Lymphatic System

LYMPHATIC SYSTEM

Introduction

According on the book Gray 's anatomy , lymph is a clear watery , fluid contained in a system of vessels almost as passive as those for the blood . The lymph is then finally emptied into the blood stream by special communications at the junctions of the jugular and subclavian veins at both sides of the neck without communicating to the blood vessels . The lymphatic system consists of the following (1 ) an extensive capillary network which collects lymph in the various organs and tissues (2 ) it is an elaborate system

of collecting vessels which carry the lymph from the lymphatic capillaries to the blood stream opening into the great veins at the root of the neck (3 ) a number of firm rounded bodies called lymph nodes which are placed like filters in the paths of the collecting vessels (4 ) certain lymphatic organs which resemble the lymph nodes , that is , tonsils and solitary or aggregated lymphatic nodules (5 ) the spleen and (6 ) the thymus (Gray , 735

Another book entitled Essentials of human anatomy and physiology , they indicated that the lymphatic system actually consists of two semi-independent parts (1 ) a meandering network of lymphatic vessels and (2 ) various lymphoid tissues and organs scattered throughout the body . The function of the lymphatic vessels is to pick up the excess tissue fluid now called lymph or clear water and return it to the blood steam . The lymphatic vessels also called as lymphatics , form a one way system , and lymph flows only toward the heart . Lymph is transported from the lymph capillaries through successively larger lymphatic vessels referred to as lymphatic collecting vessels , until it is finally returned to the venous system through one of the two large ducts in the thoracic region . Lymphatic vessels are thin-walled , and the larger ones have valves , is a low pressure but pumpless system (Marieb , 368-369

Body

Lymph nodes and other lympoid organs

In the named Life Science , lymph nodes are clusters of pea-sized structures at the intervals of lymphatic system . These nodes acts as a sieves that filters out and destroys bacteria , toxins and dead cells that are removed from the tissues by the lymph . Each node has a fibrous outer covering enclosing a mass of material called lymphoid tissue that contains defensive white blood cells called macrophages that break down foreign particles (Cavendish , 483

There are many lymphoid organs in our body and lymph nodes is just one of an example of many types of it . And in the book Teaching health science : elementary and middle school identified four . Tonsils , found just beneath the epithelium of the mouth and throat , and include the palatine , pharyngeal and lingual tonsils . Second is the thymus , this gland is usually comprised of two lobes , and plays a key role in the formation of antibodies in the first few weeks of life , and the development of the immunity . It is located at the base of the neck and it manufactures lymphocytes . Another one is the spleen , situated in the left abdomen...