lymphatic system

• Lymphatic system


  Protects the body from invaders, maintains the fluid level in the body, and absorbs dietary fat from the intestine
• Components of the lymphatic system

  • Lymph
  • Lymphocytes
  • Lymphatic vessels and plexuses
  • Lymph nodes
  • Other lymphoid organs
• Lymphoid organs


  • Thymus
  • Bone marrow
  • Lymph nodes
  • Spleen
  • Tonsils
• Lymphoid organs


  Part of the lymphatic system that are directly involved in the immune system because they produce lymphocytes
• Lymph formation


  1. Fluid leaks from capillary beds

  2. Fluid enters lymphatic capillaries

  3. Lymph travels through lymphatic vessels

  4. Lymph drains into lymphatic trunks

  5. Lymph drains into lymphatic ducts
• Lymph


  Clear or slightly yellow fluid transported through lymphatic vessels
• Lymphatic capillaries


  Small, porous capillaries that form lymphatic plexuses and take up fluid from the extracellular space
• Lymphatic vessels


  Drain lymph through lymph nodes and eventually into lymphatic trunks
• Lymphatic trunks


  Drain large regions of the body, like the subclavian trunks that drain the upper limbs
• Right lymphatic duct


  Collects lymph from the right side of the head and neck, the right side of the chest, and the right upper limb
• Thoracic duct


  Collects lymph from the left side of the head and neck, the left side of the chest, the left upper limb, the abdomen and both lower limbs
• Cisterna chyli


  Dilated sac where the lymphatic trunks carrying lymph from the lower limbs, abdominal viscera, and the pelvis converge
• Lymph from the right lymphatic duct and the thoracic duct drain into the superior vena cava to reach the right atrium of the heart
• Lymph nodes


  Filter the lymph and check for foreign invaders
• Major lymph node groups in the upper body

  • Cervical lymph nodes
  • Posterior mediastinal lymph nodes
  • Axillary lymph nodes
  • Cubital lymph nodes
• Major lymph node groups in the lower body

  • Lumbar lymph nodes
  • Iliac lymph nodes
  • Superficial and deep inguinal lymph nodes
  • Superficial and deep popliteal lymph nodes
• The lymphatic system absorbs dietary fat from the intestine, protects the body from foreign invaders, and maintains extracellular fluid volume by returning excess tissue fluid to the blood
• The lymphatic system consists of a network of lymphatic plexuses and vessels, lymph nodes, and other lymphoid organs such as the spleen and tonsils
• Lymph moves through lymphatic vessels and finally drains into the venous system through the thoracic duct and the right lymphatic duct