LYMPHATIC SYSTEM Flashcards
the body’s ability to defend and protect itself from damage and pathogens
IMMUNITY
microbes (bacteria and viruses) that have the potential to produce disease
PATHOGENS
non-specific, present at birth
Innate Immunity
specific response to a specific microbe, made up of T cells and B cells
Adaptive Immunity
2 TYPES OF IMMUNITY
- Innate Immunity
2. Adaptive Immunity
specialized form of reticular connective tissue that contains large numbers of lymphocytes
Lymphatic Tissue
TRUE OR FALSE
Interstitial fluid has LESS protein than blood plasma
TRUE
Interstitial fluid has LESS protein than blood plasma
TRUE OR FALSE
Interstitial fluid goes into LYMPHATIC VESSEL to produce lymph
TRUE
Interstitial fluid goes into LYMPHATIC VESSEL to produce lymph
3 PRIMARY FUNCTIONS OF LS
- Drains excess interstitial fluid (edema, excess fluid)
- Transports dietary lipids [transports vit. ADEK (lipid soluble)]
- Carries out immune responses (eliminate pathogens)
enlarges when you have sore throat (back of throat)
Palatine Tonsil
drains lymph on the upper right side of the body
Right lymphatic duct
superior to the heart, midline, turns into fatty tissue after puberty
Thymus
main duct that drains lymph from the rest of the body
Thoracic duct
similar in structure to the veins
Lymphatic vessels
closed at one end and located in spaces bet. cells
Cells overlap
Form lymphatic vessels
Lymphatic capillaries
– similar in structure to veins
Contains lymph nodes
Drains into the right lymphatic duct or thoracic duct
Lymphatic vessels
contains T cells and B cells
Filters lymph
Lymph nodes
receives lymph from the left side of the head, neck, and chest; the left upper limb; and the entire body below the ribs.
THORACIC DUCT
When inhaling, pushes lymph going up to the right and thoracic duct
RESPIRATORY PUMP
Pumps lymph back the general circulation of the body.
SKELETAL MUSCLE PUMP
sites wherein stem cells differentiate into T and B cells
Red Bone Marrow
Thymus
PRIMARY LYMPHATIC ORGANS
sites where most immune responses occur
Lymph nodes
Spleen
Lymphatic nodes
SECONDARY LYMPHATIC ORGANS
: 2 lobed; posterior to sternum, medial to lungs, superior to heart
: Primary lymphoid organ for maturation of T cells
: T cells, dendritic cells, epithelial cells, macrophages
THYMUS
: 600 bean shaped nodes located along lymphatic vessels
: Mammary glands, axillae, groin
: Trap particles in reticular fibers
: Macrophages and lymphocytes
: Lymph nodes enlarge in patients with TB, cancer, etc.
LYMPH NODES
: Largest single mass of lymphatic tissue
: Between the stomach and diaphragm; covered by a capsule of dense connective tissue
SPLEEN
lymphatic tissue, consisting mostly of lymphocytes and macrophages
WHITE PULP
blood-filled venous sinuses consisting of red blood cells, macrophages, lymphocytes, plasma cells, and granular leukocytes
a. Removal by macrophages of worn-out or defective blood cells and platelets
b. Storage of platelets, perhaps up to one-third of the body’s supply
c. Production of blood cells (hemopoeisis) during fetal life.
