Lymphatic System

Types of Immunity

Innate

Adaptive/non-specific

Phagocytes

  • Either patrol body like neutrophil or can stay in 1 place till told

Components of Defense

1st: Skin

3rd: Inflammation

2nd: Mucous Lining

Macrophages

Natural Killer Cells (NKC)

Antigens

Dendritic cells

  • Found in places that come in contact w/ outside (nose, lungs)

Any organism trying to enter body is stopped by our largest organ

Sticky, viscous fluid traps any pathogens trying to pass

Done by mast cells

  • Cells are constantly searching for suspicious objects in body
  • When things are found the release signal in form of histamine molecules
  • This alerts body & blood is rushed to problem area which causes inflammation & brings WBC's
  • "Big Bad News"
  • Engulf unwanted pathogens
    -Collected in certain places
  • Can consume about 100 pathogens before they die, but can also detect our own cells that have gone rogue(Cancer Cells) & kill them too
  • Traces that pathogens leave behind
  • Molecules found on surface of pathogens that can be detected by Adaptive for recognition
  • Dendric cells pass this info. to T-cells
  • Efficiently detect when our own cells have gone rogue or are infected w/ a virus
  • Detect a protein produced by normal cells called the Major Histocompatibility Complex(MHC)
  • When cell isn't normal it stops producing this protein
  • NKC'S move around constantly, checking cells for this deficiency
    when found of abnormal cell it binds to it & releases chemicals that will destroy it.

2 semi-independent parts:

  • Lymphatic vessels
  • Lymphatic tissue or organs

Function:

  • Return clean fluids & leaked protein back to the blood
  • Drain excess fluid from tissue
  • Play essential role in body defenses& resistiance to diseases

Characteristics

  • Lymph
    Materials returned to blood
  • Water
  • Blood cells
  • Proteins
    Harmful materials destroyed or removed:
  • Bacteria
  • Viruses
  • Cancer Cells
  • Cell debris(Dead cells)
    -1 way system to heart
    -No pump
    -Lymph moves to heart (by milking action of skeletal muscle surrounding vessels)

Lymphatic Organs

Lymph node

Lymphocyte
2 TYPES:

T(Thymus)

B(Bone Marrow)

Cause direct destruction of virus invaded cells & mutant cells

  • Involved in cell-mediated immunity

Secrete antibodies that indirectly lead to the destruction of foreign material

  • involved in humoral or antibody-mediated immunity
  • Encapsulated masses of lymphoid tissue that contain lymphocytes
  • Located: in areas vulnerable to pathogen
  • Monitor & filter lymph
  • Macrophages(Large)
    WBC's
  • Engulf & destroy foreign substances

Structure of lymph node

  • Kidney shaped; 1 inch long
  • lymph flow through sinuses
  • lymph goes to afferent lymphatic vessels & exits out efferent lymphatic vessels at hilus
  • Fewer efferent that afferent vessels
    Causes flow of lymph to be slowed for better filtration

Spleen

  • Located: left side of abdomen next to stomach
  • Filters blood
  • Destroys worn out cells
  • STORAGE OF BLOOD IN CASE OF EMERGENCY

Humoral Immune Response AKA Antibody-mediated Immunity

Fights infection and are located in various body fluids

  • Both B & T-cells have receptor proteins to bind to antigens
  • Each lymphocyte is designed to recognize a specific type of antigen

Primary Humoral Response

  • Most B cells become plasma cells which produce antibodies
    Antibodies travel through blood, lymph, & mucus to destroy pathogens
    Antibody activity lasts 4 to 5 days
  • Some B cells become long-lived memory cells for the secondary humoral response

Secondary Humoral Response

  • Reintroduction of the antigen at a future time
  • Reaction: Much faster, stronger, move efficient, & longer lasting than primary
  • Destroys pathogen before any symptoms of infections shows
  • Memory cells become activated & divide rapidly producing antibodies as soon as antigen is reintroduced into body

Active Immunity

  • Own body's B cells have to make antibodies & memory cells
  • 2 Types:
    Naturally acquired active: Making antibodies during an illness or infection in normal circumstances
    Artificially acquired passive: Receive injection of immune serum or antibodies