Lymphatic and Immune Systems Notes

Total Page:16

File Type:pdf, Size:1020Kb

Lymphatic and Immune Systems Notes Lymphatic and Immune Systems Notes The lymphatic system in general: The lymphatic system is a vast collection of cells and biochemical that travel in lymphatic vessels, and the organs and glands that produce them o It is closely associated with the cardiovascular system because they both circulate fluid throughout the body and lymph (fluid) in formed from plasma o Protects against infections from pathogens (bacteria, viruses, parasites, etc.) o Lymphatic pathways begin at lymphatic capillaries which interweave between cardiovascular capillaries . Lymph node (bulb) > Lymphatic trunks (like arteries or veins) > Lymphatic capillaries (like cardiovascular capillaries) o Walls of the lymphatic vessels are thin and open up with one-way valves at the capillaries to take in lymph . These all lead to lymph nodes which collect fluid, filter it, and release it back to the body (up to 3 liters a day! That’s more than half your body fluids) The right thoracic duct rotates from right thoracic area to right jugular to right subclavian, and right upper limb Thoracic duct rotates lymph for the rest of the body o Lymph fluid is mostly plasma but without some of the nutrients so that it can enter the valves of lymphatic capillaries o Fluid is moved from high to low pressure (osmosis) as well as pushed along by contracting muscles . This prevents fluid from accumulating which causes edema a.k.a. swelling . Function of lymph: 1. Absorb dietary fats from intestines 2. Return small proteins to body and blood 3. Transport foreign particles to lymph nodes for destruction Lymphatic and immune system specifics: Lymph nodes are glands with specialized cells called lymphocytes and macrophages which are used to destroy foreign particles o Lymph nodes make lymphocytes (check thymus and spleen for the “how”) 1. B cells: immune cells produced in bone marrow 2. T cells: thymus derived cells; immune cells produced by thymus 3. NK cells: natural killer cells are different from B and T cells because they produce the cytotoxins to kill cancer cells Lymph nodes can also control lymph nodules which function singularly from the lymph flow 1. Tonsils: these glands are located at the top of the esophagus; filter anything that comes in through the mouth (breathing, eating, etc.) 2. Peyer’s Patches: these are the mucosal linings of the small intestines; covered in microvilli (similar to cilia or microscopic hairs); help remove foreign particles 3. MALTs: (mucosal-something-lined-something) a general term for any mucus lined structure: tonsils, Peyer’s patches, appendix, and spleen Lymph nodes are found in groups or chains along paths of vessels throughout the body o The major areas you should be aware of are listed below but be careful of the name and its actual description . Cervical region: under the jaw (you can feel these with your fingers) . Axillary region: armpits . Inguinal and Pelvic regions: genital and pelvic areas Lymph and lymphocytes are produced in 2 key areas o Thymus: near base of heart (remember that’s the “top”); just above the aortic arch (looks like it sits on top of the arch) . T cells are produced here; most other lymphocytes are produced in bone marrow . T cells remain inactive as part of acquired immunity These are called on for specific pathogens; fight infections o Spleen: above the kidneys but below the diaphragm, lateral to stomach . Looks like a giant lymph node but filled with blood not lymph White pulp: look like tiny islands and packed with lymphocytes Red pulp: fills space between islands; mostly red blood cells and some lymphocytes . Main purpose is to removed cell debris and dead/old cells which ends up mixed in with the red blood cells Natural immunity vs acquired immunity Natural immunity – general; used to protect against a variety of pathogens; “every day” protection; cuts, scrapes, splinters, etc. o Uses “first-line” defenses; rapid 1. Skin or mucous linings 2. Phagocytes just below skin’s surface can engulf pathogens 3. Phagocytosis is “cell-eating” or when a cell engulfs other particles 4. Use proteins to further destruction Natural Defenses What is it? 1. Species Resistance 2. Mechanical Barriers 3. Chemical Barriers 4. NK Cells 5. Inflammation 6. Phagocytosis 7. Fever Acquired immunity – carried out by specialized lymphocytes o Happens slowly/overtime o Antigens (cells recognized as non-self) o Humoral immunity against antigens (fluid mediated) . Uses B cells, B memory cells, plasma cells, and antibodies . Most commonly fights bacterial infections o Cellular immunity (infected cells) . T cells, T memory cells, helper cells, and cytotoxic cells . Most commonly fights viral infections Acquired Defenses What is it? 1. Antigens/Antigen-presenting cells 2. T cells 3. B cells 4. Cytotoxic cells 5. Helper and Memory cells 6. Plasma Cells 7. Antibodies Steps in Antibody Production T Cell Activities Antigen (nonself) connects to an antigen-presenting cell (self) Antigen-presenting cell activates the T cells o Or B Cells (discussed further down) T cells interact directly with