Lymphatic and Immune Systems Flashcards
Lymphocytes are not what kind of cells?
phagocytes
What are the most common cells in the lymphatic system?
lymphocytes
Lymphocytes are what kind of leukocyte?
agranulocytes
What is the function of lymphocytes?
Fight pathogens
Lymphocytes in general have what kind of immunity?
adaptive immunity
What are the three main types of lymphocytes?
T cells, B cells, and Natural killer cells
The T in T cells stands for what?
thymus
T cells are “___________ dependent.”
thymus
T cells are produced in __________________, but mature in ___________.
red bone marrow, thymus
What are the most common type of lymphocyte?
T cells
What are the two main types of T cells and their functions?
- Helper T: helping things/facilitating/giving order
- Cytotoxic T/Killer T cells: kill other cells
The B in B cells stands for what?
bone marrow
B cells are “_____________ derived.”
bone marrow
B cells are produced and mature where?
in red bone marrow
What is the function of B cells?
Responsible for antibody production
Plasma cells are what?
activated B cells/B cells in circulation
Natural killer cells function
- Recognize variety of pathogens
- Attack infected cells & some cancers
- Fast acting
Natural killer cells have what kind of immunity?
innate immunity
What is the first line of defense of the innate immunity system?
Mechanical and chemical barriers
What are the mechanical barriers?
Epidermis and mucosal membranes located where an opening to your body is)
What are the chemical barriers?
Body secretions
Examples: perspiration, saliva, gastric juice
What are the second defense elements of the innate immunity system?
- Phagocytes
- Natural killer cells
- Interferons
- Complement system
What are the phagocytes?
neutrophils, eosinophils, and macrophages/monocytes
- think guard dog
What is the function of phagocytes?
Eat cells or other particulate material
What are the four steps of phagocytosis?
- Chemotaxis
- Adherence
- Ingestion (eat)
- Digestion and killing
What is chemotaxis?
f: moving/following chemical trails = ameboid movement
Natural killer cells function
- Target abnormal cells
- Immunological surveillance
- think guard dog
What are two types of natural killer cells?
Perforins and Granzymes
Perforins function
pokes holes in cell membrane causing cytolysis
What is cytolysis?
breaking up of cell/content spills out
Granzymes function
trigger apoptosis of cells infected by viruses
Interferons belong to what group of cells?
Cytokines (messenger molecules)
Interferons function
- Interferons released by infected cell
- Trigger production of antiviral proteins in neighbors
- Stimulate NK cell and macrophage activity
-think alarm system
What is the Complement system?
- Over 30 proteins
- Always present (in body fluid)
- Set off a series of reactions
- Can work with antibodies
- think booby traps
What is the second line of defense of the innate immunity system?
inflammation
Inflammation is what kind of reaction?
a non-specific defensive reaction/response to cellular/tissue damage
What are the symptoms of inflammation?
redness, swelling, pain, heat
Inflammation function
Isolates injured area
- Clean-up
- Repairs
Response is the same regardless of type of damage
What are the Stages of Inflammation?
First stage: Vasodilation and increased capillary permeability
Second stage: emigration of phagocytes (leukocytes/neutrophils)
Third stage: Tissue repair
The first stage of inflammation causes what ?
Causes an increased blood flow to area (redness)
Causes an increase in plasma moving into tissue
- swelling
Swelling does what?
Increases number of antimicrobial and complement proteins in area
The first stage of inflammation is caused by what?
- histamines (causes vasodilation),
- heparin,
- prostaglandins (intensifies pain)
leukotrienes
What are the cells that cause the first stage of inflammation?
Released by damaged cells, mast cells, basophils
What causes pain in the first stage of inflammation?
- Injury of nerves
- Irritation of microbial products (possible bacteria that got in injury)
- Pressure due to swelling
- Presence of prostaglandins
Second stage: emigration of phagocytes
- Attracted by chemotaxis
- Neutrophils are usually first to arrive
- Monocytes follow later
- Collection of dead neutrophils and monocytes form pus
Third stage: tissue repair
Formation of scar tissue by fibroblasts
What bodily response sometimes accompanies inflammation?
fever
What is the purpose of a fever?
Resetting of hypothalamic thermostat
What hormone substance causes a fever?
