Tag Archives: Mexican Hairless Dog

The Lymphoid System

The Lymph Nodes In dogs, the primordial structure of the largest lymph nodes is present at 35 to 38 days of gestation, and lymphocytic colonization of the nodes is prominent at 52 to 53 days of gestation (). At birth, puppies and kittens have readily recognizable lymph nodes with a loose reticular structure, low lymphocyte density, and limited organization into cortex and medulla that rapidly proliferates into cortical nodules and medullary cords. Lymph nodes and lymphatic vessels vary in location and number, but their primary function is to participate in immunologic reactions by filtering lymph and recirculating the lymphocytes (). Antigens that gain access to particular body tissues are ultimately found in lymphatic vessels that drain these tissues, making it logical that elements of the immune system are strategically positioned along lymphatic vessels. Although lymph node architecture is relatively uniform throughout the body, nodes near portals of entry of external antigens (mandibular and mesenteric lymph node areas) are often more reactive than nodes in other locations. Lymph Node Disorders As a major site of immunologic recognition, lymph nodes are expected to respond to various local and systemic inflammatory, Read more […]