Lymphatic System and Immunity

Lymphatic System Overview

• Function: Reclaims interstitial fluid, filters lymph, and supports immune response.

Fluid Pathway

• Water cycles in the body: Blood → Tissues (via capillary beds) → Lymphatic system → Back to Blood.
• Fluids:
  • Blood Plasma
  • Interstitial Fluid
  • Lymph

Lymphatic System Details

• Purpose: Filters debris and houses lymphocytes for immune defense.
• Edema: Results from impaired fluid movement, treatment needed for fluid redistribution.

Lymph Node Anatomy

• Structure: Multiple inlets and outlets; contain MALT (mucosa-associated lymphoid tissue).
• Location of Lymph Nodes: Common in neck, armpits, groin, etc.

Immune System Overview

• Nonspecific Immunity: General defenses (e.g., leukocytes, natural barriers).
• Specific Immunity: Targeted response via T cells (destroy infected cells) and B cells (produce antibodies).

Antigen Interaction

• Antigens trigger specific immune responses; specific T/B cells are activated upon first exposure.
• Memory cells allow for quicker response upon re-exposure to the same pathogen.

Vaccine Function

• Vaccines introduce antigens for safe initial immune response without risking severe illness.

Spleen and Thymus

• Spleen: Largest lymph organ; filters blood, recycles old red blood cells.
• Thymus: Site for T cell maturation, located anterior to the aorta.