Lymph Node Structure and Function
26 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of the spleen?

  • To filter lymph and remove debris
  • To produce lymphocytes
  • To filter blood and remove debris (correct)
  • To store platelets and RBCs

    • What is the role of Peyer's patches in the lymphatic system?

  • To act as a sentinel to protect the digestive tract (correct)
  • To act as a sentinel to protect the respiratory tract
  • To filter blood and remove debris
  • To produce lymphocytes

    • What is the function of the medulla in a lymph node?

  • To produce antibodies
  • To filter lymph and remove debris
  • To contain follicles with lymphocytes
  • To contain phagocytic macrophages (correct)

    • What is the function of the cortex in a lymph node?

    <p>To contain follicles with lymphocytes</p> Signup and view all the answers

    What happens to the flow of lymph through a lymph node?

    <p>It slows down due to fewer efferent vessels</p> Signup and view all the answers

    What can happen to lymph nodes when large amounts of bacteria or viruses are present?

    <p>They become inflamed and tender to touch</p> Signup and view all the answers

    What is the role of the spleen in relation to red blood cells?

    <p>It destroys worn out red blood cells and recycles some products</p> Signup and view all the answers

    What type of lymphoid tissue is the spleen?

    <p>A solitary lymphoid organ</p> Signup and view all the answers

    What is the main function of tonsils?

    <p>To trap and remove bacteria and other foreign materials</p> Signup and view all the answers

    What is the function of macrophages in Peyer's patches?

    <p>To capture and destroy bacteria</p> Signup and view all the answers

    At what stage of life does the thymus function at its peak levels?

    <p>Childhood</p> Signup and view all the answers

    What is lymphopoiesis?

    <p>The production of lymphocytes</p> Signup and view all the answers

    What is the role of thymosin?

    <p>To stimulate maturation of T cells</p> Signup and view all the answers

    What percentage of circulating leukocytes are lymphocytes?

    <p>20-40%</p> Signup and view all the answers

    What are the three classes of lymphocytes?

    <p>T cells, B cells, NK cells</p> Signup and view all the answers

    What happens to T cells after they mature in the thymus?

    <p>They enter the bloodstream and travel to the red bone marrow and peripheral tissues</p> Signup and view all the answers

    What is the main function of the lymphatic system?

    <p>To transport escaped fluids back to the blood and play essential roles in body defense</p> Signup and view all the answers

    What happens to the interstitial fluid that remains behind in the tissue spaces?

    <p>It develops into edema if not returned to the plasma</p> Signup and view all the answers

    What is the characteristic of lymphatic capillaries that allows them to push fluid only towards the heart?

    <p>Their overlapping endothelial cells</p> Signup and view all the answers

    What is the mechanism by which lymph flows towards the heart?

    <p>Milking action of skeletal muscle and rhythmic contraction of smooth muscle in vessel walls</p> Signup and view all the answers

    What is the characteristic of larger lymphatic vessels?

    <p>They contain a greater number of valves</p> Signup and view all the answers

    What is the function of lymph nodes?

    <p>To filter lymph and remove pathogens</p> Signup and view all the answers

    What is the term for the fluid carried by lymphatic vessels?

    <p>Lymph</p> Signup and view all the answers

    What is the difference between lymphatic vessels and blood vessels?

    <p>Lymphatic vessels have lower pressure</p> Signup and view all the answers

    What is the consequence of edema?

    <p>It hampers the cells' ability to exchange substances with the interstitial fluid and blood</p> Signup and view all the answers

    What is the function of the lymphatic system in body defense?

    <p>To filter out pathogens and foreign substances</p> Signup and view all the answers

    Study Notes

    Lymph Node Structure

    • Lymph nodes are kidney-shaped and less than 1 inch long, buried in connective tissue
    • The cortex is the outer part of the lymph node, containing follicles with collections of lymphocytes
    • The medulla is the inner part of the lymph node, containing phagocytic macrophages

    Flow of Lymph Through Nodes

    • Lymph flows through afferent lymphatic vessels, then sinuses inside the node, and finally efferent lymphatic vessels
    • There are fewer efferent than afferent vessels, slowing the flow of lymph
    • Lymph nodes can become inflamed and tender to touch if large amounts of bacteria or viruses become trapped

    MALT (Mucosa-Associated Lymphoid Tissue)

    • Includes Peyer's patches, tonsils, and other small accumulations of lymphoid tissue
    • Acts as a sentinel to protect respiratory and digestive tracts

    Other Lymphoid Organs

    • Spleen:
      • Filters blood rather than lymph
      • Destroys bacteria, viruses, and other debris
      • Destroys worn out RBCs and recycles some products, including iron
      • Stores platelets and RBCs, which can be released during hemorrhage
      • Can be removed, but increases the risk of infection
    • Tonsils:
      • Small masses of lymphoid tissue around the pharynx
      • Trap and remove bacteria and other foreign materials
    • Peyer's patches:
      • Found in the wall of the small intestine
      • Resemble tonsils in structure
      • Macrophages capture and destroy bacteria in the intestine
    • Thymus:
      • Located in the upper mediastinum thoracic cavity
      • Functions at peak levels only during childhood, shrinking by puberty
      • Site of T-cell maturation
      • Secretes thymosin

    Lymphopoiesis

    • Lymphopoiesis is the production of lymphocytes
    • Involves red bone marrow, thymus, and peripheral lymphoid tissues
    • Thymosin stimulates maturation of T cells, which reenter the bloodstream when near mature and travel to red bone marrow and peripheral tissues

    Lymphocytes

    • Account for 20-40% of circulating leukocytes
    • Circulating lymphocytes are a small fraction of the total lymphocyte population
    • There are three classes of lymphocytes: T cells, B cells, and NK cells

    The Immune System

    • Consists of two semi-independent parts: lymphatic vessels and lymphoid tissues and organs
    • Lymphatic system functions: transports escaped fluids back to the blood and plays essential roles in body defense and resistance to disease

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the structure and function of lymph nodes, including their location, cortex, and medulla, as well as the flow of lymph through nodes.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser