Skip to main content
뒤로

Lymphatics and Innate Immunity - Anatomy & Physiology

컨트롤 버튼이 '내비게이션' 모드로 변경되었습니다.
1/27

이 집합의 용어 (27)

  • What are the three main components of the lymphatic system?
    Network of lymphatic vessels, lymph fluid, and lymph nodes that cleanse lymph.
  • What is the primary function of lymphatic vessels?
    Return interstitial fluid and leaked plasma proteins back to the blood, about 3 liters per day.
  • What are lymphatic capillaries and how do they differ from blood capillaries?
    Blind-ended tubes with overlapping endothelial cells forming one-way minivalves; very permeable and anchored by collagen filaments.
  • Where are lymphatic capillaries absent?
    Absent from bones, teeth, bone marrow, and the central nervous system.
  • What are lacteals and their function?
    Specialized lymphatic capillaries in the intestinal mucosa that absorb digested fats and deliver fatty lymph (chyle) to the blood.
  • Name the major lymphatic trunks.
    Paired lumbar, bronchomediastinal, subclavian, jugular trunks, and a single intestinal trunk.
  • What are the two main lymphatic ducts and their drainage areas?
    Right lymphatic duct drains right upper arm and right side of head and thorax; thoracic duct drains the rest of the body.
  • How is lymph propelled through lymphatic vessels?
    By skeletal muscle contractions, thoracic pressure changes during breathing, valves preventing backflow, arterial pulsations, and smooth muscle contractions in vessel walls.
  • What are the two main types of lymphocytes and their roles?
    T cells moderate immune responses and destroy infected cells; B cells produce plasma cells that secrete antibodies.
  • What is the role of macrophages in the lymphatic system?
    Phagocytize foreign substances and help activate T cells.
  • What is the structure and function of lymph nodes?
    Encapsulated organs with cortex and medulla; filter lymph by macrophages and activate lymphocytes to mount immune responses.
  • Describe the circulation of lymph through a lymph node.
    Lymph enters via afferent vessels, flows through sinuses to medulla, and exits via fewer efferent vessels, allowing immune cells time to act.
  • What are the main functions of the spleen?
    Lymphocyte proliferation, blood cleansing of aged cells, storage of iron and platelets, and possible fetal erythrocyte production.
  • How does the thymus differ from other lymphoid organs?
    No B cells or follicles; functions strictly in T cell maturation and is most active during childhood.
  • What is MALT and where is it found?
    Mucosa-associated lymphoid tissue; lymphoid tissues in mucous membranes like tonsils, Peyer's patches, and appendix.
  • What are the two lines of defense in the innate immune system?
    First line: external body membranes (skin and mucosae); second line: antimicrobial proteins, phagocytes, natural killer cells, inflammation, and fever.
  • What are the cardinal signs of acute inflammation?
    Redness, heat, swelling (edema), pain, and impairment of function.
  • What triggers the inflammatory response?
    Chemicals like histamine released by mast cells and injured tissues that cause vasodilation and increased capillary permeability.
  • Describe the process of phagocytosis.
    Phagocyte adheres to pathogen, engulfs it into a phagosome, fuses with lysosome to form phagolysosome, digests the pathogen, and expels residual material.
  • What are natural killer (NK) cells and their function?
    Lymphocytes that attack cells lacking 'self' markers, inducing apoptosis in cancer and virus-infected cells, and enhance inflammation.
  • What are interferons and their role in innate immunity?
    Proteins secreted by virus-infected cells that warn neighboring cells to produce antiviral proteins and activate NK cells.
  • What is the complement system and its functions?
    A group of ~20 blood proteins that enhance inflammation, promote phagocytosis, and cause cell lysis of pathogens.
  • Name the three pathways of complement activation.
    Classical (antibody-mediated), lectin (lectin binding to sugars), and alternative (spontaneous activation).
  • What is the membrane attack complex (MAC)?
    A complex of complement proteins (C5b-C9) that forms pores in target cell membranes causing lysis.
  • What is opsonization in immune defense?
    Coating of pathogens by complement proteins or antibodies to enhance phagocytosis.
  • What is leukocytosis and its role in inflammation?
    An increase in white blood cells released from bone marrow to fight infection during inflammation.
  • Explain the steps of phagocyte mobilization during inflammation.
    Leukocytosis, margination (adhesion to capillary walls), diapedesis (migration through capillaries), and chemotaxis (movement toward chemical signals).