Lymphatic System

Overview: 2. Works with the circulatory system 1. Lymphatic system consists of lymph, lymph vessels, lymph nodes, and lymph tissue 2. Works with the circulatory system 3. Removes waste and excess fluid from the tissues

Lymph 1. Thin, watery fluid 2. Composed of intercellular or interstitial fluid that forms when plasma diffuses into tissue spaces. 3. Composed of water, digested nutrients, salts, hormones, oxygen, carbon dioxide, lymphocytes, and metabolic wastes such as urea 4. When fluid enters lymphatic system, be comes known as lymph

Lymphatic Vessels/”Lymphatics” 1. Located throughout the body in almost all tissues that have blood vessels

Lymphatic Capillaries a. Small, open-ended lymph vessels b. Act like drainpipes c. Pick up lymph at tissues throughout the body d. Capillaries join together to form larger lymphatic vessels

Lymphatic Vessels cont: Lymphatic vessels carry lymph Contractions of skeletal muscles against lymph vessels cause lymph to flow through vessels Vessels pass through lymph nodes Contain valves that keep the lymph flowing one way – towards the heart

Lacteals Specialized lymphatic capillaries, called lacteals, located in area of small intestine a. Pick up digested fats or lipids b. When lymph is mixed with the lipids it is called chyle c. Lacteals transport the chyle to the blood stream through the thoracic duct

Lymph Nodes Popularly called “glands” Located all over the body usually in groups or clusters – principal groupings are located in the neck, armpits, chest, abdomen, pelvis, and groin Small, oval masses ranging in size from a pinhead to an almond

http://www.youtube.com/watch?v=Kh-XdNnTZUo

Lymph Nodes cont: Lymph vessels bring lymph to the nodes Nodes filter the lymph and remove impurities such as: Carbon Cancer cells Pathogens or disease producing organ Dead blood cells

Lymph Nodes cont: Lymphatic tissue in nodes also produces substances such as: Lymphocytes: a type of leukocyte or white blood cell Antibodies: substances used to combat infection F. Purified lymph, with lymphocytes and antibodies added, leaves the lymph node by one or two lymphatic vessels

Lymphatic Ducts As lymphatic vessels leave the lymph nodes, they continue to join together to form larger lymph vessels Eventually they drain into one of two lymphatic ducts: the right lymphatic duct or the thoracic duct

Right Lymphatic Duct Short tube Receives all the purified lymph from the right side of the head and neck, the right chest, and the right arm Empties into the right subclavian vein, returning the purified lymph to the blood

Thoracic Duct Much larger tube Drains the lymph from the rest of the body Empties into the left subclavian vein Enlarged pouchlike structure called the cisterna chyli is located at the start of the thoracic duct

Cisterna Chyli Serves as a storage area for purified lymph Receives chyle from the intestinal lacteals

Lymph Tissue Located throughout the body in addition to being in the lymph nodes Tonsils, spleen, and thymus are examples of lymphatic tissue

Tonsils Masses of lymph tissue Filter interstitial fluid Three pairs of tonsils Palatine tonsils on each side of the soft palate Pharyngeal tonsils (also called adenoids) located in the nasopharynx (upper part of the throat) Lingual tonsils on the back of the tongue

Spleen Organ located on the left side in back of the upper part of the stomach Produces leukocytes and antibodies Destroys old erythrocytes or red blood cells

Spleen Stores erythrocytes to release into blood stream if excessive bleeding occurs Destroys thrombocytes or platelets Filters some metabolites and wastes from tissues http://www.youtube.com/watch?v=0CqWul ccLMo

Thymus Mass of lymph tissue located in the center of the upper chest Atrophies or wastes away after puberty and is replaced by fat and connective tissue

Thymus Functions during early life Produces antibodies Manufactures lymphocytes to fight infection Function is taken over by lymph nodes after it atrophies http://www.youtube.com/watch?v=fFXQV- XJf3M