Chapter 2 Organization of Lymph/Immune Flashcards
The body system responsible for adaptive immunity
Lymphatic system
Lymphatic system consists of:
Lymph
Lymphatic vessels
Structures and organs containing lymphatic tissue
Red bone marrow
Specialized form of reticular connective tissue that contains large numbers of lymphocytes
Lymphatic tissue
After interstitial fluid passes into lymphatic vessels, it is called:
Lymph
Main difference between interstitial fluid/lymph and plasma
Interstitial fluid and lymph contain less protein
Each day, about __ liters of fluid filter from blood into tissue spaces
20 liters
__ liters of fluid filtered daily from the arterial end of blood capillaries return to the blood directly by reabsorption at the venous end of capillaries
17 liters
Lymphatic system three primary functions
Drains excess interstitial fluid
Transports dietary lipids
Carries out immune responses
Basic flow of lymph
Lymph capillaries
Lymph vessels
Thoracic duct OR right lymphatic duct
Structure of lymphatic vessels compared to veins
Thinner walls and more valves
What is located along lymphatic vessels?
Lymph nodes
Masses of B cells and T cells that are surrounded by a capsule
Lymph nodes
Main lymph-collecting duct, receives lymph from the left side of head, neck, chest, upper limb, and entire body below the ribs
Thoracic duct
Drains lymph from the upper right side of the body
Right lymphatic duct
Thoracic duct empties lymph into:
Junction of the left internal jugular and left subclavian veins
Right lymphatic duct empties its lymph into:
Junction of the right internal jugular and right subclavian veins
Two pumps that aid the flow of lymph
Skeletal muscle pump
Respiratory pump
Where stem cells give rise to mature B cells and immature T cells
Red bone marrow (flat bones and ends of long bones)
T cells mature into function T cells.
Two lobed organ located posterior to the sternum.
Thymus
Primary lymphatic organs
Red bone marrow
Thymus
Secondary lymphatic organs (sites where most immune responses occur)
Lymph nodes
Spleen
Lymphatic nodules
Lymph nodes are heavily concentrated near:
Mammary glands
Axillae
Groin
Lymph nodes contain:
B cells
T cells
Plasma cells
Dendritic cells
Macrophages
Location of the spleen
Between the stomach and diaphragm
Two types of tissues found in the spleen
White pulp (B & T cells carry out immune responses)
Red pulp (Blood sinuses that filter out old blood)
Egg-shaped masses of lymphatic tissue
Lining of the GI, urinary, reproductive, and respiratory tracts
Lymphatic nodules
Innate immunity:
First line of defense.
Barriers from skin and mucous membranes
Innate immunity:
Second line of defense.
Internal defenses
- Antimicrobial substances
- Natural killer cells
- Phagocytes
- Inflammation
- Fever
Adaptive immunity involves:
B and T cells
Two types of adaptive immunity
Cell-mediated
Antibody-mediated
Refers to a wide variety that serve to protect us against an invasion.
We are born with this kind of immunity.
Innate immunity
Specialized cells that perform phagocytosis.
Ingest microbes or other particles.
Phagocytes
5-10% of lymphocytes.
Ability to kill a wide variety of microbes and tumor cells.
Cause the cell death by releasing proteins that destroy the target cells membrane
Natural killer cells
Natural killer cells are found:
Spleen
Nodes
Red bone marrow
Non-specific response of body to tissue damage.
Prevents the spread to other tissues and prepares site for repair.
Inflammation
Belong to a group of plasma proteins called globulins.
Known as immunoglobulins.
Antibodies
Five classes of immunoglobulins (antibodies)
IgG
IgA
IgM
IgD
IgE
Percentage of IgG compared to all antibodies in blood
80%
Percentage of IgA in blood compared to all other antibodies
10-15%
Percentage of IgM compared to other antibodies in blood
5-10%
Percentage of IgD and IgE compared to other antibodies in blood
IgD = 0.2%
IgE = 0.1%
Antibodies:
Protects against bacteria and viruses by enhancing phagocytosis.
Only antibody to cross the placenta from mother to fetus.
IgG
Antibodies:
Found mainly in sweat, tears, saliva, mucus, breast milk, and GI secretions.
