LYMPHATIC Flashcards
lymph, lymphocytes, lymphatic vessels, lymph nodes, tonsils, spleen, thymus
- does not circulate fluid to and from tissues
- carries fluid in one direction, from tissues to circulatory system
- most fluid returns to blood, some move into lymphatic capillaries to become lymph
lymphatic system
tiny, close-ended vessels consisting of simple squamous epithelium
- more permeable than blood capillaries because they lack a basement membrane
- its overlapping squamous cells act as valves (prevent backflow of fluid)
- present in most tissues except CNS, bone marrow, tissues without blood vessels (epidermis & cartilage)
- join to form lymphatic vessels
lymphatic capillaries
resemble small veins
- small LV have beaded appearance because they have one-way valves
- when compressed, valves prevent backward movement, causing lymph to move forward
- converge and empty into the blood at two locations:
lymphatic vessels
– tonsils, lymph nodes, spleen, thymus
LYMPHATIC ORGANS
– lymphocytes and other cells
LYMPHATIC TISSUE
form a protective ring of lymphatic tissue around the openings between the nasal and oral cavities and pharynx
-protect against pathogens and other potentially harmful material entering from the nose and mouth
tonsils
form interlaced network that holds the lymphocytes and other cells in place
-traps microorganisms and other items in the fluid when lymph or blood filters through lymphatic organs
reticular fiber
iginate from red bone marrow and are carried by blood to lymphatic organs
-divide and increase in number when the body is exposed to microorganisms or foreign substances
lymphocytes
posterior opening of the oral cavity, “the tonsils”
PALATINE
– near the internal opening, called adenoids when enlarged
PHARYNGEAL
posterior surface of the tongue
- Lingual
rounded structures
- distributed along various lymphatic vessels
- where lymph passes before entering the blood
LYMPH NODES
3 Superficial Aggregations of Lymph Nodes on each side of the body
- Inguinal nodes – groin
- Axillary nodes – axilla
- Cervical nodes – neck
– dense CT surrounding each node
CAPSULE
subdivide a lymph node into compartments containing lymphatic tissue and sinuses
Trabeculae
dense aggregations of tissue
LYMPH ATIC NODULES
spaces between lymphatic tissue containing macrophages
LYMPH ATIC sinuses
– lymphatic nodules containing rapidly dividing lymphocytes
germinal; centers
– clenched fist, left, superior corner of the abdominal cavity
- outer capsule of dense CT and some smooth muscle
- divided into compartments by trabeculae
- filters blood instead of lymph
- detect and respond to foreign substances in the blood & destroy worn-out rbc
- blood reservoir (used in emergency situations, little blood only)
spleen
part of spleen
lymphatic tissue surrounding arteries within the spleen
white pulp
– associated with veins
-a fibrous network filled with macrophages and RBC, enlarged capillaries connecting to veins
red pulp
- bilobed gland, triangular in shape
- in superior mediastinum
- each lobe surrounded by capsule
- divided into lobules by trabeculae
- site for maturation of T cells
thymus
– near the capsule and trabeculae
-dark-staining areas formed by numerous lymphocytes
cortex
– lighter-staining central portion with fewer lymphocytes
medulla
-ability to resist damage from foreign substances, harmful chemicals and internal threats
IMMUNITY
body recognizes and destroys certain foreign substances
-response is same each time the body is exposed
INNATE IMMUNITY
– body recognizes and destroys foreign substances
-response improves each time the foreign substance is encountered
ADAPTIVE IMMUNITY
ability of adaptive immunity to recognize a particular substance
SPECIFICITY
ability of adaptive immunity to remember previous encounters with a particular substances
MEMORY
INNATE IMMUNITY WHICH prevent microorganisms and chemicals from entering the body in 2 ways:
