Ch. 16 Flashcards
Define pathogen.
disease causing agents
What role does the lymphatic system play in moving body fluids?
moves interstatial fluid to the blood stream
A lymphatic vessel is most similar to what?
veins
From the collecting ducts, lymph enters _____ and becomes part of the _____
veins, plasma
In what situation will there be an increase in lymph formation?
Increase in hydrostatic pressure in the tissue
How does lymph differ from plasma?
lymph has only WBC, plasma has WBC and RBC
One function of lymph
transports foreign particles, such as bacteria, to lymph nodes
Tissue fluid is formed when fluid ____ and lymph is formed when fluid______
is forced out of blood plasma ; enters lymph capillaries
The region of a lymph node through which blood vessels and nerves pass is called the what?
hilum
Cervical lymph nodes filter lymph draining from what region?
memory gland, upper limbs, head, and neck
Lymph nodes are located throughout the body except in the?
central nervous system
Which cells function as phagocytes?
macrophages, dendrites, Natural Killer cells
Describe spleen appearance
large lymph node, enclosed in connective tissue and subdivides into lobules.
Name the calss of hormones that stimulate maturation of T lymphocytes.
Thymosins
Red and white pulp are found in what structure?
spleen
How can the innate defenses be characterized?
fast and non-specific
How do viruses differ from other pathogens?
They cannot reproduce outside of a living cell.
The redness and swelling that occurs with inflammation is due to what changes in the infected/injured tissue?
Increase in blood flow and capillary permeability
What cells make up the mononuclear phagocytic system?
monocytes adn macrophages
Virus-infected cells release ____ that function to protect nearby cells from becoming infected
interferons
What type of phagocytic cells are circulating in the blood?
neutrophils and monocytes
What is the effect of interleukin-1 secretion?
fever
Mucus, tears, saliva, and hair are all examples of what type of defense against potential pathogens?
mechanical barriers
What defense mechanism responds to the presence of foreign antigens by initiating a cascade of reactions, resulting in inflammation and enhanced phagocytosis in the area?
complement system
Why is a short-term low-grade fever an effective innate defense?
Increases body temp which enhances effect of phagocytes.
What responses to a pathogen are slower but more specific?
adaptive immune system
What occurs during an adaptive immune response?
production of antibodies
Following a tissue transplant, recipients typically need to take medication to what?
suppress their immune system
What cell types are primarily responsible for immunity?
lymphocytes, macrophages
T lymphocytes are responsible for what aspect of defense against infection?
cellular immune response
What type of immunoglobulin is the most abundant of the circulating antibodies?
G (IgG)
What is the target of cytotoxic T cells?
cancers
How do cytotoxic T cells destroy their targeted cells?
releasing perforin, which pokes holes, triggering apoptosis (cell death)
Newborns can be protected against certain digestive and respiratory infections when the receive ___ via their mother’s milk
IgA
Antigen-presenting cells engulf and digest an antigen, then insert antigen fragments on their cell surfaces in association with _____?
class 2 MHC proteins
Rheumatic fever, Graves’ disease and systemic lupus erythematosus are examples of what types of diseases?
autoimmune
What is the relationship between antigens and antibodies?
presence of antigen triggers production of antibodies
What is the function of plasma cells?
produce antibodies
What occurs during a primary immune response?
antibody concentration slowly increases, peaking at 10-12 days post exposure
What is the result of a cellular immune response?
T cells attach, attack foreign antigens and destroy them
How does a vaccine produce its effects?
antigens stimulates, primary immune response
Following contact with its targeted antigen, a B cell will divide and differentiate into ___ ___, which produce and secrete antibodies.
plasma cells
Antibody actions against antigens include _____, in which the antibodies bind to antigen, forming an insoluble complex that can be phagocytized.
precipitation
What is opsonization?
process of coding antigen with proteins to make it more easily phagocitized
Immune cells called ____ are activated when their antigen receptors bind to displayed foreign antigens. They will then release cytokines that function to continue the immune response.
Helper T cells
If a vaccine is given to most people in a population, it can halt the spread of an infection because of what?
herd immunity
What part of an antibody molecule binds to its targeted antigen?
ends of molecules with light and heavy chain variables
What occurs during an adaptive immune response?
Production of antibodies
The human immunodeficiency virus (HIV) targets ____, which explains why both the humoral and cellular immune responses become inefficient as a result of HIV infection
Helper T cells
Anaphylactic shock is a risk with what type of hypersensitivity?
Type 1