antigen and antigen-presenting cell o Interaction is called cellular immune response T cells produce cytokines (peptides that enhance cellular response) which trigger the release of B cells T helper cells tell B cells to produce antibodies for specific antigens o Cytotoxic cells (specialized T cells) target cancerous cells and virally infected cells o Cytotoxic cells give rise to T memory cells to further immunity B Cell Activities Antigen connects to antigen-presenting cell Antigen-presenting cell activates B cells o Usually requires T cells to activate them first If T cells encounter B cells interacting with antigen, it uses T helpers to make the B cells produce antibodies o Attracts macrophages to create a “closed” or isolated inflammation area o B cells can create plasma cells which also produce antibodies o This antibody-lead immune response is called humoral immune response o Only one type of B cell produces one type of antibody Antibodies: What are they and How Do They Work? Structure: 4 chains of amino acids linked together in a Y shape o 2 identical light chains o 2 identical heavy chains (heavy because they have more amino acids) They have a variable region which is used to match to antigens o The following parts connect together . Antigen-binding sites on the antibody . Idiotypes on antigens Antibodies react to antigens in 3 ways o Direct attack: antibodies attach to antigens and cause them to clump together so phagocytes can engulf them easier o Activate Complement: complements (proteins that bind to antigens) cover antigen-antibody complexes for easier phagocytosis o Inflammation: (a.k.a. stimulate localized changes) can damage tissues but prevents infection from spreading (edema caused by vasodilation and release of histamines) Primary and Secondary Immune Responses Primary: when B and T cells are activated after first encountering antigens o Travel through blood for many weeks and eventually create memory cells o Short-lived Secondary: when memory B and T cells are sued for viral infection and after initial infection o These live a long time in blood Bacteria Virus Shapes of cells Round, pill, spiral, and comma Spherical, helical, polyhedral, and complex Infection Uses toxins: microbes can release a toxin Inject its DNA into host cell, uses that poisons your body host cell’s DNA to copy itself, bursts Destroys tissues: produces enzymes that out of host cell to spread copies “digest” your tissues Treatment Antibiotics: chemicals that inhibit growth Vaccines: weakened form of of or kills microbes in an organism pathogen injected to prepare immune system to recognize and destroy pathogen Examples 1. 1. 2. 2. 3. 3. 4. 4. 5. 5. Allergic Reactions Immune response to non-harmful substance cause by: o Hypersensitivity o Inherited tendency o Triggered by specific antigens called allergens Immediate-reaction: occurs within minutes after first contact o Release of histamines, dilate arterioles, and increase vascular permeability = edema and constriction of bronchial (lungs) and intestinal smooth muscles o Hives, asthma, eczema, gastric disturbances o Anaphylactic shock . Very sudden and overwhelming feeling . Severe swelling of tongue, mouth, larynx (windpipe), and vomiting . Cure: needs injection of epinephrine (adrenaline) and sometimes a tracheotomy (direct incision into larynx) to restore breathing and decrease swelling Usually caused by insect stings and penicillin Other allergens cause a similar reaction but usually not as severe Hypersensitivities o Takes 1-3 hours to develop antibodies o Blocks vessels which damages tissues o Leads to autoimmunity = loss of ability to tolerate self-antigens Delayed-reactions o Happens to anyone; caused by repeated exposure . Chemicals (household and industrial) and cosmetics (makeup, soap, and lotions) o Due to build up on the skin which attracts T cells (takes about 48 hours) Autoimmunity Immune system fails to distinguish self from nonself o Produces autoantibodies (antibodies that attack own cells) as well as T cells and cytotoxic cells that attack tissues and organs Beginnings of autoimmunity are not well known and are still being studied; the following are some examples 1. Viruses infect a host cell and uses its DNA to “turn into” the host cell by mimicking the appearance of the host cell 2. Immune system figures out what the fake host cells looks like and forms antibodies for it but never fully differentiates self from nonself for the rest of your life 3. Nonself antigen reassembles as self; some infections naturally reassembles our cells and are changed into self-cells 4. In some women, fetal cells remain throughout life but hide until middle age; these cells turn into a genetically distinct cell population called a mosaic; begin to form hard patches on the skin and become an autoimmune disorder as self-cells try to fight of genetically distinct cells Transplant and Tissue Rejections The donor’s cells are recognized as foreign and are attacked or destroyed by recipient’s cells o Common with any transplant (bone, corneas, kidneys, lungs, pancreases, bone marrow, skin, livers, and hearts) o Resembles cellular immune response .
