Lymphatic System Flashcards
Define immune system
Defends the body from agents of disease
Functions of lymphatic system
Network of organs and vein like vessels that recover fluid
Inspect it for disease agents
Activate immune response
PROTECT BODY FROM INFECTION AND DISEASE
Return fluid to the bloodstream (MAINTAINS FLUID BALANCE)
What is considered to be a pathogen
Microorganisms
Bacteria, virus, fungus, parasites
Lymph
Recovered colorless fluid
Clear
Similar to plasma but with less plasma
Originates as extra cellular fluid drawn into lymphatic capillaries
Lymphatic tissues
Composed of aggregates of lymphocytes and macrophages that populate many organs in the body
Lymphatic organs
Defense cells are especially concentrated in these organs
Separated from surrounding organs by connective tissue capsules
Lymphatic capillaries
(Terminal lymphatics)
Penetrate nearly every tissue of the body
Absent from central nervous system, cartilage, cornea, bone, and bone marrow
Endothelium creates valve-like flaps that open when interstitial fluid pressure is high and close and when it is low
Lymphatic vessels have a ______ appearance
Beaded
Fluid recovery
Fluid continually filters from the blood capillaries into the tissue spaces
Blood capillaries reabsorb 85%
15% enter the lymphatic system and then are returned to the blood
Immunity
Excess filtered fluid picks up foreign cells and chemicals from the tissues
Passes through lymph nodes where immune cells stand guard against foreign matter
Activates a protective immune response
Lipid absorption
Lacteals in small intestine absorb dietary lipids that are not absorbed by the blood capillaries
Flow of lymph
Lymph flows similar to venous return, except no pump (heart)
Lymph flows at low pressure and slower speed than venous blood
Moved along by rhythmic contractions of lymphatic vessel
Stretching of vessels stimulates contraction
Flow aided by skeletal muscle pump
Arterial pulsation rhythmically squeezes lymphatic vessels
Thoracic pump aids flow from abdominal to thoracic cavity
Valves prevent backward flow
What are the primary lymphatic organs
Red bone marrow and thymus
What is the site where T and B cells become immunocompetent
Primary lymphatic organs
Red bone marrow
Thymus
Red bone marrow produces
RBCs, WBCs, Plateletsd
Thymus produces
T cells
What are the types of white blood cells
Neutrophils, macrophage, eosinophils, basophils, lymphocyte
What are the types of lymphoctes
B lymphocyte T lymphocytes (MADE IN THE THYMUS)
What are the secondary lymphatic organs
Lymph nodes
Tonsils
Spleen
Parts of the appendix
What tissues do immunocompetent cells populate ?
Lymph nodes
Tonsils
Spleen
Red bone marrow is involved in ___ and ___
Hemopoiesis (blood formation)
And
Immunity
What are the functions of thymus
Houses developing T lymphocytes
Secretes hormones regulating their activity
Found in between sternum and aortic arch
Degeneration with age
Lobes have cortex and medulla populated by
T lymphocytes
Where are lymph nodes found
Cervical
Axiliary
Thoracic
Abdominal
Intestinal
Mesenteric
Inguinal
Popliteal lymph nodes
What are the functions of lymph nodes
Cleanse the lymph
Act as a side of T and B cell activation
PATHOGEN RECEPTORS GET SIGNALS FOR ACTIVATION
WHEN MAKING WBC IN RBM THEY HAVE TO GO THROUGH TESTS BECAUSE IT CANT ALLOW IMMATURE CELLS
Parenchyma divided into
Cortex and medulla
Germinal centers is where
B cells multiply and differentiate into plasma cells
Afferent lymphatic vessels lead into
The node along its convex surface
Lymph leaves the node through 1-3
Efferent lymphatic vessels that leave the hilum
T lymphocytes
T cells
mature in thymus
B lymphocytes
B cells
activation causes proliferation and differentiation into plasma cells that produce antibodies
Natural Killer cells
NK Cells
large lymphocytes that attack and destroy •bacteria
•transplanted tissue
