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George Velis Period 3 Lymphatic/Immune System - Coggle Diagram
George Velis Period 3 Lymphatic/Immune System
Major functions of the Lymphatic & Immune system
Maintains fluid balance:
excess interstitial fluid is collected and returned to the bloodstream, preventing tissue swelling
Absorbs dietary fats:
lacteals in the small intestine absorb fats and fat-soluble vitamins
Defense against pathogens:
immune system identifies and destroys bacteria, viruses, and abnormal cells
Immune surveillance:
lymph is filtered to detect antigens before they spread
Supports circulation:
works alongside cardiovascular system to maintain homeostasis
Location of Lymphatic organs and their function
Lymph nodes:
located along lymph vessels; filter lymph and house lymphocytes that respond to infection
Spleen
: located in the upper left abdomen; filters blood, removes damaged red blood cells, and stores immune cells
Thymus
: behind the sternum; site where T lymphocytes mature and learn self vs. non-self
Tonsils
: located in the pharynx; trap pathogens entering through mouth and nose
Bone marrow:
produces all blood cells including B cells and T cell precursors
Lymphatic vessels:
one-way vessels that transport lymph back to the heart
Purpose and examples of First, Second and Third line of defense
First Line of Defense (Physical & Chemical Barriers)
Prevents pathogens from entering the body
Includes skin, mucous membranes, saliva, tears, and stomach acid
Second Line of Defense (Innate Internal Defenses)
Activated once pathogens enter the body
Includes inflammation, fever, phagocytes, and antimicrobial proteins
Third Line of Defense (Adaptive Immune Response)
Specific defense against particular pathogens
Involves lymphocytes, antibodies, and memory cells
Innate(natural) immune defenses and Adaptive(acquired) immune defense
Innate Immunity
Present at birth and always active. Responds quickly and non-specifically. Includes inflammation, fever, and phagocytosis
Adaptive Immunity
Develops after exposure to specific antigens. Slower initial response but highly specific. Creates memory cells for faster future responses
Humoral response and cellular response
Humoral (Antibody-Mediated) Response
Involves B lymphocytes. B cells differentiate into plasma cells that secrete antibodies. Targets pathogens circulating in blood and lymph
Cellular (Cell-Mediated) Response
Involves T lymphocytes. Cytotoxic T cells destroy infected or abnormal body cells. Important for viral and cancer cell defense
Antigens and antibodies
Antigens
: foreign molecules (proteins, sugars) that trigger an immune response. Usually proteins on bacteria, viruses, or cancer cells. Recognized as foreign by the immune system. Activate immune cells and antibody production
Antibodies
: Y-shaped proteins produced by B cells. Bind specifically to antigens. Neutralize toxins, mark pathogens for destruction, and activate complement. Types include IgG, IgA, IgM, IgE, and IgD
Antigen-antibody binding
: highly specific interaction
Passive vs. Active immunity
Active Immunity
Individual’s immune system produces antibodies. Develops after infection or vaccination. Long-lasting and creates memory cells
Passive Immunity
Antibodies are received from another source. Provides immediate but temporary protection. Ex. breast milk and antivenom
Cells involved in the immune system and their functions
Neutrophils
: most abundant phagocytes; first responders; engulf bacteria and die after infection
Macrophages:
powerful phagocytes derived from monocytes; engulf pathogens and present antigens
Dendritic cells
: antigen-presenting cells; activate T cells; initiate adaptive immunity
Natural killer cells:
kill virus-infected cells without prior exposure
Lymphocytes
: adaptive immune cells responsible for antibody production and immune memory
Plasma cells:
activated B cells that secrete large amounts of antibodies
Helper T cells (CD4⁺):
coordinate immune response; activate B cells and cytotoxic T cells
Cytotoxic T cells (CD8⁺):
destroy infected and abnormal cells
Regulatory T cells:
suppress immune response; prevent autoimmunity
Memory B & T cells:
provide long-term immunity and rapid secondary response
Disorders associated with the Immune system
Tapeworm (Taeniasis)
: parasitic infection affecting GI tract, muscles, and nervous system; symptoms include abdominal pain and diarrhea; treated with antiparasitic drugs and hygiene
COVID-19:
viral infection affecting respiratory and multiple organ systems; symptoms include fatigue and loss of taste/smell; prevented by vaccines and hygiene
Jock itch:
fungal infection of warm, moist areas; causes itching and rashes; treated with antifungal medications
Viral meningitis:
inflammation of meninges; causes headaches and fever; treated with supportive care and vaccines
Athlete’s foot:
fungal skin infection; causes itching and peeling; treated with antifungal creams and hygiene
Artificial vs. Naturally acquired immunity
Naturally Acquired Immunity
Occurs through infection and recovery. Includes maternal antibodies passed through placenta or breast milk
Active
: infection causes body to produce antibodies and memory cells
Passive
: antibodies transferred naturally (mother to baby); temporary protection
Artificially Acquired Immunity
Produced through medical intervention. Includes vaccinations and injected antibodies
Active
: vaccination stimulates antibody and memory cell production
Passive
: injection of pre-made antibodies; immediate but temporary protection