Recommended publications
  • Corpora Amylacea Act As Containers That Remove Waste Products from the Brain
    Corpora amylacea act as containers that remove waste products from the brain Marta Ribaa,b,c,1, Elisabet Augéa,b,c,1, Joan Campo-Sabariza,d, David Moral-Antera,d, Laura Molina-Porcele, Teresa Ximelise, Ruth Ferrera,d, Raquel Martín-Venegasa,d, Carme Pelegría,b,c,2, and Jordi Vilaplanaa,b,c,2 aSecció de Fisiologia, Departament de Bioquímica i Fisiologia, Universitat de Barcelona, 08028 Barcelona, Spain; bInstitut de Neurociències, Universitat de Barcelona, 08035 Barcelona, Spain; cCentros de Biomedicina en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain; dInstitut de Recerca en Nutrició i Seguretat Alimentàries (INSA-UB), Universitat de Barcelona, 08291 Barcelona, Spain; and eNeurological Tissue Bank of the Biobanc- Hospital Clinic-Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain Edited by Lawrence Steinman, Stanford University School of Medicine, Stanford, CA, and approved November 5, 2019 (received for review August 8, 2019) Corpora amylacea (CA) in the human brain are granular bodies 6). Nonetheless, we observed that CA contain glycogen synthase formed by polyglucosan aggregates that amass waste products of (GS), an indispensable enzyme for polyglucosan formation, and different origins. They are generated by astrocytes, mainly during also ubiquitin and protein p62, both associated with processes of aging and neurodegenerative conditions, and are located predom- elimination of waste substances (5). The relationship between CA inantly in periventricular and subpial regions. This study shows that and waste substances is recurrent in the literature. Already in 1999, CA are released from these regions to the cerebrospinal fluid and after a detailed and complete review, Cavanagh indicated that “CA are present in the cervical lymph nodes, into which cerebrospinal functions seem to be directed towards trapping and sequestration fluid drains through the meningeal lymphatic system.
    [Show full text]
  • Adaptive Immune Systems
    Immunology 101 (for the Non-Immunologist) Abhinav Deol, MD Assistant Professor of Oncology Wayne State University/ Karmanos Cancer Institute, Detroit MI Presentation originally prepared and presented by Stephen Shiao MD, PhD Department of Radiation Oncology Cedars-Sinai Medical Center Disclosures Bristol-Myers Squibb – Contracted Research What is the immune system? A network of proteins, cells, tissues and organs all coordinated for one purpose: to defend one organism from another It is an infinitely adaptable system to combat the complex and endless variety of pathogens it must address Outline Structure of the immune system Anatomy of an immune response Role of the immune system in disease: infection, cancer and autoimmunity Organs of the Immune System Major organs of the immune system 1. Bone marrow – production of immune cells 2. Thymus – education of immune cells 3. Lymph Nodes – where an immune response is produced 4. Spleen – dual role for immune responses (especially antibody production) and cell recycling Origins of the Immune System B-Cell B-Cell Self-Renewing Common Progenitor Natural Killer Lymphoid Cell Progenitor Thymic T-Cell Selection Hematopoetic T-Cell Stem Cell Progenitor Dendritic Cell Myeloid Progenitor Granulocyte/M Macrophage onocyte Progenitor The Immune Response: The Art of War “Know your enemy and know yourself and you can fight a hundred battles without disaster.” -Sun Tzu, The Art of War Immunity: Two Systems and Their Key Players Adaptive Immunity Innate Immunity Dendritic cells (DC) B cells Phagocytes (Macrophages, Neutrophils) Natural Killer (NK) Cells T cells Dendritic Cells: “Commanders-in-Chief” • Function: Serve as the gateway between the innate and adaptive immune systems.