•host cells infected with viruses or have turned cancerous
Dendritic cells
branched, mobile APCs found in epidermis, mucous membrances and lymphatic organs
alert immune system to pathogens that have breaches the body surface
lymphatic (lymphoid) tissue
collection of lymphocytes in the connective tissues of mucous membrances and verious organs
lymphatic nodules (follicles)
dense masses of lymphocytes and macrophages that come together in response to pathogens
- lymph nodes
- nodes
- tonsils
- appendix
Peyer patches
dense clusters in the ileum (the distal part of the small intestine)
neutrophils
kill bacteria in the connective tissue
can kill using phagocytosis and digestion
can kill by making a cloud of bactericidal chemicals
lysosomes degranulate
discharge enzymes into tissue fluid causing a respiratory burst
creates a killing zone around neutrophil destroying several bacteria
macrophages
large, phagocytic cells
come from monocytes
macrophaes phagocytize _
tissue debris
dead neutrophils
bacteria
other foreign matter
what do macrophages do to foreign matter
once its processed, it displays antigenic fragments to certain T cells alerting immune system to the presence of the enemy
macrophages are considered to be _
one of the antigen presenting cells (APC’s)
Lymphadenitis
Swollen, painful node responding to foreign antigen
Lymphadenopathy
Collective term for all lymph node diseases
Metastasis
Cancerous cells break free from original tumor, travel to other sites in the body, and establish new tumors
What is the process of metastasis
Metastasizing cells enter lymphatic vessels
Multiply there and destroy the lymph nodes
Swollen, firm, and usually painless
(LIKE TUBERCULOSIS, IT BECOMES RUBBERY)
Tonsils
Patches of lymphatic tissue located at the entrance to the pharynx
What are the 3 types of tonsils
Palatine tonsils
Lingual tonsils
Pharyngeal tonsil (adenoids)
What are the 2 tonsil related surgery
Tonsillitis (CAN TAKE IT OUT IF IT GETS INFECTED 3X A YEAR FOR 2 CONSECUTIVE YEARS)
Tonsillectomy
Spleen
The body’s largest lymphatic organ
What are the two types of Parenchyma
Red pulp
White pulp
Red pulp
Sinuses filled with erythrocytes (RBC)
White pulp
Lymphocytes
Macrophages (WBC, B LYMPH, T LYMPH)
Both surround small branches of splendid artery
Functions of the spleen
It’s RBC graveyard for old RBCs
White pulp monitors blood for foreign antigens and keeps an army of monocytes for release when needed
True or false:
Spleen is highly vascular and vulnerable to trauma and infection
True
Ruptured spleen requires
Splenectomy
THIS LEAVES PERSON SUSCEPTIBLE TO FUTURE INFECTIONS, AND PREMATURE DEATH
pathogens
Agents capable of producing disease
VIRUSES
BACTERIA
FUNGI
What are the three lines of defenses against pathogens
First line of defense
Second line of defense
Third line of defense
First line of defense/ External defenses
Skin
mucous membranes
Secretions
WORK ON OUTSIDE OF THE CELLS
Second line of defense/ Internal defenses
Several nonspecific defense mechanisms
Phagocytosis cells: Leukocytes, and macrophages
antimicrobial proteins: compliment, and interferon
natural killer cells: cancer cells
inflammatory response: 4 signs; calor, dolor, rubor, tumor
Third line of defense
The immune system
Defeats a pathogen, and leaves the body with a memory of it so it can defeat it faster in the future
Humoral response (antibodies): we have antibodies floating in our bloodstream in plasma B LYMPHOCYTES PRODUCE ANTIBODIES
Cell mediated response (cytotoxic lymphocytes)
Innate immunity/Nonspecific
Rapid responses to a broad range of microbes
Microbes= bacteria, virus, fungus
FIRST AND SECOND LINE DEFENSE
It cant remember which bacteria, fungus, or virus it fought
Acquired immunity/ adaptive/ specific
Third line defense
It can remember; we need to experience infection to develop antibodies
Nonspecific defenses
Guard against a broad range of pathogens
