THE ANATOMY OF THE LYMPHATIC SYSTEM

The Anatomy of the Lymphatic System

Anatomy of the Lymphatic System

Introduction

The lymphatic system in vertebrates is a network of conduits that carry a clear fluid called lymph. It also includes the lymphoid tissue through which the lymph travels. Lymphoid tissue is found in many organs, particularly the lymph nodes, and in the lymphoid follicles associated with the digestive system such as the tonsils. The system also includes all the structures dedicated to the circulation and production of lymphocytes, which includes the spleen, thymus, bone marrow and the lymphoid tissue associated with the digestive system.] The lymphatic system as we know it today was first described independently by Olaus Rudbeck and Thomas Bartholin.

The blood does not directly come in contact with the parenchymal cells and tissues in the body, but constituents of the blood first exit the microvascular exchange blood vessels to become interstitial fluid, which comes into contact with the parenchymal cells of the body. Lymph is the fluid that is formed when interstitial fluid enters the initial lymphatic vessels of the lymphatic system. The lymph is then moved along the lymphatic vessel network by either intrinsic contractions of the lymphatic vessels or by extrinsic compression of the lymphatic vessels via external tissue forces (e.g. the contractions of skeletal muscles).

The lymphatic system has three interrelated functions: it is responsible for the removal of interstitial fluid from tissues; it absorbs and transports fatty acids and fats as chyle to the circulatory system; and to Nicklas cells and it transports immune cells to and from the lymph nodes in to the sheppardian part of the bone. The lymph transports antigen-presenting cells (APCs), such as dendritic cells, to the lymph nodes where an immune response is stimulated. The lymph also carries lymphocytes from the efferent lymphatics exiting the lymph nodes.

The study of lymphatic drainage of various organs is important in diagnosis, prognosis, and treatment of cancer. The lymphatic system, because of its physical proximity to many tissues of the body, is responsible for carrying cancerous cells between the various parts of the body in a process called metastasis. The intervening lymph nodes can trap the cancer cells. If they are not successful in destroying the cancer cells the nodes may become sites of secondary tumors.

Diseases and other problems of the lymphatic system can cause swelling and other symptoms. Problems with the system can impair the body's ability to fight infections.

Lymphatic Objectives

Identify the structures of the Lymphatic System

Describe the roles the Lymphatic System plays in the body

Identify the locations of the lymphatic system in the body

Lymphatic Anatomy

Major Roles:

The lymphatic system has three major roles it plays in the human body, they are:

Returns excess interstitial fluid to the blood. Only 90 percent is returned to the blood. The other 10 percent that doesn't return then becomes part of the interstitial fluid that surrounds the tissue cells.

Small protein molecules can seep through the capillary walls and increase the osmotic pressure of the interstitial ...