RED PULP
: Egg-shaped masses of lymphoid tissue
: Gastrointestinal, urinary, repro traits, respi airway
: Tonsils in the pharyngeal region and aggregated lymphatic follicles (Peyer’s patches) in the ileum of the small intestine
LYMPHATIC NODULES
5 Tonsils:
Pharyngeal tonsil or adenoid
2 Palatine tonsils
2 lingual tonsils
2 defenses of the innate immunity
- First line of defense
2. Second line of defense
Enumerate the 10 first line of defenses
- Epidermis
- Mucous membranes
- Mucus
- Hair
- Cilia
- Lacrimal apparatus
- Saliva
8 Urine - Defecation and vomiting
- Chemical barrier
Enumerate the 5 second line of defenses
- Internal antimicrobial substances
- Phagocytes
- Natural killer cells
- Inflammation
- Fever
Enumerate the 4 antimicrobial substances
a. Interferons
b. Complement System
c. Iron-binding proteins
d. Antimicrobial proteins
: From lymphocytes, macrophages and fibroblasts
: Interferes with viral replication
Interferons
: Normally inactive proteins in blood plasma and on plasma membranes
: Stimulates cytolysis, chemotaxis and opsonisation
Complement System
: Reduces amount of available iron
: Transferrin, lactoferrin, ferritin, hemoglobin
Iron-binding proteins
: Short peptides that have broad spectrum of antimicrobial activity
: Dermicidin, defisins and cathelicidins, and thrombocidin
Antimicrobial proteins
Specialized cells that perform phagocytosis (ingestion of microbes or other particle such as cellular debris
PHAGOCYTES
migrate to infected areas
Wandering macrophages
: 5-10% of lymphocytes in the blood
: Have the ability to kill a wide variety of microbes and certain certain tumor cells
: Cellular destruction by releasing proteins that destroy the target cell’s membrane
NATURAL KILLER CELLS
Non-specific defensive response of the body to tissue damage
INFLAMMATION
5 signs and symptoms of inflammation
Redness Pain Heat Swelling Loss of function (sometimes)
collection of dead cells and fluids
PUS FORMATION
a. Abnormally high body temperature (36.5 – 37.4)
b. Occurs during infection and inflammation
c. Interleukin 1 from macrophages – fever causing substances
d. Intensifies the effects of interferons, inhibits the growth of some microbes, and speeds up body reactions that aid repair
FEVER
Forms physical barrier to entrance of microbes
Epidermis of Skin
Inhibit entrance of many microbes, but not as effective as intact skin
Mucous Membrane
Traps microbes in respiratory and gastrointestinal tracts
Mucus
Filter out microbes and dust in nose
Hairs
Together with mucus, trap and remove microbes and dust from upper respiratory tract
Cilia
Tears dilute and wash away irritating substances and microbes
Lacrimal Apparatus
Washes microbes from surfaces of teeth and mucous membranes of mouth
Saliva
Washes microbes from urethra
Urine
Expel microbes from body
Defecation and Vomiting
Forms protective acidic film over skin surface that inhibits growth of many microbes
Sebum
Antimicrobial substance in perspiration, tears, saliva, nasal secretions, and tissue fluids
Lysozyme
Destroys bacteria and most toxins in stomach
Gastric Juice
Protect uninfected host cells from viral infection
Interferons (IFNs)
Causes cytolysis of microbes; promotes phagocytosis; contributes to inflammation
Complement System
Inhibit growth of certain bacteria by reducing amount of available iron
Iron-binding proteins
Have broad-spectrum antimicrobial activities and attract dendritic cells and mast cells
Antimicrobial proteins (AMPs)
Kill infected target cells by releasing granules that contain perforin and granzymes; phagocytes then kill released microbes
Natural Killer (NK) cells
Ingest foreign particulate matter
Phagocytes
Confines and destroys microbes; initiates tissue repair
Inflammation
Intensifies effects of interferons; inhibits growth of some microbes; speeds up body reactions that aid repair
Fever
Specific types of cells or specific antibodies that destroy a particular antigen
ADAPTIVE IMMUNITY
any substance, such as microbes, foods, drugs, pollen, or tissue that immune system recognizes as foreign
ANTIGEN
branch of science that deals with the responses of the body to antigens
IMMUNOLOGY
cells and tissues that carry out immune responses
IMMUNE SYSTEM
lack of reaction against self-tissues
SELF-TOLERANCE
Both develop in primary lymphatic organs (red bone marrow and the thymus) from stem cells that originate in red bone marrow
B CELLS AND T CELLS
cytotoxic T cells directly attack invading antigens
Humoral immunity
Cells attacking cells
Intracellular pathogens
Cell-mediated immunity
B cells transform into plasma cells
Antibody mediated immunity
process by which a lymphocyte proliferates and differentiates in response to a specific antigen
CLONAL SELECTION
destruction or invasion of the antigen
Active helper T cells
Active cytotoxic T cells
Plasma cells
EFFECTOR CELLS
do not actively participate in the initial immune response
Memory helper T cells
Memory cytotoxic T cells
Memory B cells
MEMORY CELLS
causes the body to produce specific antibodies and/ or specific T cells that react with it.
ANTIGEN
self – antigens located at the plasma membrane surface of most body cells
MAJOR HISTOCOMPATIBILITY COMPLEX
Enumerate the 5 classes of immunoglobulins.
- IgG
- IgA
- IgM
- IgD
- IgE
MAJORITY OF ALL ANTIBODIES
About 80% of all antibodies in the blood; also found in lymph and intestines
Protects against bacteria and viruses by enhancing phagocytosis, neutralizing toxins, and triggering the complement system
Only class of antibody to cross the placenta from mother to fetus, conferring considerable immune protection in newborns
IgG
SECRETED IN BREAST MILK; INFERS IMMUNITY TO THE BABY
About 10-15% of all antibodies in the blood; found in sweat, tears, saliva, mucus, breast milk, and gastrointestinal secretions
Levels decrease during stress, lowering resistance to infection
Provides localized protection against bacteria and viruses on mucous membranes.