PHYSICAL BARRIERS
HOW PHYSICAL BARRIERS prevent microorganisms and chemicals from entering the body
- Skin and mucous membrane form barriers
2. Tears, saliva, and urine was substances
-molecules responsible for many aspects of innate immunity
CHEMICAL MEDIATORS
– group of approximately 20 proteins found in plasma
- normally, they circulate in blood in an inactive form
- activated by combining with foreign substances, such as parts of a bacterial cells
- activated by combining with antibodies
- once activation begins, a series of reactions results, in which complement protein activates the next
- once activated, certain complement proteins promote inflammation and phagocytosis and can directly lyse bacterial cells
COMPLEMENT
proteins that protect the body against viral infections
- produced when virus stimulate infected cells to produce interferons
- do not protect the cell that produces them
- bind to surface of neighboring cells, and stimulate them to produce antiviral proteins
- antiviral proteins prevent production of new viral nucleic acids and proteins
- some play a role in activating immune cells
INTERFERONS
most important cellular components of immunity
- produced in red bone marrow & lymphatic tissue
- released into the blood
- attracted by chemicals released from microorganisms or damaged tissues (complement, leukotrienes, kinins, histamine)
WBC
movement of WBC towards those chemicals
CHEMOTAXIS
ingestion & destruction of particles by cells called phagocytES
phagocytosis
small phagocytic cells
- first cells to enter infected tissues from blood in large numbers
- release chemical signals that increase inflammatory response by recruiting and activating other immune cells
- often die after phagocytizing single microorganism
neutrophil
monocytes that leave the blood, enter tissues, enlarge about fivefold
- dust cells (lungs), Kupffer cells (liver), microglia (CNS), Langerhan cells (skin)
- can ingest more and large items than neutrophils
- responsible for most of the phagocytic activity in late stages of infection
- cleans up dead neutrophils and other debris
- found in uninfected tissues to phagocytize mircroorganisms before they can replicate or cause damage; located at potential points
macrophage
monocytes and macrophages
-phagocytes with a single, unlobed nucleus
MONONUCLEAR PHAGOCYTIC SYSTEM
derived from red bone marrow
-motile, WBC that can leave the blood and enter infected tissues
basophil
derived from red bone marrow
- non-motile cells in CT, near capillaries
- like macrophages, located at potential points
mast cells
- participate in inflammation associated with allergies and asthma
EOSINOPHILS –
type of lymphocyte produced in red bone marrow
- account for up to 15% of lymphocytes
- recognize classes of cells (tumor or virus-infected cells)
NATURAL KILLER (NK) CELLS
- process of releasing chemical mediators and attracting phagocytes and other WBC
- continues until bacteria are destroyed
INFLAMMATORY RESPONSE
inflammatory response confined to specific area of the body
LOCAL INFLAMMATION
inflammatory response generally distributed throughout the body
-also show the 5 cardinal signs of inflammation plus the ff:
SYSTEMIC INFLAMMATION
substances that stimulate adaptive immune responses
ANTIGENS
2 GROUPS OF ANTIGENS
FOREIGN
SELF-ANTIGEN
ANTIGENS introduced from outside the body
-Ex: microorganisms
FOREIGN
– overreaction of the immune system
ALLERGIC RXN
– molecules the body produces to stimulate an immune system response
-response can be beneficial or harmful
SELF-ANTIGEN
– self-antigens stimulate unwanted destruction of normal tissue
AUTOIMMUNE DISEASE
2 Types of Adaptive Immunity
ANTIBODY-MEDIATED
CELL-MEDIATED
lymphocytes
produced in the blood, and trained in thymus
T cells
lymphocytes
trained in bone marrow
B cells
*There are___ T cells for every ____ B cell.
