Lymphatic System Functions
-collects excess interstitial fluid and returns it to the bloodstream
-filters out foreign particles and produces white blood cells called lymphocytes to fight infection
Cortex
Outer part of lymph node, contains b cells and follicular denritic cells
Medulla
Inner part of lymph node, contain medullary cords with lymphocytes, plasma cells, and macrophages; linked by medullary sinuses
Lymph node function
Filters lymph by trapping bacteria, viruses, cancer cells, and other foreign substances present in the lymph . They also contain WBC’s.
Spleen
-Largest lymph organ
-removes old and damaged lymphocytes
-filters out pathogens and foreign particles from the blood
- Stores leukocytes and platelets, releasing them when needed
Thymus
-
-T-cell maturation site.
-Important in the immune systems identification of self and non self.
-Declines with age
Tonsils
-palatine, lingual, pharyngeal
-1st line of defense against inhaled/ingested pathogens
-contain immune cells that trap and kill invading microorganisms.
palatine tonsil location
Bilateral on throat
Lingual
Base of tongue
Pharyngeal
Roof of mouth
MALT (mucosa associated lymphoid tissue)
-Protects mucosal surfaces by initiating immune responses against pathogens that interact with mucous membranes
-Facilitates the interaction of antigens with immune cells to generate an adaptive response
Innate Immunity
- 1st line of defense, nonspecific response
- Physical barriers (skin, mucus membranes)
- Phagocytic cells (macrophages, neutrophils)
- inflammatory Response
- Rapid action
Adaptive Immunity
- Specific immune response tailored to specific pathogens
- Develops over time after exposure to antigen
- Includes memory cells that provide long-term immunity,
Humoral mediated immunity
- Mediated by B cells taht produce antibodies to neutralize pathogens
- Antibodies circulate in bodily fluids and bind to antigens, marking them for destruction
