Lymphatic System Anatomy (PDF)

LYMPHATIC SYSTEM (Lymphoid System) - Consists of: o Lymph – the fluid o Vessels called Lymphatic Vessels that transport the lymph o Structures and organs containing lymphatic tissue red bone marrow LYMPHATIC SYSTEM – Primary Functions Lymphatic system has 3 primary functions: 1. Maintena...

LYMPHATIC SYSTEM (Lymphoid System) - Consists of: o Lymph – the fluid o Vessels called Lymphatic Vessels that transport the lymph o Structures and organs containing lymphatic tissue red bone marrow LYMPHATIC SYSTEM – Primary Functions Lymphatic system has 3 primary functions: 1. Maintenance of fluid balance in the internal environment 2. Transport dietary lipids 3. Carries out immune responses LYMPHATIC SYSTEM - Components Lymph Lymphatic Vessels Lymphatic Capillaries Lymphatic Trunks Lymphatic Ducts Lymphatic Organs Primary lymphatic organs - sites where stem cells divide and become immunocompetent ( Bone Marrow and Thymus) Secondary lymphatic organs – sites where most of immune response occur (lymph nodes, spleen, tonsils, and lymphatic nodules) FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 2 LYMPHATIC SYSTEM - Lymph Lymph (lymphatic fluid)  clear, yellow fluid that forms when fluid from blood vessels seeps into tissues  Composed primarily of interstitial fluid with variable amounts of lymphocytes, bacteria, cellular debris, plasma proteins and other cells  Similar to blood plasma but has less protein and more fat  The body produces 3-4 liters of lymph daily FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 3 LYMPHATIC SYSTEM – Primary Organs Primary Organs  are the sites where stem cells divide and become immunocompetent Red Bone Marrow - immunocompetent B cells and pre-T Cells are produced - produces mature lymphocytes (B-lymphocytes) Thymus - the pre-T cells migrate to thymus where they become immunocompetent T cells FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 4 LYMPHATIC SYSTEM – Thymus Thymus – is a bilobed organ located in the mediastinum - each thymic lobe consist of: ▪ outer cortex ▪ central medulla FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 5 LYMPHATIC SYSTEM – Thymus: Cortex Cortex is composed of large number of t cells Epithelial cells - serve as framework for as many as 50 T cells - epithelial cells help “educate” the pre-T cells in a process known as positive selection FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 6 LYMPHATIC SYSTEM – Thymus: Cortex Dendritic cells- assist the maturation process Macrophages help clear out debris of dead and dying cells. The surviving T cells enter the medulla FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 7 LYMPHATIC SYSTEM – Thymus: Medulla Medulla consists of widely scattered, more mature T cells, epithelial cells, dendritic cells and macrophages It consists of thymic corpuscles called Hassall’s corpuscles which believed to FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 8 be aged and degenerated cells. LYMPHATIC SYSTEM – Bone Marrow - Tissue that produces lymphocytes - It is where the hematopoiesis occurs. - The B cells undergoes nearly all its development in the red bone marrow, whereas the immature T cell, called a thymocyte, leaves the bone marrow and matures largely in the thymus gland FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 9 LYMPHATIC SYSTEM – Secondary Organs The secondary lymphatic organs and tissues are the sites where most immune responses occur. They include lymph nodes, the spleen, and lymphatic nodules (follicles) LYMPHATIC SYSTEM – Lymph Nodes - sometimes referred to as the “filters of the lymph” - Remove debris and pathogens from the lymph - Lymph nodes are 1-25mm (0.04 – 1 in) long FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 10 - covered by a capsule of dense connective tissue and divided into compartments thru capsular extension called “trabeculae” to provide support and routed for blood vessel - Trabeculae penetrate inward and divide each node into lobules FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 11 LYMPHATIC SYSTEM – Lymph Nodes FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 12 LYMPHATIC SYSTEM – Lymph Nodes The capsule, trabeculae, reticular fibers, and fibroblasts constitute the stroma (supporting framework of connective tissue) of a lymph node The parenchyma (functioning part) of a lymph node is divided into a superficial cortex and a deep medulla. FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 13 LYMPHATIC SYSTEM – Lymph Nodes Its inner cortex is called paracortex which consist mainly of T cells and dendritic cells The medulla of lymph node contains B cells, antibodyproducing plasma cells that have migrated out into the medulla. FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 14 LYMPHATIC SYSTEM – Flow of Lymph in Lymph Node Lymph flows through a node in one direction only If enters lymph node through several afferent lymphatic vessels Within the node, lymph enters sinuses, a series of irregular channels Efferent lymphatic vessels leave the node at the hilum FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 15 LYMPHATIC SYSTEM – Flow of Lymph in Lymph Node Afferent lymphatic vessel Route of lymph through lymph node: Efferent lymphatic vessel Subcapsular