Module 2 lymphatic system Flashcards
3 Functions of lymphatic system
1 - part of immune system (fights pathogens)
2 - Returns excess fluids to the blood
3 - Absorbs lipids in the digestive tract
Lymph
- fluid in the lymphatic vessels
- interstitial fluid collected through lymph capillaries
Lymph vessels
- these begin as lymph capillaries
- resemble veins
Lymph capillaries
- act as filters to trap foreign substances
- in the small intestine the are called lacteals
Lymph nodes
- act as filters to trap foreign substances
- encapsulated masses of B and T cells
- many in head, neck & abdomen
Lymph nodules
- non capsulated masses of lymph tissue
- contain B and T cells
- found in mucous membranes
Lymphocytes
2 types:
- B cells
- T cells
B cells
- Origination & maturation
- Immune response responsible for
- What does it do
- Created in Red bone marrow
- Stays in Red bone marrow & matures there
- Antibody-mediated response
- secretes antibodies
- when activated - becomes plasma cells
- attacks antigens found outside body cells
- produces memory cells
T cells
- Origination & maturation
- Immune response responsible for
- 2 types
- What does it do
- Created in Red bone marrow
- Matures in thymus
- Cell-mediated response
- Helper T (CD4) & Cytotoxic T (CD8)
- Attack invaders directly
- attack antigen found INSIDE body cells
Thymus gets ______ with age.
SMALLER
Most important in infancy when no immunity has developed - shrinks considerably by teens.
Specific Immune response
- Antigen-antibody response
- destruction of a foreign object by a cytotoxic T lymphocyte
- adaptive response
- activated by non-specific response
Non-specific immune response
- Innate defenses; present at birth
- physical barriers: skin etc
- Inflammation
- Phagocytosis
- Interferon - produced by lymphocytes infected with a virus
- Fever
- Chemicals; lysozyme, sweat, sebum
- NK cells; releases perforin to destroy cell
Inflammation
- Vasodilation & increased permeability of capillaries allows more blood flow, antibodies & clotting factors to injured area.
- Emigration of phagocytes: w/in 1 hour phagocytes arrive - neutrophils begin to stick to endothelium of blood vessel - squeeze thru wall to damaged area
- tissue repari = hemostasis
Specific Immunity Types
Intracellular/extracellular
- Cell-mediated: Tcells
- Antibody-mediated: B cells
Antigen
- a foreign substance
- provokes an immune response
Antibodies
- a protein produced by plasma cells in response to specific antigens (immunoglobins).
- combines with antigens to destroy it.
MHC Antigens
- Major Histocompatibility Complex
- self-antigens (marks it as yours)
- used in tissue typing
Cell-mediated response
general response
- Adaptive Immunity
- Intracellular (inside cells)
- Main lymphocyte = Cytotoxic T cells
- directly attacks invading antigens
- faster response
Antibody-mediated response
general response
- humoral immunity
- Extracellular
- B cells transform into plasma cells which then secrete anti-bodies
- Antibodies bind to specific antigens & destroy them
3 major types of Lymphocytes
- B cells
- T cells
- NK cells (natural killer)
Cell mediated immune response STEPS 1 - recognition 2 - activation & proliferation 3 - Attack
1- Naive T cell meets threat (detection)
2- Co-stimulation - Activation of Helper T
- Differentiation - Active & Memory T’s
-Secretion of Cytotoxic T’s
3- Active effector T cells attack target cells
Antibody mediated immune response STEPS 1 - recognition 2 - activation & proliferation 3 - Attack
1-Hangs out in lymphatic tissues until activated
2- Antigen bind to Bcell receptors
-Helper T co-stimulates B cells which then differentia into Plasma cells & Memory cells
3- Plasma cells secrete antibodies
-go to invasion
-antibodies bind to antigen & destroy it.
Memory cell
- remember the antigen
- formed by activation of B-cell
- involved in Antibody mediated immunity
- involved in cell mediated immunity
Helper T-cell
- CD4 cells
- stimulates proliferation of both B & cytotoxic T cells
- mediator of Secondary immune response
Cytotoxic T-cell
- in cell-mediated immunity
- CD8 cells
- Killer T-cells
- destroys antigens by disrupting plasma membrane (perforin)
- releases cytokines to attrack macrophages to attack.
Plasma Cell
- formed from activation of B cells
- Secretes antibodies
- involved in Antibody mediated immunity
Macrophage
- involved in Antibody mediated immunity
- involved in cell mediated immunity
- phagocyte which engulfs & displays antigens on its surface
NK cells
- cytotoxic lymphocyte critical to the innate immune system
- can recognize foreign cells in the absence of antibodies and MHC
- faster immune reaction.
- do not require activation in order to kill cells that are missing “self” markers of major histocompatibility complex (MHC) class 1
Intracellular pathogens
Viruses
-uses our cells to create itself
Extracellular pathogens
- Bacteria
- Fungi
- Protozoa
- Parasitic Worms
2 parts of Immune system
1 - Innate
2 - Adaptive
Innate Immunity
- born with it
- non-specific
- 1st & 2nd line of defense
Adaptive Immunity
- created throughout life
- Specific
- 3rd line of defense
1st line of Defense
- Innate
- Physical Barrier (skin)
- Chemical Barriers (salt, sweat, sebum)
2 line of defense
- Innate
- Cells (WBC’s) & Chemical protection
3rd line of defense
- adaptive
- lymphocytes: B & T cells
- Humoral: Antibody-mediated response
- Cellular: Cell-mediated response
IgA immunoglobulins
- found in tears, saliva, mucous
- provide protection in mucous membranes
IgE
- inflammation
- smallest group
IgG
- crosses placenta
- largest group
- resistant to many viruses & bacteria
- anti-Rh antibodies
IgM
-antibodies associated with ABO blood groups
IgD
-attach to B cells - plays a role in activation of B cell to plasma cell
Active immunity
- engages bodies immune response
- creates memory cells
Passive immunity
-no activation of bodies immune response
Natural Active
Get sick & recover
Artificial Active
Vaccinations
Natural Passive
- mom to fetus thru placenta
- mom to baby thru breastmilk
- temporary
Artificial Passive
- gamma globulin (injected)
- example is treatment of rabies
- temporary
