The Lymphatic System

The lymphatic system is a collection of ducts organs and tissues, which collect excess fluid or lymph from your body and transport it back to the heart. The lymphatic system also helps to defend the body against infection.

Lymph vessels of the neck

These lymph vessels drain tissue fluid, or lymph, from the head and neck. The fluid is filtered through lymph nodes in order to remove foreign particles before it re-enters the bloodstream. This helps to defend your body against infection. When you have a sore throat, the lymph nodes in your neck become swollen and tender.

Inside a Lymph Node

The cells are made inside the round follicles to help in the fight against infection. The are between the follicles cleanses and filters excess tissue fluid, called lymph, as it passes through the lymph node.

Lymph vessels of the chest

Tissue fluid, or lymph, from your arms and chest drains through the lymph nodes in your armpits. Inside each node, the lymph is filtered and unwanted matter is removed. All filtered fluid eventually drains through two large lymph vessels in your chest: the thoracic duct and the right lymphatic duct. These join two veins at the base of your neck to return lymph to the bloodstream.

Thymus Gland

The thymus is an organ that forms part of the body's defense system. It is situated in the upper part of the chest and consists of two lobes. Thymus tissue contains white blood cells, called lymphocytes, which mature under the influence of hormones produced by the thymus. These white cells help to protect the body against disease by attacking invading organisms. They thymus is large and active in children but shrinks with age.

Heart

Your heart is a fist-sized, muscular bag, weighing about 450g(1 pound), which pumps blood around your body. Its walls are made of cardiac muscle, which contracts about 70 times per minute. Your heart is actually two pumps joined together. Each one has an upper chamber, or atrium, into which blood enters. Blood then passes on to a lower, thick-walled chamber, or ventricle, which pumps blood out of the heart. The pump to the right side pushes blood to your lungs. It then returns to the pump on the left, which pushes it around your body.

Thoracic Duct

The thoracic duct is the major vessel of the lymphatic system. It collects excess tissue fluid, called lymph, from most of the body. The thoracic duct begins below the diaphragm, travels upward in front of the backbone, and drains into a vein at the base of the neck.

Lymph Vessel of the Abdomen

Excess tissue fluid, or lymph, from all the abdominal organs, including your stomach, liver, pancreas, and intestines, drains along lymph vessels to the lymph nodes in the abdomen. Inside these nodes, the fluid is filtered to remove any harmful particles that could cause infection. From here, the filtered fluid is carried back to the heart in a large vein like vessel called the thoracic duct. This duct opens into a chest vein to return fluid to the bloodstream.

Spleen

The spleen is a large organ that helps to fight infection. It lies in the upper left side of the abdomen, protected by the lower ribs. One of its main functions is to provide a site for the proliferation of two types of cells - macrophages and lymphocytes that clean the blood and help defend the body against diseases. Macrophages filter blood by removing bacteria, debris, and worn-out red blood cells; lymphocytes destroy invading microorganisms.

Lymph Vessels of the Pelvis

Lymph nodes are usually found in clusters. One example of this is at the top of each thigh in your groin. Lymph vessels drain excess tissue fluid, called lymph from the lower body into the lymph nodes. Inside each node, a mesh of white blood cells, or lymphocytes, filters harmful organisms in order to prevent the spread of infection.