1 / 68

Lymphatic System

Lymphatic System. ST120: Concorde Career College. Lymphatic System . Objectives: Define the term lymph. Describe the functions of the lymphatic system. List and identify the structures of the lymphatic system and describe the function of each. Identify the origin of lymph.

dot
Download Presentation

Lymphatic System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Lymphatic System ST120: Concorde Career College

  2. Lymphatic System Objectives: • Define the term lymph. • Describe the functions of the lymphatic system. • List and identify the structures of the lymphatic system and describe the function of each. • Identify the origin of lymph.

  3. Lymphatic System Objectives: • Trace the flow of lymph through the body. • Describe the immune system and describe the immune response. • Describe the mechanism by which the immune system helps to maintain homeostasis.

  4. Lymphatic System Objectives: • Describe common diseases, disorders, and conditions of the lymphatic system including signs and symptoms, diagnosis, and available treatment options. • Demonstrate knowledge of medical terminology related to the lymphatic system verbally and in the written form.

  5. Lymphatic System Functions of the Lymphatic System • Removal of impurities • Lymphocyte processing

  6. Lymphatic System • The lymphatic system parallels (same direction)the circulatory system • Lymph vessels return tissue fluid to the blood & protect the body against foreign material • The lymphatic system includes: • Lymph fluid • Lymph vessels • Lymph nodes • Spleen • Thymus • And tonsils

  7. Lymph Fluid Lymph is the tissue fluid that enters and travels through the lymphatic vessels • Plasma flows out of blood capillaries into tissue spaces (interstitial fluid) – AKA Tissue fluid • Plasma diffuses out of the capillaries faster than it is reabsorbed, the remaining interstitial fluid is returned to the blood through the lymphatic system

  8. Lymphatic Capillaries • Lymphatic Capillaries - Carry lymph and resemble blood capillaries • Lacteals - Specialized lymphatic capillaries that carry chyle

  9. Lymph Vessels • Vessels of the lymphatic system start with the smallest blind (dead-ended) lymph capillaries • The walls of the lymphatic capillaries are a thin walled, single layer of loosely fit squamous epithelial cells making them highly permeable • Lymphatic capillaries join larger lymphatic arterioles that then join lymphatic arteries • Lymphatic vessels like the veins of the circulatory system have valves

  10. Lymph Flow

  11. Lymphatic System Relationship of Lymphatic Vessels to Circulatory System

  12. Thoracic Duct • Lymph returns to the blood flow through the thoracic duct and the left subclavianvein • Lymph from the lower body returns through the thoracic duct • Cisterna chyli– dilation at the beginning of the thoracic duct (pouch-like structure) • Lymph from a portion of the upper body also empties into the thoracic duct superior to the cisternachyli • Lymph from the upper left quadrant empties into the subclavian vein • Two terminal vessels include: Right Lymphatic duct & thoracic duct

  13. Lymphahtic Drainage

  14. Lacteal • Found in the villi of the small intestine • Responsible for absorbing fat-soluble nutrients (fatty acids and vit. A,D,E & K) • Fats are absorbed by the lacteals as chylomicron • Chylomicron: combination of fatty acids and glycerol to form triglycerides

  15. Lacteal

  16. Lymph nodes and nodules • Lymph Node: small ball shaped organs of the lymphatic system • Lymph Nodules: groups of lymph cells located beneath the epithelial layer of mucus membranes (ex. Respiratory tract and digestive tract) • Peyer’s patches: lymphatic nodules of the ileum • Filters pathogens and foreign material before returning to blood • Monitor the level of body fluid • Hematopoietic function – produce lymphocytes, macrophages, and monocytes • Located throughout the body • Cervical • Axillary • Inguinal

  17. Regional Lymph Nodes

  18. Lymph node Hilus Afferent vessels x4 pg.261 A&P Efferent vessels x1 Capsule Germinal centers Sinuses Trabecula

  19. Tonsils • Palatine Tonsils (throat) – located at each side of the oropharynx • Pharyngeal (Adenoids) – located on the posterior wall of the nasopharynx • Lingual Tonsils – located at the base of the tongue

  20. Tonsils

  21. Lymphedema • Abnormal accumulation of fluid in interstitial spaces • Causes: • Obstruction of a lymphatic vessel (tumors, inflammation) • Increased capillary BP • Abnormal uptake of fluid by the lymphatic capillaries due to trauma or surgical wound (often seen after mastectomy)

  22. Lymphedema

  23. Lymphedema

  24. Terms • Lymphadenitis: inflammation of lymph node/vessels • Metastasis: is the spread of a disease from one organ or part to another non-adjacent organ or part, causing a new cancer site • Lymphadenopathy: Any disease that usually involves the lymph glands

  25. Sentinel Lymph Node Biopsy • Method developed to determine if breast cancer has spread to lymph ducts or nodes in the axilla • Prevents the patient from having to undergo a lymph node dissection • Sentinel Node: first node the breast drains to Nuclear Medicine • A radioactive dye is injected into the area where the tumor is located as well as around the areola • Hours later photos will reveal the pathway used to exit the breast, this will reveal the sentinel node OR • Surgeon injects a blue dye into the breast that assists in visual of the nodes • Small incision is made in the axilla • A special probe picks up signals form the radioactive dye and gets “excited” when over an affected node • All blue and radioactive nodes are removed