sinus Medullary sinus Trabecular sinus FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 16 LYMPHATIC SYSTEM – Lymph Nodes FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 17 LYMPHATIC SYSTEM – Spleen  Spleen is the largest single mass of the lymphatic tissue in the body measuring about 12cm (5in.) in length  It is located in the left hypochondriac region  sometimes called the “filter of the blood”  Location oof immune responses to bloodborne pathogens FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 18 LYMPHATIC SYSTEM – Spleen  The parenchyma of the spleen consist of two different kinds of tissue: white and red pulp  White pulp is lymphatic tissue, consisting mostly of lymphocytes and macrophages  Red pulp consists of blood-filled venous sinuses and cords of splenic tissue called splenic (Billroth’s) cords  Splenic cords consist of red blood cells, lymphocytes, macrophages, plasma cells and granulocytes FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 19 LYMPHATIC SYSTEM – Spleen FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 20 LYMPHATIC SYSTEM – Spleen  Blood flowing into the spleen through the splenic artery enters the central arteries of the white pulp  Within the white pulp, B cells and T cells carry out immune functions  Spleen macrophages destroy blood-borne pathogens by phagocytosis  Within the red pulp, it performs the three functions related to blood cells: 1. removal by macrophages of ruptured, worn out, or defective blood cells and platelets; 2. storage of platelets, up to one-third of the body’s supply; and 3. production of blood cells (hemopoiesis) during fetal life. FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 21 LYMPHATIC SYSTEM – Lymphatic Nodules egg-shaped masses of lymphatic tissue that are not surrounded by a capsule They are scattered throughout the connective tissue of mucous membranes lining the gastrointestinal, urinary, and reproductive tracts and the respiratory airways also referred to as mucosa-associated lymphatic tissue (MALT) LYMPHATIC SYSTEM – Lymphatic Nodules Among these are the tonsils in the pharyngeal region and the aggregated lymphatic follicles (Peyer’s patches) in the ileum of the small Intestine. FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 22 LYMPHATIC SYSTEM – Flow of Lymph FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 23 FLOW OF LYMPH BLOOD LYMPHATIC DUCTS JUNCTION OF THE INTERNAL JUGULAR AND SUNCLAVIAN VEINS INTERSTITIAL SPACES LYMPHATIC TRUNKS LYMPHATIC LYMPHATIC VESSELS CAPILLARIES WHITE BLOOD CELLS (LEUKOCYTES) - Vital component of the blood - Their role is to fight infection - Classified as either Granular or Agranular FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 24 - Granular leukocytes – neutrophils, eosinophils, basophils - Agranular leukocytes – lymphocytes and monocytes - Normal count: 4,000-11,000 per microliter of blood WHITE BLOOD CELLS COMPONENTS NEUTROPHILS  Are phagocyte, have a trilobed nucleus and make up the largest percentage of leukocytes  Responds most quickly to tissues  Releases enzyme called lysozyme – destroy certain bacteria and strong oxidants like hydrogen peroxide FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 25  Also contains defensins – protein that exhibit a broad range of antibiotic activity against bacteria and fungi WHITE BLOOD CELLS COMPONENTS MONOCYTES  Takes longer to reach a site of infection than neutrophil but they arrive in large number  They differentiate into wandering macrophages which clean up cellular debris and microbes by phagocytosis FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 26 WHITE BLOOD CELLS COMPONENTS EOSINOPHILS  primarily deal with parasitic infections  the predominant inflammatory cells in allergic reactions  Releases enzymes that break downs chemical mediators released by the other cells WHITE BLOOD CELLS COMPONENTS BASOPHILS  main responsible for short-term inflammatory response (particularly from allergy or irritation) by releasing the FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 27  chemical histamine, which causes the vasodilation that occurs with inflammation  produced heparin which prevents the blood from clotting too quickly WHITE BLOOD CELLS COMPONENTS LYMPHOCYTES  Major soldiers in the immune system  Has three main types namely, B cells , T cells, and natural killer cells  B cells are particularly effective in destroying bacteria and inactivating their toxins FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 28  T cells attack viruses, fungi, transplanted cells, also responsible for transfusion reaction and allergies FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 29 WHITE BLOOD CELLS FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 30 FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 31 IMMUNITY  body's ability to resist or eliminate potentially harmful foreign materials or abnormal cells  consists of following activities:  Defense against invading pathogens (viruses & bacteria)  Identification & destruction of abnormal or mutant cells (primary defense against cancer)  Rejection of 'foreign' cells (e.g., organ transplant) FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 32 TWO TYPES OF IMMUNE DEFENSES FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 33 FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 34 INNATE (NON-SPECIFIC) IMMUNITY  refers to defenses that are present at birth.  