Levels decrease during stress.
IgA
Antibodies:
First antibody secreted by plasma cells to any antigen.
This is the antibody that binds to A and B antigens during incompatible blood transfusions.
IgM
Antibodies:
Found on surfaces of B cells.
Primarily involved in B cell activation.
IgD
Antibodies:
Located on mast cells and basophils.
Primarily involved in allergic and hypersensitivity reactions.
Provides protection against parasitic worms.
IgE
Antimicrobial substances:
Various body fluids contain four main types that discourage microbial growth.
- Lymphocytes, macrophages, and fibroblasts infected with viruses produce proteins called interferons (IFNs).
- Proteins in blood plasma & plasma membranes makes of the complement system.
- Iron-binding proteins
- Antimicrobial proteins (AMPs)
What diffuses to other neighboring cells, where they stimulate synthesis of proteins that interfere with viral replication?
Interferons (IFNs)
When activated, what proteins “complement” or enhance certain immune, allergic, and inflammatory reactions?
Proteins in blood plasma and plasma membranes
Short peptides that have a broad spectrum of antimicrobial activity.
Dermicidin (sweat glands)
Defensins & Cathelicidins (neutrophils, macrophages, epithelia)
Thrombocidin (platelets)
Antimicrobial proteins (AMP)
When microbes penetrate the skin and mucous membranes or bypass the antimicrobial substances in blood, the next defense consists of:
Phagocytes
Natural Killer cells
Four signs and symptoms of inflammation:
Redness
Pain
Heat
Swelling
Many bacterial toxins elevate body temperature, sometimes by triggering release of fever-causing substances such as:
Interleukin-1 from macrophages
What does having a fever do?
Intensifies effects of interferons
Inhibits growth of microbes
Speeds up body reactions that aid in repair
Immunity the involves the production of specific types of cells or specific antibodies to destroy a particular antigen
Adaptive (specific)
Branch of science that deals with the responses of the body to antigens
Immunology
Lack of reaction of a person’s adaptive immune against their own tissues and chemicals
Self-tolerance
Adaptive immunity involves lymphocytes called:
B and T cells
Two major types of mature T cells that exit the thymus
Helper T cells
Cytotoxic T cells
Two types of adaptive immunity
Cell-mediated
Antibody-mediated
In cell-mediated immunity, _____ directly attack invading antigens
Cytotoxic T cells
In antibody-mediated immunity, ______ transform into plasma cells, which synthesize and secrete specific proteins called antibodies
B cells
What cells aid the immune responses of both cell-mediated and antibody-mediated immunity?
Helped T cells
Cell-mediated immunity is particularly effective against:
1) Intracellular pathogens
2) Some cancer cells
3) Foreign tissue transplants
Antibody-mediated immunity is also referred to as:
Humoral immunity
Process by which a lymphocyte proliferates (divides) and differentiates (forms more highly specialized cells) in response to a specific antigen
Clonal Selection
Clonal selection of lymphocytes occurs in:
Secondary lymphatic organs and tissues
A lymphocyte that undergoes clonal selection gives rise to what two major types of cells in the close?
Effector cells
Memory cells
What cells eventually die after the immune response has been completed?
Effector cells
What cells do not die at the end of an immune response.
Instead, have long life spans (usually decades)
Memory cells
Antibody generator
Antigen
Located at the plasma membrane surface of most body cells
“self-antigens”
Major histocompatibility complex (MHC) Proteins
The reason tissues may be rejected when they are transplanted from one person to another
Normal function is to help T cells recognize that an antigen is foreign
Major Histocompatibility Complex (MHC) Proteins
Antigens induce ____ cells to secrete proteins known as antibodies
plasma
Most antibodies contain ___ polypeptide chains
four
In a sick patient, a high level of ___ against a particular pathogen helps identify the cause of illness
IgM
Resistance of the fetus and newborn to infection stems from:
IgG (placenta)
IgA (breast milk)
When would T cells ignore an antigen-MHC complex?
If the fragment comes from a self-protein
Antigen-MHC complex is inserted into the plasma membrane of a body cell
Antigen presentation