    [Show full text]
  • Human Anatomy As Related to Tumor Formation Book Four
    SEER Program Self Instructional Manual for Cancer Registrars Human Anatomy as Related to Tumor Formation Book Four Second Edition U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service National Institutesof Health SEER PROGRAM SELF-INSTRUCTIONAL MANUAL FOR CANCER REGISTRARS Book 4 - Human Anatomy as Related to Tumor Formation Second Edition Prepared by: SEER Program Cancer Statistics Branch National Cancer Institute Editor in Chief: Evelyn M. Shambaugh, M.A., CTR Cancer Statistics Branch National Cancer Institute Assisted by Self-Instructional Manual Committee: Dr. Robert F. Ryan, Emeritus Professor of Surgery Tulane University School of Medicine New Orleans, Louisiana Mildred A. Weiss Los Angeles, California Mary A. Kruse Bethesda, Maryland Jean Cicero, ART, CTR Health Data Systems Professional Services Riverdale, Maryland Pat Kenny Medical Illustrator for Division of Research Services National Institutes of Health CONTENTS BOOK 4: HUMAN ANATOMY AS RELATED TO TUMOR FORMATION Page Section A--Objectives and Content of Book 4 ............................... 1 Section B--Terms Used to Indicate Body Location and Position .................. 5 Section C--The Integumentary System ..................................... 19 Section D--The Lymphatic System ....................................... 51 Section E--The Cardiovascular System ..................................... 97 Section F--The Respiratory System ....................................... 129 Section G--The Digestive System ......................................... 163 Section
    [Show full text]
  • The Size of Lymph Nodes in the Neck on Sonograms As a Radiologic Criterion for Metastasis: How Reliable Is It?
    AJNR Am J Neuroradiol 19:695–700, April 1998 The Size of Lymph Nodes in the Neck on Sonograms as a Radiologic Criterion for Metastasis: How Reliable Is It? Michiel W. M. van den Brekel, Jonas A. Castelijns, and Gordon B. Snow PURPOSE: A definition of cut-off points for nodal size is essential to determine whether cervical lymph nodes are metastatic or not. Because the currently used size criteria are defined for random populations of patients with head and neck cancer, we set out to study whether these criteria are optimal for patients without palpable metastases in different levels of the neck. We defined optimal size criteria for sonography by calculating the sensitivity and specificity of different size cut-off points. METHODS: We compared the sensitivity and specificity of different size cut-off points as measured on sonograms for various levels in the neck in a series of 117 patients with and 131 patients without palpable neck metastases. RESULTS: A minimum axial diameter of 7 mm for level II and 6 mm for the rest of the neck revealed the optimal compromise between sensitivity and specificity in necks without palpable metastases. For all necks together (with and without palpable metastases), the criteria were 1 to 2 mm larger. CONCLUSION: Our findings indicate that the current sonographic size criteria used for random patient populations are not optimal for necks without palpable metastases, nor can the same cut-off points be used for all levels in the neck. The management of lymph node metastases in the cious lymph nodes may convert both selective neck neck in patients with squamous cell carcinoma of the treatment and a wait-and-see policy to more secure upper air and food passages is a continuing source of comprehensive treatment of all levels of the neck (6).
    [Show full text]
  • Brain-To-Cervical Lymph Node Signaling After Stroke
    ARTICLE https://doi.org/10.1038/s41467-019-13324-w OPEN Brain-to-cervical lymph node signaling after stroke Elga Esposito1, Bum Ju Ahn1, Jingfei Shi1,2, Yoshihiko Nakamura 1,3, Ji Hyun Park1, Emiri T. Mandeville 1, Zhanyang Yu1, Su Jing Chan 1,4, Rakhi Desai1, Ayumi Hayakawa1, Xunming Ji2, Eng H. Lo1,5*& Kazuhide Hayakawa1,5* After stroke, peripheral immune cells are activated and these systemic responses may amplify brain damage, but how the injured brain sends out signals to trigger systemic inflammation remains unclear. Here we show that a brain-to-cervical lymph node (CLN) 1234567890():,; pathway is involved. In rats subjected to focal cerebral ischemia, lymphatic endothelial cells proliferate and macrophages are rapidly activated in CLNs within 24 h, in part via VEGF-C/ VEGFR3 signalling. Microarray analyses of isolated lymphatic endothelium from CLNs of ischemic mice confirm the activation of transmembrane tyrosine kinase pathways. Blockade of VEGFR3 reduces lymphatic endothelial activation, decreases pro-inflammatory macro- phages, and reduces brain infarction. In vitro, VEGF-C/VEGFR3 signalling in lymphatic endothelial cells enhances inflammatory responses in co-cultured macrophages. Lastly, surgical removal of CLNs in mice significantly reduces infarction after focal cerebral ischemia. These findings suggest that modulating the brain-to-CLN pathway may offer therapeutic opportunities to ameliorate systemic inflammation and brain injury after stroke. 1 Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA. 2 China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China. 3 Department of Emergency and Critical Care Medicine, Fukuoka University Hospital, Jonan, Fukuoka, Japan.