includes the external physical and chemical barriers (skin and mucous membranes)  Also include various internal nonspecific defenses such as antimicrobial proteins, natural killer cells and phagocytes  Innate immune responses can start acting immediately on encounter with infectious agents  does not generate long-term protective immunological memory FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 35 INNATE (NON-SPECIFIC) IMMUNITY FIRST LINE a. PHYSICAL i. Skin (epidermis) / mucous membranes ii. Hairs/cilia b. CHEMICAL / fluids i. Sebum ii. Gastric juices iii. Tears from lacrimal gland iv. Saliva FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 36 INNATE (NON-SPECIFIC) IMMUNITY SECOND LINE Antimicrobial proteins (AMPs)- inhibit microbial growth (dermicidin, defensins, thrombocidin) Interferons- do not prevent viruses from attaching to and penetrating host cells, they do stop replication (eg. alpha-, beta-, and gamma-IFN.) FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 37 INNATE (NON-SPECIFIC) IMMUNITY SECOND LINE Iron-binding proteins inhibit the growth of certain bacteria by reducing the amount of available iron. Eg: transferrin, lactoferrin, ferritin, and hemoglobin Complement system -system causes cytolysis (bursting) of microbes, promotes phagocytosis, and contributes to inflammation FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 38 Natural Killer Cells they can kill a wide variety of infected body cells and certain tumor cells. NK cells attack any body cells that display abnormal or unusual plasma membrane proteins. Two ways perforin (inserted) and granzymes ( release) FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 39 Phagocytes (dendritic cells, eosinophils, macrophages, monocytes, neutrophils)  Phagocytosis  the ingestion of microbes or other particles such as cellular debris (Neutrophils and macrophages)  Occurs in five phases: chemotaxis, adherence, ingestion, digestion, and killing FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 40 Phases of Phagocytosis FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 41 FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 42 INFLAMMATION INFLAMMATION  is a nonspecific, defensive response of the body to tissue damage  is protective response to: oEliminate the initial cause of cell injury oTo remove the damaged tissue oGenerate new tissue FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 43 INFLAMMATION Systemic inflammation results in:  Production of large numbers of neutrophils from bone marrow  Production of pyrogens (substance that produces a rise in body temperature)  Loss of fluid from blood Hallmarks of Inflammation REDNESS (RUBOR) Due to capillary dilation resulting from increased blood flow FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 44 SWELLING (TUMOR) Due to passage of plasma from blood stream to the damaged site HEAT (CALOR) Due to capillary dilation resulting from increased blood flow PAIN OF DISCOMFORT (DOLOR) Mainly due to destruction of tissue LOSS OF FUNCTION (FUNCTIO LAESA) FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 45 Stages of Inflammatory Response  the inflammatory response has three basic stages: 1. Vascular permeability/ vasodilation and Release of mediators , 2. Exudate production and Fibrinogen, Thromboplastin & Platelet formation 3. tissue repair/ regeneration Fever  It commonly occurs during infection and inflammation. FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 46  Elevated body temperature intensifies the effects of interferons, inhibits the growth of some microbes, and speeds up body reactions that aid repair  Triggered by cytokines (interleukin 1) and pyrogens ADAPTIVE (SPECIFIC) IMMUNITY  Ability of the body to defend itself against specific invading agents such as bacterial, toxins, viruses and foreign tissues  involves lymphocytes called T lymphocytes (T cells) and B lymphocytes (B cells) FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 47 CLONE PRINCIPLE Clonal selection is the process by which a lymphocyte proliferates (divides) and differentiates The result of clonal selection is the formation of a population of identical cells, called a clone Major Histocompatibility Complex  Also called Human Leukocyte antigens (HLA)  There normal function is to help T cells recognize that an antigen is foreign, not self.  