immunity to the body.