IgA
About 5-10% of all antibodies in the blood; found in lymph
First antibody class to be secreted by plasma cells after an initial exposure to any antigen
Activates complement and causes agglutination and lysis of microbes
In blood plasma, anti-A and anti-B antibodies of ABO blood group, which bind to A and B antigens during incompatible blood transfusions, are also IgM antbodies
IgM
About 0.2% of all antibodies in the blood; found in lymph and on the surfaces of B cells as antigen
Involved in activation of B cells
IgD
Less than 0.1% of all antibodies in the blood; located o mast cells and basophils
Involved in allergic and hypersensitivity reactions and provides protection against parasitic worms
IgE
recognize antigen in lymph, interstitial fluids or blood plasma
B cells
can only recognize fragments of antigen if presented a certain way
T cells
antigenic proteins are broken down into fragments and then combine with MHC molecules.
Antigen processing
the antigen – MHC complex is inserted into the plasma membrane of a body cell
Antigen presentation
process and present antigens
Antigen presenting cells
6 Steps of processing and presenting antigens
- Ingestion of the antigen
- Digestion of antigen into fragments
- Synthesizes of MHC molecules
- Fusion of vesicles
- Binding of fragments to MHC molecules
- Insertion of antigen - MHC complexes into the plasma membrane
Antigen-presenting cell ingest antigens by phagocytosis. Ingestion could occur almost anywhere in the body that invader, such as microbes have penetrated the non-specific defenses.
Ingestion of the antigen
Within the APC, protein-digesting enzymes split large antigens into short peptide fragments.
Digestion of antigen into fragments
At the same time, the APC synthesizes MHC molecules and packages them into vesicles.
Synthesizes of MHC molecules
The vesicles containing antigen fragments and MHC molecules merge and fuse.
Fusion of vesicles
After fusion of the two vesicles, antigen fragments bind to MHC molecules.
Binding of fragments to MHC molecules
◊ The combined vesicle that contains antigen
◊ MHC complexes splits open and the antigen
◊ MHC complexes are inserted into the plasma membrane
Insertion of antigen – MHC complexes into the plasma membrane
Steps in T cell and cell mediated immunity
- Activation
- Clonal Selection
- Clone cells (effector and memory cells)
- Elimination
2 types of mature T cells
- Helper T cells
2. cytotoxic T cells
activation = clone of active helper T cells and memory helper T cells
Helper T cells
help other cells of the adaptive immune system combat intruders; releases IL-2
Active helper T cells
not active cells. If same antigen enters the body again, it can quickly proliferate and differentiate into more active helper T cells and more memory helper cells.
Memory helper T cells
activation = clone of active cytotoxic T cells and memory cytotoxic T cells
Cytotoxic T cells
attack other body cells that have been infected with the antigen
Active cytotoxic T cells
can quickly proliferate ad differentiate into more active cytotoxic T cells and more memory cytotoxic cells
Memory cytotoxic T cells
: Recognize and attach to target cells to kill them
: Similar to NK but have specific receptors for specific microbes
Cytotoxic T cells
2 mechanisms for killing infected target cells
- Phagocytosis
2. Binding to infected cells and releasing perforin
protein-digesting enzymes that trigger apoptosis.
Granzymes
forms holes/ leakage
Granulysin
targets DNA of cells
Lymphotoxin
interferon (attracts and activates phagocytic cells and macrophage migration inhibition)
Gamma
Steps in B cells and antibody-mediated immunity
- Activation
- Clonal Selection
- Effector and Memory Cells
second stimulating signal
Costimulation
common costimulator
interleukin-2 (IL-2)
FUNCTIONS OF ANTIBODIES (5)
- Neutralize antigen
- Immobilize bacteria
- Agglutinate antigen (clumping together of particles)
- Activate complement proteins (remove microbes through opsonisation and cytolysis)
- Enhance phagocytosis
Processes and presents foreign antigens to T cells; include macrophages, B cells, and dendritic cells
Antigen-presenting Cell (APC)
Helps other cells of immune system combat intruders by releasing costimulator protein interleukin-2 (IL-2), which enhances activation and division of T cells; other proteins attract phagocytes and enhance phagocytic ability of macrophages; also stimulates development of B cells into anti-body producing plasma cells and development of natural killer cells
Helper T Cell
Kills host target cells by releasing granzyms that induce apoptosis, perforin that forms channels to cause cytolysis, granulysin that destroys microbes, lympotoxin that destroys target cell DNA, gamma-interferon that attracts macrophages and increases their phagocytic activity, and macrophage inhibition factor that prevents macrophage migration from site of infection
Cytotoxic T Cell
Remains in lymphatic tissue and recognizes original invading antigen, even years after the first encounter
Memory T Cell
Differentiates into antibody-producing plasma cell
B Cell
Descendant of B cell that produces and secretes antibodies
Plasma Cell
Remains ready to produce a more rapid and forceful secondary response if the same antigen enter the body in the future
Memory B Cell
: Memory for specific antigens that have triggered immune responses in the past
: Due to the presence of long-lasting antibodies and very long-lived lymphocytes that arise during division and differentiation of antigen-stimulated B cells and T cells.
