Comparison of Lymphoctes involved in the Immune response.

THE LYMPHATIC SYSTEM

By : Khairul Anwar Bin Abu Mansor

       Faculty of Applied Science, Universiti Teknologi MARA Malaysia

AN OVERVIEW OF THE LYMPHATIC SYSTEM

1.       Lymphocytes respond to the presence of

-          Invading pathogens (bacteria and fungus)

-          Abnormal body cells, (virus infected cells or cancel cells)

-          Foreign proteins (such as the toxins released by some bacteria.

2.       The barrier are specific defenses known as immune response.

ORGANIZATION OF THE LYMPHATIC SYSTEM

The lymphatic system consists of the following

1.       A network of lymphatic vessels – a.k.a lymphatics, which begin in peripheral tissues and end at connections to veins.

2.       Lymph – a fluid that resembles plasma but contains a much lower concentration of suspended protein

3.       Lymphoid organs – which are connected to lymphatic vessels and contain large number of lymphocytes.

FUNCTIONS OF THE LYMPHATIC SYSTEM

The primary functions of the lymphatic system

1.       The production, maintenance, and distributions of lymphocytes. Lymphocytes are produced and stored with in

-          Lymphoid tissues and organs, such as the spleen and thymus

-          Areas of red bone marrow.

2.       The return of fluid and solutes from peripheral tissues to the blood. Capillaries normally deliver more fluid to the tissues than they carry away.  The return of tissues fluids through the lymphatic vassels maintains normal blood volume and elimates local variations in the composition of the interstitial fluid.

3.       The distribution of hormones, nutrients and waste products from their tissues of origin to the general circulation. Substance that originate in the tissues but are for some reason unable to enter the bloodstream directly may do so by way of the lymphatic vessels.

LYMPHATIC VESSELS

Lymphatic vessels carry lymph from peripheral tissues to the venous system. The smallest lymphatic vessels are called lymphatic capillaries.

LYMPHOCYTES.

1.       Lymphocytes account for 20-30 percent of the circulating white blood cell population.

2.       The body contains some 10¹² lymphocytes with a combined weight of over a kilogram.

Types of lymphocytes.

1.       3 classes of lymphocytes are in blood

i.         T-Cells (thymus cells

ii.       B-Cells (Bone marrow derived)

iii.      NK Cells (natural killer)

2.       Each type has distinctive biochemical and functional characteristics T-Cells.

3.       T Cells - 80% of circulating lymphocytes are classified as T cells. Many types of T cells exist, including the following

i.         Cytotoxic T cells – attack the foreign cells orbody cells infected by viruses. Their attack commonly involves direct contact. These lymphocytes are the primary cells involved in the production of cell-mediated immunity or cellular immunity

ii.       Helper T cells – which stimulate the activation and function of both T cells and B cells.

iii.      Suppressor T cells – inhibits the activation and function both T cells and B cells.

4.       B Cells account for 10-15% of circulating lymphocytes. When stimulate, B cells can differentiate into plasma cells. Plasma cells are responsible for the production and secretion of antibodies, soluble proteins that are also known as immunoglobulin. These proteins bind to specific chemical targets called antigens.  Most antigens are pathogens, parts or products of pathiogens, or other foreign compounds. Most antigens are proteins, but some lipids, polysaccharides and n.acids can also stimulate antibody productions. B cells are responsible or antibody-mediated immunity, which is also known as humoral immunity because antibodies occur in body fluid.

5.       NK Cells – Remaining 5 – 10% of circulating lymphocytes. a.k.a large granular lymphocytes. It’s attack foreign cells, normal cells infected with viruses, and cancer cells that appear in normal tissues.

* To Be continued

Immune system is the one that very important in for our body. Without immune system, we always feel sick everytimes. Because we always expose to surrounding area that have lots of microorganisms such as bicteria and viruses.

So, why why study immunology?

Immunology is the study of how the immune system or the body defense system protects the body defense system protect the body from invading foreign substances and provide the body with immunity

The function of the immunity is to defence the individual against the foreign substances expecially the harmfull microorganisms  or their product. Thus the immune system will give us protection or immunity. It’s also function to protect the body to some tumors and rejection of transplant.

The action of immune system is:

-          Preventing microorganisms from entering the body

-          Removing if they (microorganisms) manage to get in.

-          Destroy if they (microorganism) manage to cause disease.

The mechanisms involving recognition and disposal foreign susbstances from enter the body (complex)

they is two body defense system.

-          Non-specific also known as innate immunity

-          Specific immune system also name adaptive immune system.