5:1
small groups of identical B cells or T cells, formed during embryonic development
- derived from a single unique T cell or B cell
- each can respond to only a particular antigen
- response to self-antigen is suppressed because it could destroy the body’s own cells
- have identical antigen receptors
clones
For the adaptive response of B cells or T cells to be effective, the following must occur
- Antigen recognition by lymphocytes
2. Proliferation of lymphocytes recognizing the antigen
– proteins of lymphocytes on their surface (B-cell receptors and T-cell receptors)
-binds only to a specific antigen
ANTIGEN RECEPTORS
glycoproteins that have binding sites for antigens
-serving trays that hold and present a processed antigen
MAJOR HISTOCOMPATIBILITY COMPLEX(MHC) MOLECULES
MHC on membranes of most nucleated cells
• MHC CLASS I –
MHC on membranes of antigen-presenting cells, B cells, lymphocytes
MHC CLASSII
necessary to aid first signal in producing a response
-can be achieved by CYTOKINES
COSTIMULATION
cytokine released by macrophages that can stimulate helper T cells
INTERLEUKIN - 1
glycoproteins of helper T Cells
- help connect helper T cells to macrophage by binding to MHC Class II molecules
- also bound by virus that causes AIDS
CD4
– glycoproteins of cytotoxic T cells
-helps connect cytotoxic T cells to cells displaying MHC Class I molecules
CD8
TYPE OF IMMUNITY -effective against extracellular antigens because antibodies are in body fluids
ANTIBODY MEDIATED
proteins produced in response to an antigen
-Y-shaped molecules consisting of 4 polypeptide chains: 2 identical heavy chains & 2 identical light chains
ANTIBODIES
-are sometimes called gamma globulins because they are mostly found in gamma globulin part of plasma
ANTIBODIES
-are sometimes called immunoglobulins because they globulins involved in immunity
ANTIBODIES
PART OF ANTIBODY
– end of each arm of the antibody
-part that combines with antigen
-join only with a particular antigen
VARIABLE REGION
PART OF ANTIBODY
rest of the antibody
-has several functions
CONSYTANT REGION
EFFECT OF ANTIBODIES
occur when a single antibody binds to an antigen and inactivates the antigen
-or when many antigens are bound together and are inactivated by many antibodies
DIRECT
EFFECT OF ANTIBODIES
– constant region of the antibody activates other mechanisms that destroy antigen, after antibody has attached to antigen via variable region
INDIREC
TYPE OF RESPONSE
– results from the first exposure of a B cell to an antigen
-3-14 days to produce enough antibodies to be effective against antigen
-in the meantime, disease symptoms develop
PRIMARY RESPONSE
responsible for secondary response
MEMORY B CELLS
occurs when immune system is exposed to an antigen against which it has already produced a primary response
- antigen is quickly destroyed, no disease symptoms, person is immune
- persist for many years
MEMORY RESPONSE
- if they are short-lived, there would be repeated infections of same disease (common colds)
- provides better protection because:
1. time required to start producing antibodies is less
2. more plasma cells and antibodies are produced
MEMORY RESPONSE
TYPE OF IMMUNITY
- function of cytotoxic T cells
- most effective against microorganisms that live inside the body cells (virus and some bacteria)
CELL MEDIATED IMMUNITY
TYPE OF IMMUNITY
- when viruses infect cells, some viral proteins are broken down and become processed antigens combined with MHC Class I
- CT cells can distinguish infected cells because T-cell receptor can bind to MHC class I/viral antigen complex
- T cell receptor and complex signal for activating cytotoxic T cells
CELL MEDIATED IMMUNITY
-responsible for cell-mediated response
2 Main Effects:
1. Release cytokines – activate additional components of immune system
2. CT cells can come in contact with other cells and kill them
CYTOTOXIC T CELLS
TYPE OF ACQUIRED IMMUNITY
results from natural exposure to an antigen that stimulates IS to respond agains antigen
-individual develops symptoms of disease because individual is not immune during 1st exposure
ACTIVE NATURAL
TYPE OF ACQUIRED IMMUNITY
antigen (vaccine) is deliberately introduced into an individual to stimulate the IS (vaccination)
• ACTIVE ARTIFICIAL IMMUNITY
TYPE OF ACQUIRED IMMUNITY
– when antibodies are transferred from a mother to her child across the placenta before birth
PASSIVE NATURAL
TYPE OF ACQUIRED IMMUNITY
vaccinating an animal, animal’s IS acquires
PASSIVE ARTIFICIAL
consists of a part of microorganism (dead or altered)
-antigen has been changed so it will stimulate an immune response but will not call the disease symptoms
VACCINE