IMMUNOLOGICAL MEMORY
Response is quicker and more intense during subsequent exposure
PRIMARY AND SECONDARY RESPONSES
Process of primary response (4)
- Initial contact
- No antibodies for a few days
- Levels of antibodies slowly rise (IgM, IgG)
- Gradual decline
: Accelerated, more intense
: Every new encounter w/ the same antigen causes a rapid division of memory cells
: The antibody level after subsequent encounters is far greater than during a primary response and consists mainly of IgG antibodies
SECONDARY RESPONSE
Process of the effects of vaccines
- Vaccines
- Inactivated or live microbes
- Activation of B and T cells
- Secondary response on subsequent encounter
Type of adaptive immunity where:
Following exposure to a microbe, antigen recognition by B cells and T cells and costimulation lead to antibody-secreting plasma cells, cytotoxic cells, and B and T memory cells
Naturally Acquired Active Immunity
Type of adaptive immunity where:
Transfer of IgG antibodies from mother to fetus across the placenta, or of IgA antibodies from mother to baby in milk during breast-feeding.
Naturally Acquired Passive Immunity
Type of adaptive immunity where:
Antigens introduced during a vaccination stimulate cell-mediated and antibody-mediated immune responses, leading to production of memory cells. The antigens are pre-treated to be immunogenic but not pathogenic; that is, they will trigger an immune response but not cause significant illness
Artificially Acquired Active Immunity
Type of adaptive immunity where:
Intravenous injection of immunoglobulins (antibodies)
Artificially Acquired Passive Immunity
This causes increased infections and malignancies.
ADVANCING AGE
Effects of aging in the immune system (3):
- Response to vaccines is decreased
- Produce more autoantibodies (antibodies against their body’s own molecules)
- The immune system exhibits lowered levels of function
Lymphatic vessels drain excess interstitial fluid and leaked plasma proteins from dermis of skin
Immune system cells (intraepidermal macrophages) in skin help protect skin
Lymphatic tissue provides IgA antibodies in sweat
INTEGUMENTARY SYSTEM
Lymphatic vessels drain excess interstitial fluid and leaked plasma proteins from connective tissue around bones
SKELETAL SYSTEM
Lymphatic vessels drain excess interstitial fluid and leaked plasma proteins from muscles
MUSCULAR SYSTEM
Immune cells help protect the nervous system from pathogens and the brain helps regulate immune responses
Lymphatic vessels drain excess interstitial fluids and leaked proteins from the nervous system
Neuropeptides function as neurotransmitters
NERVOUS SYSTEM
Flow of lymph helps distribute some hormones and cytokines
Lymphatic vessels drain excess interstitial fluid and leaked plasma proteins from endocrine glands
ENDOCRINE SYSTEM
Lymph returns excess fluid filtered from blood capillaries and leaked plasma proteins to venous blood
Macrophages in spleen destroy aged red blood cells and remove debris in blood
CARDIOVASCULAR SYSTEM
Tonsils, alveolar macrophages, and MALT (mucosa-associated lymphatic tissue) help protect lungs from pathogens
Lymphatic vessels drain excess interstitial fluid from lungs
RESPIRATORY SYSTEM
Tonsils and MALT help defend against toxins and pathogens that penetrate the body from the gastrointestinal tract
Digestive system provides IgA antibodies in saliva and gastrointestinal secretions
Lymphatic vessels pick up absorbed dietary lipids and fat-soluble vitamins from the small intestine and transport them to the blood
Lymphatic vessels drain excess interstitial fluids and leaked plasma proteins from organs of the digestive system
DIGESTIVE SYSTEM
Lymphatic vessels drain excess interstitial fluid and leaked plasma proteins from organs of the urinary system
MALT helps defens against toxins and pathogens that penetrate the body via the urethra
URINARY SYSTEM
Lymphatic vessels drain excess interstitial fluid and leaked plasma proteins from organs of the reproductive system
MALT helps defend against toxins and pathogens that penetrate the body via the vagina and penis
In females, sperm deposited in the vagina are not attacked as foreign invaders use to inhibition of immune responses
IgG antibodies can cross the placenta to provide protection to a developing fetus
Lymphatic tissue provides IgA antibodies in the milk of a nursing mother
REPRODUCTIVE SYSTEMS