Question

Diagram and briefly describe structures and functions of lymphoid organs. Include both types of the organs, and the immune processes that take place inside.

Answer 1

The human immune system consist of lymphoid organs ,tissues,cells,and soluble molecules like antibodies.

Lymphoid organs are the organs where origin and/or maturation and proliferation of lymphocytes occur.that can be classified into primary lymphoid organs and secondary lymphoid organs.

The primary lymphoid organs are bone marrow and thymus where immature lymphocytes differentiate into antigen sensitive lymphocytes.secondary lymphoid organs include spleen,lymph nodes,tonsils,peyer's patches of small intestine and appendix. after maturation the lymphocytes migrate into secondary lymphoid organs. the secondary lymphoid organs provide the sites for interaction of lymphocytes with the antigen,which then proliferate to become effector cells.

BONE MARROW

Bone marrow is the main lymphatic organ where all blood cells including lymphocytes are produced. it is a soft,gelatinous tissue that fills the medullary cavities, the centers of bones. .the to types of bone marrow are red bone marrow know as myeloid tissue and yellow bone marrow,or fatty tissue.both types of bone marrow enriched with blood vessels and capillaries.bone marrow contain immature cells called stem cells.

function

most red blood cells,platelets, and most of the white blood cells are formed in the red marrow.yellow bone marrow produces fat, cartilage, and bone.it also provide micro environment for the development and maturation of T lymphocytes.the bone marrow also produces and releases more white blood cells in responce to infection,and more platelet in responce to bleeding,if a person experiences serious blood loss,yellow bone marrow can be activated and transformed into red bone marrow. healthy bone marrow is important for arange of systems and activities.

THYMUS

Thymus is a lobed organ pyramid shape located near the heart and breastbone. .the thymus quite large at the time of birth but keeps reducing in size with age and by the time puberty is attained it reduces to a very small size.thymus serves vital role in the training and development of T cells,an extremely important type of white blood cells.T cells defend he body nfrom potentially deadly pathogens such as bacteria ,virus,and fungi.

SPLEEN

The spleen is a large bean shaped organ .it mainly contains lymphocytes and phagocytes, it acts as a filter of the blood by trapping blood-borne micro organisms,spleen also has a large reservoir of erythrocytes.

LYMPH NODES

Lymph nodes are small solid structures located at different point along the lymphatic system.lymph nodes serve to trap the micro organism or other antigens,when happen to get into the lymph and tissue fluid.antigens trapped in the lymph nodes are responsible for the activation of lymphocytes present there and cause the immune response.

TONSILS

Tonsils are the 2 lymph nodes located on each side of the back of throat,their function is deffence mechanism and help prevent body from getting an infection.when tonsils become infected the condition called tonsilitis.