    [Show full text]
  • Magnetic Resonance Imaging Provides Evidence of Glymphatic Drainage
    www.nature.com/scientificreports OPEN Magnetic resonance imaging provides evidence of glymphatic drainage from human brain to Received: 25 October 2017 Accepted: 26 April 2018 cervical lymph nodes Published: xx xx xxxx Per Kristian Eide 1,2, Svein Are Sirirud Vatnehol 2,3, Kyrre Eeg Emblem3,4 & Geir Ringstad2,5 Pre-clinical research in rodents provides evidence that the central nervous system (CNS) has functional lymphatic vessels. In-vivo observations in humans, however, are not demonstrated. We here show data on CNS lymphatic drainage to cervical lymph nodes in-vivo by magnetic resonance imaging (MRI) enhanced with an intrathecal contrast agent as a cerebrospinal fuid (CSF) tracer. Standardized MRI of the intracranial compartment and the neck were acquired before and up to 24–48 hours following intrathecal contrast agent administration in 19 individuals. Contrast enhancement was radiologically confrmed by signal changes in CSF nearby inferior frontal gyrus, brain parenchyma of inferior frontal gyrus, parahippocampal gyrus, thalamus and pons, and parenchyma of cervical lymph node, and with sagittal sinus and neck muscle serving as reference tissue for cranial and neck MRI acquisitions, respectively. Time series of changes in signal intensity shows that contrast enhancement within CSF precedes glymphatic enhancement and peaks at 4–6 hours following intrathecal injection. Cervical lymph node enhancement coincides in time with peak glymphatic enhancement, with peak after 24 hours. Our fndings provide in-vivo evidence of CSF tracer drainage to cervical lymph nodes in humans. The time course of lymph node enhancement coincided with brain glymphatic enhancement rather than with CSF enhancement. In 2015, the traditional view of the brain having no lymphatic vessels was challenged by evidence showing func- tional lymphatic vessels lining the cranial dural sinuses in rodents1,2.
    [Show full text]
  • Multilingual Cancer Glossary French | Français A
    Multilingual Cancer Glossary French | Français www.petermac.org/multilingualglossary email: [email protected] www.petermac.org/cancersurvivorship The Multilingual Cancer Glossary has been developed Disclaimer to provide language professionals working in the The information contained within this booklet is given cancer field with access to accurate and culturally as a guide to help support patients, carers, families and and linguistically appropriate cancer terminology. The consumers understand their healthand support their glossary addresses the known risk of mistranslation of health decision making process. cancer specific terms in resources in languages other than English. The information given is not fully comprehensive, nor is it intended to be used to diagnose, treat, cure or prevent Acknowledgements any medical conditions. If you require medical assistance This project is a Cancer Australia Supporting people please contact your local doctor or call Peter Mac on with cancer Grant initiative, funded by the Australian 03 8559 5000. Government. To the maximum extent permitted by law, Peter The Australian Cancer Survivorship Centre, A Richard Pratt Mac and its employees, volunteers and agents legacy would like to thank and acknowledge all parties are not liable to any person in contract, tort who contributed to the development of the glossary. (including negligence or breach of statutory duty) or We particularly thank members of the project steering otherwise for any direct or indirect loss, damage, committee and working group, language professionals cost or expense arising out of or in connection with and community organisations for their insights and that person relying on or using any information or assistance. advice provided in this booklet or incorporated into it by reference.
