Lymphatic System

1. Lymphatic System DHO, 7th Edition Chapter 7:9

2. Introduction • What happens to the “glands” in your neck when you have a sore throat or bad cold? • Why does this happen? • These “glands” are really lymph nodes, the topic we are going to discuss.

3. 7:9 Lymphatic System • Lymphatic system consists of: • Lymph • Lymphatic vessels • Lymph nodes (glands) • Works with the circulatory system • Removes waste and excess fluids from the body tissues

5. Lymph • Thin, watery fluid • Composed of intercellular or interstitial fluid that forms when plasma diffuses into tissues spaces • Composed of water, digested nutrients, salts, hormones, O2, CO2 ,lymphocytes, and metabolic wastes such as urea • When fluid enters the lymphatic system, it becomes known as “lymph”

6. Lymphatic Vessels • Lymphatic vessels carry lymph • Located throughout the body in almost all issues that have blood vessels • Lymphatic capillaries • Small, open-ended lymph vessels • Act like drainpipes • Pick up lymph at tissues throughout the body • Capillaries join together to form larger lymphatic vessels

7. Lymphatic Vessels • Lymphatic vessels contain valves to allow fluid to flow in one direction • Contraction of skeletal muscles against lymph vessels cause lymph to flow through vessels • Vessels pass through lymph nodes. • Specialized lymphatic capillaries, called lacteals, are located in area of small intestine • Pick up digested fats, or lipids • When lymph is mixed with lipids, its called “chyle” • Lacteals transport the chyle to the bloodstream through the thoracic duct

9. Lymph Nodes • Popularly called “glands” • Located all over the body, usually in groups or clusters • Small, round masses ranging in size from a pinhead to an almond • Lymph nodes filter lymph and remove impurities such as • Carbon, cancer cells, pathogens, dead blood cells • The tissue in nodes also produce lymphocytes and antibodies (used to combat infection) • Purified lymph, with lymphocytes and antibodies added, leaves nodes by a single lymphatic vessel

10. 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: • Right lymphatic duct • Thoracic duct

11. 2 Lymphatic Ducts • Right lymphatic duct • Short tube • Receives purified lymph from the right side of the head and neck, right chest, and right arm • Empties into the right subclavian vein, returning purified lymph to the blood • Thoracic duct • Much larger tube • Drains lymph from the rest of the body • Empties into the left subclavian vein • Has an enlarged pouch-like structure called the cisterna chyli • Serves as storage area for purified lymph • Receives chyle from intestinal lacteals

12. Lymph Tissue • Located throughout the body in addition to being in lymph nodes, examples include • Tonsils • Spleen • Thymus

13. Tonsils • Masses of lymph tissue • Filter interstitial fluid • Have 3 pairs of tonsils • Palatine tonsils on each side of soft palate • Pharyngeal tonsils (also called adenoids) located in nasopharynx (upper part of throat) • Lingual tonsils on back of tongue

14. Spleen • Organ located on left side of abdomen in back of upper part of stomach • Produces leukocytes and antibodies • Destroys old erythyrocytes • Stores erythrocytes to release into bloodstream is excessive bleeding occurs • Destroys thrombocytes • Filters some metabolites and wastes from tissues

15. Thymus • Mass of lymph tissue located in center of upper chest • Atrophies after puberty and is replaced by fat and connective tissue • Functions during early life until lymph nodes take over after puberty • Produces antibodies • Manufactures lymphocytes to fight infection

17. Diseases and Abnormal Conditions • Adenitis • Hodgkin’s disease • Lymphangitis • Splenomegaly • Tonsillitis

18. Adenitis • Inflammation or infection of lymph nodes or glands • Occurs when pathogens or cancer cells enter nodes and infect the tissue • Symptoms: swollen painful nodes, fever • Abscess may form in node if infection is not treated • Treatment: antibiotics an warm, moist compresses

19. Hodgkin’s Disease • Chronic malignant disease of lymph nodes • Most common form of lymphoma (tumor of lymph tissue) • Symptoms: Painless swelling of lymph nodes, • Fever and night sweats, weight loss, fatigue, pruritus (itching) • Treatment: chemotherapy and radiation

20. Lymphangitis • Inflammation of lymphatic vessels • Usually occurs from infection in an extremity • Symptoms: • Red streak extending up from source of infection • Fever and chills • Tenderness or pain • Treatment • Antibiotics for infection • Rest and elevation of affected part • Warm, moist compresses

21. Splenomegaly • Enlargement of the spleen • Causes: abnormal accumulation of erythrocytes, mononucleosis, and cirrhosis of the liver • Symptoms: swelling and abdominal pain • Increase destruction of blood cells can lead to anemia, leukopenia, and thrombocytopenia • If spleen ruptures, intraperitoneal hemorrhage and shock can lead to death • Splenectomy done in severe cases

22. Tonsillitis • Inflammation or infection of the tonsils • Usually involves the pharyngeal and palatine tonsils • Symptoms: • Throat pain and fever • Dysphagia • White or yellow spots of exudate on tonsils • Swollen lymph nodes by the mandible • Treatment • Antibiotics and analgesics for pain • Warm throat irrigations • Rest and fluids • Tonsillectomy in chronic cases

23. The End