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Lymphatic system Giselle Gonzalez P.3 - Coggle Diagram
Lymphatic system Giselle Gonzalez P.3
Major Functions of the Lymphatic & Immune Systems
Returns excess interstitial fluid to bloodstream
Maintains fluid balance
Absorbs fats from small intestine
Transports lymph throughout body
Protects against pathogens (bacteria, viruses, fungi, parasites)
Removes damaged or abnormal cells
Location of Lymphatic Organs & Their Functions
Bone marrow
→ produces white blood cells (B cells mature here)
Thymus
→ T cells mature here
Lymph nodes
→ filter lymph, trap pathogens, activate immune cells
Spleen
→ filters blood, removes old red blood cells, stores platelets
Tonsils
→ protect against inhaled/ingested pathogens
First, Second, and Third Lines of Defense
First Line (Physical/Chemical Barriers)
Skin
Mucous membranes
Saliva
Tears
Stomach acid
Prevent pathogens from entering body
Second Line (Innate Internal Defenses)
Inflammation
Fever
Phagocytic white blood cells (macrophages, neutrophils)
Natural killer (NK) cells
Nonspecific response
Third Line (Adaptive Immunity)
B cells
T cells
Antigen-specific response
Stronger, faster response upon re-exposure
Innate (Natural) vs. Adaptive (Acquired) Immunity
Innate Immunity
Present at birth
Immediate response
Nonspecific
No memory
Adaptive Immunity
Develops after exposure
Specific to antigen
Slower initial response
Forms memory cells
Faster secondary response
Humoral vs. Cellular Response
Humoral Response
Involves B cells
Produces antibodies
Targets pathogens in body fluids
Antibodies bind to antigens
Cellular Response
Involves T cells
Cytotoxic T cells kill infected cells
Helper T cells activate other immune cells
Targets infected or abnormal body cells
Antigens and Antibodies
Antigens
Foreign substances (proteins on pathogens)
Trigger immune response
Antibodies
Proteins made by B cells
Bind specifically to antigens
Neutralize or mark pathogens for destruction
Artificial vs. Naturally Acquired Immunity
Naturally Acquired
Develops after infection
Body produces own antibodies
Artificially Acquired
Through vaccination
Introduces weakened/inactive antigens
Stimulates immune response without disease
Passive vs. Active Immunity
Active Immunity
Body produces its own antibodies
Long-lasting protection
Infection or vaccination
Passive Immunity
Antibodies received from another source
Temporary protection
Breast milk or antibody injections
Cells of the Immune System & Their Functions
Macrophages → engulf pathogens (phagocytosis)
Neutrophils → first responders, destroy bacteria
B cells → produce antibodies
Helper T cells → activate B cells & cytotoxic T cells
Cytotoxic T cells → kill infected cells
Natural killer cells → kill infected or cancer cells
Dendritic cells → present antigens to T cells
Disorders of the Immune System
Hepatitis B
Viral infection that affects the liver
Caused by the hepatitis B virus (HBV)
Can become chronic and damage liver cells
Preventable through vaccination
Tuberculosis (TB)
Bacterial infection caused by Mycobacterium tuberculosis
Primarily affects the lungs
Spread through airborne droplets
Can remain dormant or become active
Jock Itch
Fungal infection of the skin
Caused by dermatophyte fungi
Affects warm, moist areas of the body
Causes itching, redness, and rash
Ringworm
Fungal skin infection (not caused by a worm)
Caused by dermatophyte fungi
Produces circular, red, itchy rash
Can spread through direct contact