Pyrogens (chemical causes an elevation in body temp)
What are the effects of the elevated body temps brought on by a fever?
Intensifies action of interferons (alarm system)
Speeds up repairs (chemical reactions)
What is Adaptive (specific) Immunity?
Ability of the body to defend itself against a specific foreign invader
Adaptive (specific) Immunity function
Specificity (creates specific cells that attack specific pathogens/diseases/viruses)
Adaptive immunity requires what?
exposure to antigen
What are the adaptive immune responses?
Cell-mediated immunity
Antibody-mediated immunity
Cell- mediated immunity
Cytotoxic T cells (killing infected cells)
Antibody-mediated immunity
B cells (produce antibodies)
What cell coordinated the immune responses of cytotoxic cell and B cells?
Helper T cells (gives orders)
Cytotoxic cell and B cells have the ability to do what?
make clones and memory cells
Clones
clones are made of immune specific cells to prevent starting from scratch
Memory Cells
some clones stay behind and hold memories of needed immune response
Who are the key players in adaptive immunity?
Major Histocompatibility Complexes (MHC)
What are Major Histocompatibility Complexes (MHC)?
Glycoproteins in cell membranes
What is the overall function of Major Histocompatibility Complexes (MHC)?
Aid in antigen recognition & T cell activation
What are the two types of Major Histocompatibility Complexes (MHC)?
MHC I and MHC II
MHC I occurs on what kind of cells?
Occur on all nucleated cells
MHC I does not occurs on what kind of cells?
RBCs (because it is non-nucleated)
What is the function of MHC I?
Signal that cell is “normal” or “abnormal”
How are MHC I formed?
Random peptides from cytosol are incorporated into MCH I
if normal peptides are present in MHC I what happens?
T cells ignore it recognizing it as “self”
if abnormal peptides are present in MHC I what happens?
T cell activates and abnormal/infected cell is destroyed
MHC II occurs on what kind of cells?
Only on antigen presenting cells (APCs)
- Phagocytes, lymphocytes, dendritic cells
How are MHC II formed?
Antigens engulfed by phagocytosis are broken down and incorporated into MCH II aka
- Antigen processing
What happens if a foreign antigen/MHC II complex is present?
can lead to activation of
T cells
Helper T cells function
Stimulate both T and B cells
Secrete cytokines
Coordinate activities of immune system
Helper T cells possess what?
Possess CD4 cell markers
Helper t cells respond to what?
Respond to MHC II/antigen complexes
Cytotoxic T function
Attack antigens physically and chemically
How do Cytotoxic T cells attack antigens?
through Lymphotoxin, perforins and apoptosis
Cytotoxic T cells possess what?
Possess CD8 cell markers
Cytotoxic T cells respond to what?
Respond to MHCI/antigen complexes
Memory T
Both cytotoxic and helper T cells
Respond to same antigen on subsequent exposures
Why are there millions of types of B cells?
each holds different antibodies in membrane
B cells contain what?
Also have MHC II
Antigen presenting cells (APC)
Once activated B cells become what?
plasma cells responsible for antibody production
What are the actions of antibodies?
Neutralization
Precipitation and agglutination
Activation of complement system
Attraction of phagocytes
Opsonization
Stimulation of inflammation
Prevention of adhesion
What are the functions of the lymphatic and immune systems?
- Draining excess interstitial fluid
- Transporting dietary lipids and lipid soluble vitamins (A,
D, E, K) to blood - Facilitating the immune response
Where does the lymphatic system take excess interstitial fluid?
Returns it to cardiovascular system
How does the lymphatic and immune systems facilitate immune response?
through:
* Pathogens
- Produce, maintain, and distribute lymphocytes
What are the parts of the lymphatic system?
- lymph
- lymphatic capillaries
- lymphatic vessels
- lymph nodes
- lymph trunks and ducts
Lymph
- Fluid
- Same composition as interstitial fluid
- Only difference is location
- Formed by capillary filtration
Lymph nodes shape
Small, bean shaped structures
* Approximately 600
Lymph nodes location
- Scattered throughout body, but concentrations in neck, groin, and arm pit areas
Lymph nodes contain what?
- Contain macrophages, lymphocytes
Lymph nodes function
filter lymph