    [Show full text]
  • Axillary Lymph Nodes and Breast Cancer
    AXILLARY LYMPH NODES Lymphatic system and axillary nodes The lymphatic system runs through the body. It carries lymph from tissues and organs to lymph nodes. Lymph nodes are small clumps of immune cells that act as filters for the lymphatic system. They also store white blood cells that help fight illness. The lymph nodes in the underarm are called axillary lymph nodes. If breast cancer spreads, this is the first place it’s likely to go. During breast surgery, some axillary nodes may be removed to see if they contain cancer. This helps determine breast cancer stage and guide treatment. Lymph node status is related to tumor size. The larger the tumor, the more likely it is the breast cancer has spread to the lymph nodes (lymph node-positive). Sentinel node biopsy To see if cancer has spread to the axillary lymph nodes, The lymphatic system runs through the body. most people have a sentinel node biopsy. Before or during the procedure, a radioactive substance (called a tracer) and/ or a blue dye is injected into the breast. The first lymph supraclavicular nodes nodes to absorb the tracer or dye are called the sentinel nodes. These are also the first lymph nodes where breast cancer is likely to spread. internal mammary The surgeon removes the sentinel nodes and sends them nodes to the lab. When the surgeon removes the sentinel nodes, it doesn’t mean there’s cancer in the nodes. It means a pathologist needs to check the nodes for cancer. If the nodes contain cancer, more lymph nodes may be removed.
    [Show full text]
  • Lymphatic Leukemia with Thymic Enlargement: a Brief Review of the Literature .With Case Reports
    LYMPHATIC LEUKEMIA WITH THYMIC ENLARGEMENT: A BRIEF REVIEW OF THE LITERATURE .WITH CASE REPORTS LLOYD F. CRAVER, M.D, AND WILLIAM S. MACCOMB, M.D. Memorial Hospital, New York Slight enlargement of the thymus may perhaps be present in lymphatic leukemia more frequently than is recorded in the litera- ture. This enlargement may be a true lymphosarcoma or thy- moma, or only a hyperplasia of lymphoid tissue. In a considerable series of cases a large sarcomatous tumor of the thymus with a leukemic blood picture has been the chief fea- ture, so that leukemia with involvement of the thymus came t.~be recognized as an atypical and malignant variety (1). These growt,hs have been designated by Orth as malignant leukemic lymphoma (2). As noted by Kaufmann (3), ('in leukemia, marked enlargement of the thymus gland is occasionally seen, especially in acute lym- phatic leukemia." The rapid growth of the thymus may be out of all proportion to the hyperplasia of other lymphatic structures and to the blood picture, thus giving rise to a mistaken diagnosis of thymoma as an entity. As stated by Heubner (4)) "with thymic tumors the other lesions of leukemia have not always been fully developed." Milne (5) in 1913 reported an unusual case of lymphatic leuke- mia which at autopsy revealed a mass of hyperplastic lymphoid tissue in the upper mediastinum, attached to the pericardium. This mass was ascribed to a hyperplasia of the anterior mediastinal lymph nodes and most probably the thymus, though no Hassall's corpuscles could be demonstrated. In 1925 Friedlander and Foote (6) reported a case of "malig- nant small-celled thymoma with acute lymphoid leukemia." Here the unripe lymph~blast~sof the blood stream so closely resembled the cells of the thymic tumor found at autopsy that the question arose-was the source of the abnormal cells of the blood an out- break of the tumor through the wall of some vein, or was the whole 277 278 LLOYD F.
