Lymphatic system and Immunity

Subclavian vein

Organs involved

The Thymus Figure 14-7(b) Create T-cells Release hormone thymosin to mature T-cells

The Spleen Figure 14-8(a) Biggest lymphatic organ Like a large lymph node, but spaces within the spleen is filled with blood instead of lymph. Contains lymphocytes.

Body Defense against Infection Body can prevent pathogens from entering the body or destroy pathogens when they enter the body. Types of defense: 1.Non-specific – General and protect against many types of pathogens. Always function the same way. For example: Mechanical barriers – skin, mucous membranes – 1 st Line of defense Chemical barriers (called 2 nd line of defense) Enzymes Tears Salt from sweat Fever Inflammation Interferons – produced in response to viruses or tumor cells Phagocytosis (White blood cells engulfing and ‘eating’ bacteria)

2. Specific Defenses = 3 rd line of defense Very precise in targeting specific pathogens with immunity. Antigens T – Cells B - Cells