  26. Spleen • Highly vascular and friable (easily crumbled/delicate) • Located behind the stomach • Contains lymphoid nodules (white pulp) • Filters blood (red pulp) cleans out foreign materials/microorganisms • Stores blood (approximately 200 ml) aids in maintenance of BP during severe hemorrhage • Hematopoietic function: lymphocytes, monocytes, leukocytes, fixed plasma cells • In a fetus the spleen produces erethrocytes

  27. Spleen Hilus Splenic artery Splenic vein

  28. Spleen cont. • #1 organ injured in MVA’s (motor vehicle accidents) despite being protected by the lower ribs • Splenectomy: surgical removal of the Spleen

  29. Lymphatic System Reticuloendothelial System • Responsible for destruction of obsolete RBCs, bacteria, cancer cells, and other potentially harmful foreign substances. • Utilizes monocytes distributed throughout the body such as Kupffer’s cells located in the liver

  30. Thymus • Located in the mediastinum • Composed of two lateral lobes bound by a connective tissue capsule • Proper function dependent on thymosin • Produces T-cells important in cell mediated immunity

  31. Thymus

  32. Lymphatic System Lymphatic and Immune Systems • Thymus • Bone marrow • Spleen • Tonsils • Lymph nodes • Lymph capillaries • Lymph vessels • Lymphocytes • Lymph

  33. Lymphatic System Immunologic Defenses • Provide the body with general defenses against disease. • Nonspecific Defenses • Specific Defenses

  34. Lymphatic System Nonspecific Defenses • Chemical and Mechanical Barriers • Phagocytosis • Natural Killer Cells • Inflammation • Fever • Interferon

  35. Lymphatic System Occurrence of Infection • Not every exposure to a pathogen results in infection. • Portal of Entry • Virulence • Toxins • Dose • Predisposition

  36. Lymphatic System Barriers Against Infection • Chemical • Body secretions • Mechanical • Skin • Mucous membranes • Cilia

  37. First Line of Defense • Our first line of defense against microbes include: • Skin • Mucous membranes • Secretions

  38. Skin • Unbroken skin prevents microbes from entering the body (keratin) • Broken skin such as Burns, Cuts, Scratches open the doors for an invasion of microbes such as Staphylococcus aureus • Sweat glands and Sebaceous gland secrete acids that kill or inhibit the growth of bacteria on the skin

  39. Mucous Membranes • Line tracts open to the exterior of the body (respiratory, digestive, urinary) • Goblet cells secrete mucous to line the membranes and “catch” microbes • Cilia catch and pass debris up to the pharynx to be expelled • Glands in the stomach produce highly acidic gastric juice that kills most bacteria • Helicobacter Pylori is an exception… can cause stomach and duodenal ulcers

  40. Second Line of Defense • If pathogens penetrate the 1st line of defense they will encounter the body’s 2nd line of defense Circulatory and chemical defenses • Circulatory Defenses: • Phagocytes • Complement proteins • Iron • Fever • Inflammatory response • Interferons

  41. Phagocytes • Leukocytes responsible for phagocytosis • Phagocytosis: the process of surrounding and ingesting another microbe • Granulocytes • Neutrophils – motile and effective phagocytes • Eosinophils – attach to parasites and secrete peroxide ions which kill them. Play a larger phagocytic role during allergic response • Basophils • Agranulocytes • Monocytes – enter body tissues and mature into stationary macrophages or travel through blood to infection site (wandering macrophages) • Kupffer cells (liver), microglia (brain) • Lymphocytes – are not phagocytes but are important in the immune response

  42. Phagocytosis • Chemotaxis – chemicals attract phagocytes to injured tissues or bacteria • Adherence – antibody molecules secrete a serum protein that can coat a bacterial cell and promote attachment (opsonization) • Ingestion – phagocyte surrounds the microbe • Pseudopods: “false feet” that extent to cover a microbe • The resulting sac is called a Phagosome • Digestion – phagosome is moved into the cytoplasm (phagolysosome) and enzymes (from the lysosomes) destroy the bacteria • Degranulation – digestion process

  43. Complement proteins • Group of 25-30 serum proteins found in blood plasma • Circulate inactive until needed in the antibody-antigen reaction • Activated Proteins: increase inflammatory response, assist in lysis of antigen, attracts phagocytes • Complement cascade: sequence of proteins “bore” holes into bacteria causing an accumulation of fluid that eventually ruptures the cell

  44. Iron • Virulence of bacteria increases when free iron is present • Leukocytes: produce interleukin-1 (IL-1), stimulates the liver to store iron depriving bacteria of necessary free iron

  45. Inflammatory response • Inflammation is a beneficial and necessary response to injury • The four signs of inflammation include: • Pain • Heat • Redness • Swelling • Three stages of inflammation include: • Vasodilatation • Phagocyte migration • Tissue repair

  46. Inflammatory Response • Vasodilation: Increased blood flow to area and increased permeability of blood vessels • Histamine, kinins, and prostaglandins: chemicals released by damaged tissues responsible for vasodilatation

  47. Fever • An abnormally elevated body temperature (controlled by hypothalamus) • Systemic response frequently caused by viral or bacterial invasion • Symptoms include heat, shivering and increased metabolism rate • Vasodilatation and sweating signify the temperature falling “ fever breaking”

  48. Interferons- produced by T-cells • Released to protect other cells by interferring with the ability of the virus to reproduce as it moves from cell to cell • Proteins produced by leukocytes, T-lymphocytes, and fibroblasts in response to infection “interfere with viral replication” • Proteins enter surrounding cells and inhibit the synthesis of proteins needed by invading viruses for multiplication • They interfere with viral replication Pg. 269 A&P

More Related