Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: May 2 2021

Secondary Lymphoid Tissue

  • Introduction
    • Secondary lymphoid tissue has many important roles in immunity including
      • filtration and sampling of bodily fluids in order to detect infection
      • sequestration of pathogens and ingestion by innate immune cells
      • activation of adaptive immunity by antigen presenting cells
      • maintainance of immunological memory by storage of long lived cells
    • There are several types of secondary lymphoid tissue including the
      • spleen
        • a solid organ in the left upper quadrant of the abdomen
      • lymph nodes
        • a diffuse network of small nodes throughout the body
      • mucosal lymphoid tissue
        • patches of immunological tissue such as
          • Waldeyer's ring consisting of
            • tubular tonsils in the pharyngeal recess
            • palatine tonsils
            • lingual tonsils at the base of the tongue
          • Peyer patches in the lower jejunum and ileum
  • Spleen
    • The spleen is located in the left upper quadrant of the abdomen where
      • it is protected by the 9th to 11th ribs
      • it sits anterior to the left kidney
    • There are several components of the spleen, which are divided into
      • white pulp, which is the
        • the immunologically active part of the spleen containing
          • germinal centers containing
            • activated B-cells (part of a larger B-cell follicle)
          • periarteriolar lymphatic sheaths (PALS) containing
            • T-cells
          • marginal zones containing
            • macrophages and other antigen-presenting cells
      • red pulp, which is
        • the hematologically active part of the spleen characterized by
          • arterioles to allow for
            • delivery of red blood cells (RBCs)
          • resident macrophages to ingest both
            • dying/abnormal RBCs and encapsulated bacteria
          • sinusoids with a fenestrated basement membrane to
            • allow for red RBC exit
    • There are many clinical manifestations of asplenia including
      • increased susceptibility to infections by encapsulated bacteria
      • appearance of abnormal RBC forms on peripheral blood smear
      • others described more fully in the asplenia topic
  • Lymph Nodes
    • Lymph nodes are a diffuse network of encapsulated lymphoid tissue that
      • have many regional afferent lymphatic vessels
      • have at least one efferent lymphatic
    • There are several components of a lymph node, which are divided intothe
      • cortex
        • an outermost layer of the lymph node that is composed of
          • follicles composed of proliferating B cells that can be
            • dormant and cell dense primary follicles
            • active and pale secondary follicles
              • germinal centers where isotype switching occurs
            • underdeveloped in patients with X-linked agammaglobulinemia
          • subcapsular macrophages that monitor incoming lymph
          • dendritic cells that serve as antigen presenting cells
      • paracortex
        • an intermediate layer of the lymph node that is composed of
          • high endothelial vessels (HEVs) where
            • lymphocytes enter lymph nodes
          • T-cells that await activation, meaning that this region is
            • hypertrophied in infections triggering cellular immunity
            • underdeveloped in patients with DiGeorge syndrome
      • medulla
        • an innermost layer of the lymph node that is composed of
          • cords with closely packed lymphocyte and plasma cell "cords"
          • sinuses that drain into the efferent lymph vessels and house
            • reticular cells
            • macrophages
  • Lymph Node Drainage Pattern
      • Lymph Node Drainage Pattern
      • Lymph Node Cluster
      • Drainage Area
      • Cervical
      • Head
      • Neck
      • Hilar
      • Lungs
      • Mediastinal
      • Trachea
      • Esophagus
      • Axillary
      • Upper limb
      • Breast
      • Skin above the umbilicus
      • Celiac
      • Liver
      • Stomach
      • Spleen
      • Pancreas
      • Upper duodenum
      • Superior mesenteric
      • Lower duodenum
      • Jejunum
      • Ileum
      • Colon proximal to splenic flexure
      • Inferior mesenteric
      • Colon between splenic flexure and upper rectum
      • Internal iliac
      • Lower rectum
      • Anal canal proximal to pectinate line
      • Bladder
      • Cervix
      • Prostate
      • Paraaortic
      • Testes
      • Ovary
      • Kidney
      • Uterus
      • Superficial inguinal
      • Anal canal distal to pectinate line
      • Skin below the umbilicus
      • Scrotum
      • Vulva
      • Popliteal
      • Dorsolateral foot
      • Posterior calf
1 of 0
1 of 4
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options