Lymphatic System and Immunity Flashcards
What is the function of lymph?
- absorb dietary fat and deliver to bloodstream
- collection of excess interstitial fluids
- delivers excess fluid to bloodstream
- delivers foreign particles to lymph nodes
How is lymph moved?
- skeletal muscle action
- respiratory movement
- smooth muscle in larger lymphatic vessels
- valves in lymphatic vessels
What is function of lymph nodes?
- filter potentially harmful particles from lymph
- immune surveillance by macrophages & lymphocytes
- produces lymphocytes
What does the thymus do?
- produces T lymphocytes
- secretes thymosins
Important to know about the spleen?
- largest lymphatic organ
- located in upper left abdominal quadrant
- sinuses filled with blood
- contains white pulp (lymphocytes)
- contains red pulp (RBC, lymphocytes, macrophages)
What are pathogens?
disease causing agent (bacteria, virus, complex microorganism, spores of multicellular organism)
What is innate defenses?
General defenses that protect against many pathogens, this is nonspecific immunity
What is adaptive defenses?
- specific immunity
- carried out by lymphocytes
What are the mechanisms for nonspecific immunity?
- mecanical barrieers (skin, mucous membrane)
- chemical barriers (enzymes, pH)
- Natural killer cells
- inflammation (prevents the spread of infectious agents)
- phagocytosis
- fever
What are the mechanisms for specific (adaptive) immunity?
- resistance to particular pathogens or to their toxins or metabolic by-products
- is based on the ability to distinguish “self” from “non-self”
- antigens elicit immune response
- most effective antigens are large and complex
What are Haptens?
small molecules that are not antigenic by themselves
T cells and B cells original where?
Red Bone Marrow
T cell and B cells are differentiated where?
T cells - thymus
B cells - red bone marrow
Primary locations of T cells and B cells are?
lymphatic tissues and blood.
- T cells (70-80% of lymphocytes in blood)
- B cells (20-30% of lymphocytes in blood)
Do T cells and B cells provide direct or indirect immunity defense?
- T cells attack directly
- B cells are indirect, they produce antibodies to attack
Steps of B cell antibody production.
- antigen-bearing agent enters tissue.
- B cell activated when if encounter an antigen that B cell fits its receptor.
- Either alone, or with helper T cell, B cell proliferates
- Some of B cell differentiates further into plasma cells.
- Plasma cells synthesize and create antibodies
- antibodies combine with antigen-bearing agents, helping to destroy them.
Steps of T cell antibody production.
- antigen-bearing agent enters tissue.
- an accessory cell (ex: macrophages) phagocytize’s (basically eats) the antigen and lysosomes digest it.
- the digested antigen is displayed on the surface of the accessory cell.
- Helper T cells are activated when they encounter accessory cells that have digested antigen on surface.
- Activated helper T cells release cytokines when it encounter a B cell that was previously combined with antigen-bearing agent.
- Cytokines stimulates the B cell to proliferate.
- Some of the simulated B cells differentiates further into antibody-secreting plasma cells.
- antibodies combine with antigen destroying them.
An underactive immune system or immunodeficiency disorder can be caused by?
- virus
- chemotherapy
- immunosuppressive drugs
- use of corticosteroids
A hypersensativity disorder is caused by what?
an overreactive response to a normally benign foreign substance.
An autoimmune disorder is caused by what?
when immune system cannot distinguish “self” from “non-self”
A immunoproliferation disorder is caused by what?
an abnormal reproduction or multiplication of cells; leukemia or lymphoma
What is common with both forms of passive immunity?
short-term effects with out stimulating an immune response.
Artificial active immunity differs from natural active immunity how?
both stimulate an immune response; artificial active immunity is without server symptoms whereas natural active immunity does.
Type 1 allergic reaction
Immediate-reaction allergy
- occurs minutes after contact with allergen
- example: hives, hay fever, asthma, anaphylactic shock
Type 2 allergic reaction
Antibody- dependent cytotoxic reaction
- takes 1 to 3 hours to develop
- example: transfusion reaction
Type 3 allergic reaction
Immune-complex reaction
- takes 1 to 3 hours to develop
- antibody complexes cannot be cleared
- damage to body tissues
Type 4 allergic reaction
Delayed-reaction allergy
- results from repeated exposure to allergen
- eruptions and inflammation of the skin
- takes about 48 hours to occur
Life-span changes to immune system
- declines early in life when thymus gland shrinks
- higher risk of infections
- slower antibody response
- IgA and IgG antibodies increase
- IgM and IgE antibodies decrease
IgG is found where?
Plasma and tissue fluid; defends against bacteria, virus, toxins
IgA is found where?
exocrine gland secretions; defends against bacteria and virus
IgM is found where?
Plasma; reacts to antigens on some RBC
IgD is found where?
surface of most B lymphocytes; B cell activation
IgE
exocrine gland secretions; promotes inflammation and allergic reactions
