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