Two types of MHC antigens are Class I and Class II. FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 48  1. Class I MHC (MHC I) molecules are built into plasma membranes of all body cells except red blood cells 2. Class II MHC (MHC II) – molecules appear on the surface of antigen presenting cells Antigen Processing and Presenting Antigenic Processing  antigenic proteins are broken down into peptide fragments that then associate with MHC molecules. Antigenic Presentation The insertion of the antigen-MHC complex into the plasma membrane Antigen presenting cells - dendritic cells, macrophages, and B cells FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 49 Processing and Presenting EXOGENOUS ANTIGEN Lymphatic tissue Processing and + to present to T Presenting APCs cells T-cells recognize and Trigger Adaptive bind with MCH II Immunity complex FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 50 Types of Adaptive Immunity A. Humoral Immunity  B lymphocytes secrete antibodies that eliminate extracellular microbes B. Cell Mediated Immunity T lymphocytes either activate macrophages to destroy, phagocytosed microbes or kill infected cells FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 51 CELL MEDIATED IMMUNITY Particularly effective against: 1. Intracellular pathogens that resides within host cells (fungi, parasites and viruses) 2. Some cancer cells 3. Foreign tissue transplants FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 52 TYPES OF T- CELLS 3 MAIN TYPES 1. Helper cells  Also known as CD4+ T cells 2. Cytotoxic cells  also termed as CD8+ cells  recognized foreign antigens combined with major histocompatibility class 1 molecules 3. Memory cells  cellular immunity FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 53 T-cell Activation FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 54 FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 55 ANTIBODY –MEDIATED (HUMORAL) IMMUNITY  works mainly against extracellular pathogens, which include any viruses, bacteria, or fungi that are in body fluids outside cells. FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 56 ANTIBODY –MEDIATED (HUMORAL) IMMUNITY B CELLS /PLASMA CELLS  Forms clones of B cells which consist of Plasma cells and memory B cells  prolific producers of customized antibodies (IgG antibodies)  Works mainly against: 1. Antigens present in the body fluids 2. Extracellular pathogens that multiply in body fluids but rarely enter body cells FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 57 B-cell Activation FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 58 ANTIBODIES  Belongs to a group of glycoproteins called globulins or immunoglobulins  Most antibodies contain four polypeptide chains  Actions: 1. Neutralizing Antigen-blocks toxins which prevents attachment of some viruses to body cells 2. Immobilizing bacteria- antigen –antibody reaction inhibit motility to limit spread into tissues FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 59 FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 60 IMMUNOGLOBULINS IgG Protects from bacteria/ viruses by enhancing phagocytosis, neutralizing toxins, triggering complement system, crosses the placenta from mother to fetus IgM First antibody class to be secreted by plasma cells after an initial exposure to antigens. Activates complement and causes agglutination and lysis of microbes IgE Located on Mast cells and basophils Involved in allergic and hypersensitivity reactions Provides protection against parasitic worms FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 61 IgD Mainly found on the surface of B cells as antigen receptors Involved in activation of B cells IgA Levels decrease during stress, provides localized protection on mucous membranes against bacteria and viruses FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 62 Immunological memory Immunological memory is due to the presence of long-lasting antibodies and very long-lived lymphocytes that arise during clonal selection of antigen-stimulated B cells and T cells FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 63 Types of Antibody-mediated immunity (Humoral) A. Active Immunity  antibodies are produced in response to an Antigens  active immunity results when exposure to a disease organism triggers the immune system to produce antibodies to that disease B. Passive Immunity  antibodies are produced by another source, human/animal provided when a person is given antibodies to a disease rather than producing them through his or her own immune system FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 64 SPECIFIC DEFENSES ACTIVE PASSIVE results from antibodies having the Natural active Natural passive obtained disease and immunity: immunity: through recovering Ab formed Ab transferred placenta or successfully resulting from from mother to breast milk infection baby FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 65  antibodies conferred by Artificial active transferred Artificial passive immunization immunity: from sensitized immunity: person such as with an Vaccines or Injected Ab antigen Toxoids gamma globulin Hypersensitivity  a state of altered reactivity in which the body reacts with an exaggerated immune response to a foreign agent Type I (anaphylactic) reactions – most common –exposure to certain allergens Type II (cytotoxic) reactions –blood transfusion FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 66  Type III (immune-complex) reactions – RA Type IV (cell-mediated) reactions -delayed hypersensitivity reactions - usually appear 12–72 hours after exposure to an allergen AUTOIMMUNE Immune system fails to display self- tolerance and attack’s the person own tissues Autoimmune means your immune system cannot tell the difference between these foreign invaders and your body’s healthy tissues and creates autoantibodies that attack and destroy healthy tissue ("auto" means "self") Thank you FRANCES ANNE R. CORPUZ, INSTRUCTOR 2024-2025 Page 67