Connective Tissue: Types, Function, Examples, Disorders

Connective Tissue: Types, Function, Examples, Disorders

Question 1. Enumerate the cells Present in the Connective Tissue.
Answer.

The cells present in the connective tissue are of two types: fixed and free cells. The fixed cells are long-lived and always remain in the connective tissue, while the free cells are short-lived wandering cells that are continuously replaced by the cells of the blood. The cells of connective tissue are given in the Table.

Types of Connective Tissue Cells

Question 2. Write a short note on lymphocytes.
Answer.

• The lymphocytes are a type of white blood cells (WBCs) that circulate in the blood and are present in large numbers in the lymphatic tissue, such as lymph nodes and spleen.
• Each lymphocyte possesses a large, spherical, dark-staining nucleus, which occupies most of the cell and is surrounded only by a thin rim of cytoplasm.

Types of lymphocytes

The lymphocytes develop from pluripotent stem cells in red bone marrow and then travel through blood into lymphoid tissue where they are activated and become immunocompetent, i.e. they respond to antigens.

Although lymphocytes originate from one source functionally they are differentiated into two main types – B lymphocytes and T lymphocytes.

B lymphocytes: They are short-lived. They are activated by an antigen. When activated by an antigen, they undergo active division and differentiate to form plasma cells. The plasma cells synthesize antibodies against antigens to destroy them. They are short-lived and responsible for antibody-mediated (humoral) immunity.

T lymphocytes: They are activated in the thymus and become immunocompetent. They are long-lived and are responsible for cell-mediated immunity.