What 3 things is the Lymphatic System responsible for?
Fluid balance, absorption of fats, and Immunological defense.
What is the function of the Lymphatic capillaries?
To transport Lymph from interstitial space to the blood.
What is the major difference between blood capillaries and lymphatic capillaries?
Lymphatic capillaries are blind beginning.
Large lymphatic vessels return lymph to blood via what blood vessels?
Right and Left Subclavian Veins
Excess interstitial fluid
What anatomical structures found in lymph capillaries help reduce edema?
Valves, and the high permeability of capillaries.
What physiological aids help return the lymph to the blood?
Muscle pump, Lower pressure in thoracis region, and contraction of smooth muscle in lymph vessels called Peyers Patches.
What is the function of MALT?
What are some functions of lymph nodes?
Produce and house lymphocytes, filter lymph via macrophages.
List four functions of the Spleen.
Destroy old RBC's, Produce lymphocytes (WBC), filters blood, and sympathetic stimulation causes it to release blood to the circulation (Blood Reservoir).
Can a person live without a Spleen?
Yes. Liver and other lymphatics will compensate.
During what period of life is the Thymus Gland most important?
Youth. Produces lymphocytes to fight bacteria that is new to the developing immune system.
What is the function of the Thymus Gland?
Define Innate Immunity.
The body's own built in barrier, which recognizes and destroys foreign substances.
Examples of Mechanical means of Innate Immunity.
Keratin of skin, Mucus, Urine flow, coughing and sneezing.
Examples of chemical means of Innate Immunity.
Tears, Gastric Juice, Sebaceous Glands.
Compare and contrast complement and interferon.
- Complement: Proteins activated by invaders
- Interferon: Proteins produced by cells infected.
- Complement: Cause inflammation, promote phagocytosis, and lyse bacteria.
- Interferon: Promotes anti-viral activity in nearby cells, thus protecting, but does not save infected cells.
White Blood Cells and their functions.
- Neutrophils: First cells to enter infected tissue.
- Monocytes & Macrophages: Monocytes leave blood and become Macrophages, which are large phagocytic cells that produce complement and interferon.
- Basophils and Mast cells: Promote inflammation.
- Eosinophils: Contain and reduce inflammation
- Natural killer cells: Lyse tumors and virus infected cells
- Causes: Histamine, complement, certain prostoglandons (chemical mediators).
- Effects: Vasodilation (increase blood flow), Chemotaxis (attract WBC's to area, Increase vascular permeablilty (increase number of WBC's to damaged tissues.)
- Local Effects: Local inflammation, redness, swelling, pain, loss of func., confined to specific area.
- Systemic Effects: Systemic inflammation=Local symptoms plus fever, shock, could lead to death.
What is the function of fever? What causes a fever?
- Function: Elevated temp. increases rate of chemical reaction.
- Causes: Pyrogens produced by foreign invaders, or WBC's.
Define Adaptive Immunity
- Antibody-mediated immunity & Cell-mediated immunity.
- Remembers, recognizes, and improves immunity.
Compare and Contrast Antigen and Antibody
- Antigen (Ag): Molecule capable of eliciting an antibody attack when foreign antigens are present. ie: bacteria, viruses, pollen, animal dander, food and drug allergen.
- Antibodies (Ab): Proteins produced by B lymphocytes in response to a specific foreign antigen, capable of binding antigen specifically. Binds to Ag in variable regions and activates compliment cascade (inflammation, chemotaxis, lysis) in constant regions.
3 classes of Antibodies: Highest serum percentage to least.
Where are antibodies most effective when attacking an antigen?
- Effectiveness of Ab: Attacks antigens in solution or on cell surfaces.
- (Bacteria/viruses that are not inside cells, such as toxins or
5 Effects of Antibodies
- -Inactivates antigens
- -Bind antigens together
- -Activates complement cascade (lysis, chemotaxis, inflammation)
- -Stimulate release of inflammatory chemicals
- -Facilitate phagocytosis
Describe Primary and Secondary responses
Through responses by Original B cell : lymphocytes responsible for Ab mediated immunity, Plasma Cells: Derived from B cells and produce the Ab, and Memory cells: Protect against next exposure to antigen.
Define Cell-Mediated immunity, and what is it most effective against.
Specific defense provided directly by T-lymphocytes (T-cells).
Effective against: Intracellular viruses, bacteria, fungi, transplants, Cancer cells and tumors.
Types of T-cells and their functions
- Cytotoxic T-cells: to recruit macrophages to lyse cells
- Memory T-cells: Prepare body for the next invasion.
- Helper T-cells: Stimulate both B and T cells.
List the 4 types of Adaptive Immunity
- Active Natural Immunity: Ab made after natural exposure to antigen. ex: Chicken pox recovery } Own immune system
- Active Artificial Immunity: Ab are made after immunization with weakened antigen ex: Vaccine } Own immune system
- Passive Natural Immunity: Ab are received from mother in utero or via breast milk. } Ab transplanted into
- Passive Artificial Immunity: Ab from donors are injected against the antigen } Ab transplanted into
Antibodies that are formed against ones own antigens. Ex: Rheumatoid Arthritis, MS, Lupus.