    [Show full text]
  • NOTES: the Lymphatic / Immune System (Ch 12, Part 1) the Lymphatic System Is Closely Associated with the Cardiovascular System
    NOTES: The Lymphatic / Immune System (Ch 12, part 1) The lymphatic system is closely associated with the cardiovascular system. Functions of the Lymphatic System: ● transports excess fluid to the bloodstream ● absorbs fats ● helps defend the body against disease- causing agents LYMPHATIC PATHWAYS Lymphatic capillaries ● microscopic, closed-end tubes that extend into intercellular spaces ● receive LYMPH through their thin walls (LYMPH = the fluid of the lymphatic system … more later!) ● lymphatic capillary networks parallel blood capillary networks Lymphatic vessels: ● have walls similar to those of veins, but thinner, and have valves to prevent backflow of lymph ● become larger and lead to LYMPH NODES and then merge into LYMPHATIC TRUNKS Lymphatic Trunks and Collecting Ducts: ● lymphatic trunks lead to two collecting ducts: -THORACIC DUCT larger and longer duct ; receives lymph from the lower limbs, abdominal regions, left upper limb, left side of thorax, head, and neck -RIGHT LYMPHATIC DUCT receives lymph from the R side of the head & neck, R upper limb, R thorax ● collecting ducts join the SUBCLAVIAN VEINS Tissue Fluid & Lymph: ● LYMPH is essentially tissue fluid that has entered a lymphatic capillary ● tissue fluid originates from blood plasma and is composed of: -water -dissolved substances that leave blood capillaries (small molecules, nutrients, gases, hormones) **NOT present are larger plasma proteins (too large to pass through capillary walls) Functions of lymph: 1) returns to the bloodstream small proteins that leaked out
    [Show full text]
  • Chapter 21 the Lymphatic System
    Chapter 21 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 Introduction • The body harbors at least 10 times as many bacterial cells as human cells – Some beneficial – Some potentially disease-causing • Immune system—not an organ system, but a cell population that inhabits all organs and defends the body from agents of disease – Especially concentrated in the true organ system: lymphatic system • Network of organs and vein-like vessels that recover fluid • Inspect it for disease agents • Activate immune responses • Return fluid to the bloodstream 21-2 The Lymphatic System • Expected Learning Outcomes – List the functions of the lymphatic system. – Explain how lymph forms and returns to the bloodstream. – Name the major cells of the lymphatic system and state their functions. – Name and describe the types of lymphatic tissue. – Describe the structure and function of the red bone marrow, thymus, lymph nodes, tonsils, and spleen. 21-3 The Lymphatic System • Fluid recovery – Fluid continually filters from the blood capillaries into the tissue spaces • Blood capillaries reabsorb 85% • 15% (2 to 4 L/day) of the water and about half of the plasma proteins enter the lymphatic system and then are returned to the blood 21-4 The Lymphatic System • Immunity – Excess filtered fluid picks up foreign cells and chemicals from the tissues • Passes through lymph nodes where immune cells stand guard against foreign matter • Activates a protective immune response • Lipid absorption – Lacteals in small intestine absorb dietary lipids that are not absorbed by the blood capillaries 21-5 The Lymphatic System Copyright © The McGraw-Hill Companies, Inc.
    [Show full text]
  • The First Report of Bilateral Retropharyngeal Lymph Node
    Acta Oto-Laryngologica, 2011; 131: 1341–1348 CASE REPORT The first report of bilateral retropharyngeal lymph node metastasis from papillary thyroid carcinoma and review of the literature KAZUYUKI KAINUMA, RYOSUKE KITOH, HIDEKANE YOSHIMURA & SHIN-ICHI USAMI Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan Abstract The sites of lymph node metastasis of papillary thyroid carcinomas are typically the paratracheal and jugular lymph nodes. On the other hand, metastasis to the retropharyngeal or parapharyngeal nodes from papillary thyroid carcinomas is very rare. During the last two decades, limited to cases with a histologically definite diagnosis by surgery, only 39 cases have been reported. All reported cases were unilateral retropharyngeal or parapharyngeal node metastasis except one metachronous bilateral case, and there were no reports of simultaneous bilateral cases within our literature review. We report three cases of retropharyngeal node metastasis from thyroid papillary carcinoma, including a case of bilateral nodal metastasis. Retro- pharyngeal node metastasis was successfully resected in all three patients by the transcervical approach. As pointed out in past reports, this report also suggests that prior neck dissection and/or metastasis to cervical lymph nodes might alter the direction of lymphatic drainage to the retrograde fashion, resulting in the unusual metastasis to the retropharyngeal lymph nodes, and there is a possibility of a bilateral pattern. Also, it is necessary to consider the possibility of metastasis from a papillary thyroid carcinoma in the differential diagnosis of lymph node swelling in the parapharyngeal space. Keywords: Thyroid cancer, papillary carcinoma, parapharyngeal metastasis, neck dissection Introduction through the superior thyroid pole by way of the poste- rior lymphatic trunks, which are reported to be present Thyroid papillary carcinomas comprise 70–80% of in 20% of the cases [16].
    [Show full text]