Quick response
• they lack capacity to remember pathogens
What are the 3 types of nonspecific defenses
Protective proteins
Protective cells
Protective processes
Specific/adaptive immunity
Body must develop separate immunity to each specific pathogen
Prevent pathogen from affecting or harming us more easily upon future exposure
External barriers
Skin
Mucous membranes
Skin
Mechanical barrier for microorganisms to enter the body
Toughness of keratin
Acidic ph: thin film of lactic and fatty acids from sweat and sebum(OILY SECRETION) that inhibits bacterial growth
Mucous membranes
Digestive, respiratory, urinary, and reproductive tracts are open to the exterior and protected by mucous membranes
Mucus physically traps microbes
Lysozyme
Enzyme destroys bacterial cell walls
Phagocytes
Cels that engulf foreign matter
Phagocytes cells are
Neutrophils
Macrophages
Dendritic cells
Neutrophils
Killing bacteria by using phagocytosis and digestion
Can kill by producing bactericides chemicals
Macrophages
Phagocytes cells
Monocytes emigrate from the blood into tissues and transform into macrophages
Where are alveolar macrophages
In lungs
Where are kupffer cell
In liver
Langerhans cells
In skin
Where are microglia
In central nervous system
Antimicrobial proteins
Proteins that inhibit microbial reproduction and provide short term, non specific resistance to pathogenic bacteria and viruses
What are the two families of antimicrobial proteins
Interferons
Complement system
Interferons
Secretes by certain cels infected by viruses
Alert neighboring cells and protect them from being infected
Complement system
30 or more globular proteins that make powerful contributions to both nonspecific resistance and adaptive immunity
Synthesized by liver
Circulate in the blood in inactive form
Activated by presence of a pathogen
4 methods of pathogen destruction
Inflammation
Immune clearance
Phagocytosis
Cytolysis
4 cardinal signs of inflammation
Heat: results from hyperemia
Redness: due to hyperemia and extravasated RBC in the tissue
Swelling (edema): due to increased fluid filtration from the capillaries
Pain: from direct injury to the nerves, pressure on the nerves from edema, stimulation of pain receptors by prostaglandins, bacterial toxins, and bradykinin
Pathogens
NONSPECIFIC RESISTANCE
Agents capable of producing disease
Include viruses, bacteria, and fungi
Nonspecific defenses
Guard against a broad range of pathogens
Quick response
(Protective proteins,protective cells,protective processes )
DONT REMEMBER PATHOGENS
Specific or adaptive immunity
Body must develop separate immunity to each specific pathogen
Prevent the pathogen from affecting or harming us more easily upon future exposure
Immune system
Widely distributed cells that recognize foreign substances and act to neutralize or destroy them
Specificity
Immunity directed against a particular pathogen
Memory
When re-exposed to the same pathogen the body reacts so quickly that there is no noticeable illness
True or false:
The adaptive immune system is antigen specific, systemic and has memory
True
What are the two overlapping arms of Adaptive immunity
Humoral immunity
(antibody mediated) (B cell)
Cellular immunity (cell mediated)
Cellular immunity
Lymphocytes directly attack and destroy foreign cells or diseased host cells
Rids the body of pathogens that reside inside human cells, where they are inaccessible to antibodies
Kills cells that harbor them
Humoral immunity
Mediated by antibodies that do no directly destroy a pathogen but tag it for destruction
Antibodies are dissolved in body fluids
Can only work against the extra cellular stages of infections by microorganisms
B lymphocytes
Oversee humoral immunity
T lymphocytes
Non antibody producing cells that constitute the cell mediated arm of immunity
What are the major antigen presenting cells
Dendritic cells
Macrophages
Activated B cells
Functions of antigen presenting cells
Engulf foreign particles
Present fragments of antigens on their own surfaces to be recognized by T cells
They do not response to specific antigens
Macrophages and dendritic cells secrete soluble proteins that activate
T cells
Primary immune response
3-6 days
Peak levels of plasma antibody are achieved in 10 days
Antibody levels then decline
Secondary immune response
Antibody levels peak in 2-3 days
Sensitized memory cells respond within hours
Define immunoglobulin
A defensive gamma globulin found in blood plasma, tissue fluids, body secretions
True or false:
Immunoglobulins are soluble proteins secreted by activated B cells and plasma cells in response to an antigen
True
What are the 5 classes of antibodies
IgD
IgM
IgG
IgA
IgE
IgM
Pentamer
Primary response
Can fight against many pathogens at the same time
IgG
Monomer
Most abundant
Primary and secondary response
Crosses the placenta
2ND EXPOSURE
IgA
Dimer
Prevent attachment of pathogens
Involved in secretions such as tears and breast milk
IgE
Monomer
Binds to mast cells and basophils
Histamine release
Attracts eosinophils to parasitic infections
Produces immediate hypersensitivity reactions
What are the 3 types of T cells mediate cellular immunity
- helper T cells (CD4 CELLS/ T4 CELLS)
- cytotoxic T cells (TC/ CD8 CELLS/ T8 CELLS)
- Memory T cells
Cell mediated immune response helps when
Antibodies cant help against intracellular antigens
What is the importance of cellular response
T cells recognize and respond only to processed fragments of antigen displayed on the surface of body cells
T cells are best suited for cell to cell interactions and target
Cells infected with viruses, bacteria, or intracellular parasites
Abnormal or cancerous cells
Cells of infused or transplanted foreign tissue
T cells must simultaneously recognize
Non self (the antigen)
Self (a MHC protein of a body cell)
Class I MHC proteins
Recognized by CD8 T cells
Present in almost all nucleated cells
Class II MHC proteins
Found only on mature B cells, some T cells, and antigen presenting cells
Recognition by CD4 cells
OUR OWN BODY CELLS
Cytotoxic T cell
The only T cells that can directly attack and kill other cells
What are the cytotoxic T cells targets
Virus infected cells
Cells with intracellular bacteria or parasites
Cancer cells
Foreign cell from blood transfusions or transplants
Helper T cells
Adaptive immune response
Chemically or directly stimulate proliferation of other T cells
Stimulate B cells that have already become bound to antigen
Helper T cells play central role in
Coordinating cellular and humoral immunity
What is the role of helper T cells in attack
Secretes interleukins
Attract neutrophils and NK cells
Attract macrophages, stimulate their phagocytic activity and stop them from leaving the area
Stimulate T and B cell mitosis and maturation
What is the role of cytotoxic cells in attack
Deliver chemicals
Performing and granzymes (THESE KILL CELLS LIKE NK CELLSDO)
Interferons (INHIBIT VIRAL REPLICATION, AND ACTIVATE MACROPHAGES)
Tumor necrosis factor (TNF) (AIDS IN MACROPHAGE ACTIVATION AND KILLS CANCER CELLS)
After this, TC cells go to look for another enemy
True or false:
Cytotoxic T cells are the only T cells that directly attack other cells
True
What does a TC cell do when it recognizes a complex of antigen and MHC I protein on a diseased or foreign cell
It binds/ docks
Natural active immunity
Result of infection or natural exposure to antigen
Artificial active immunity
Production of one’s own antibodies or T cells as a result of vaccination against disease
Natural passive immunity
Fetus acquires antibodies from mother through placenta, or milk
Artificial passive immunity
Injection of immune serum (antibodies) from another person or animal
Hypersensitivity
An excessive immune reaction against antigens that most people tolerate
