_____ interact with the antigen-class II MHC complex presented by macrophages
Definition
Helper T cells
Term
B cells that have been stimulated by_____ develop into _____
Definition
interleukin-2
plasma cells
Term
The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response
Definition
perforin ... cell-mediated
Term
Perforin molecules puncture the target cell, allowing water and ions to rush inside, causing_____
Definition
swelling and lysis
Term
The branch of acquired immunity that involves the activation of cytotoxic T cells, which defend against infected cells, cancer cells, and transplanted cells.
Definition
cell-mediated immune response
Term
What is the source of a viral envelope
Definition
host cell membrane
Term
An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses.
Definition
retrovirus
Term
reverse transcriptase
Definition
An enzyme encoded by some certain viruses (retroviruses) that uses RNA as a template for DNA synthesis.
Term
Double-stranded viral DNA is incorporated into a host cell as a _____.
Definition
provirus
Term
What do macrophages and neutrophils have in common
Definition
They phagocytize pathogens
Term
Chemicals produced by virus-infected cells that alert neighboring cells to prepare a defense are called
Definition
interferons
Term
Which one of the following is part of the inflammatory response
Definition
dilation of the capillaries
Term
Complement proteins promote the release of ____and attract more phagocytes to the area.
Chemokines direct the migration of phagocytes to the site of inflammation and signal them to _____
Definition
histamine
increase production of microbe-killing compounds.
Term
Which type of cell is responsible for causing apoptosis in cancer cells and virus-infected cells?
Definition
natural killer cells
Term
a function of white blood cells that helps them carry out defensive functions more effectively
Definition
release of cytokines
Term
An immune response is initiated by the presence of which molecules?
Definition
antigen
Term
experiments, the thymus glands were removed from baby mice. Which of the following would you predict as a likely result?
Definition
The mice readily accepted tissue transplants
Term
The proliferation of the B lymphocyte to which a specific antigen binds is referred to as _____
Definition
clonal selection
Term
What is the role of dendritic cells in the primary immune response?
Definition
Dendritic cells present antigen via class II MHC molecules to young helper T cells.
Term
A group of researchers tested many chemicals and found several that have potential for use in modifying the action of the immune system. Which of the following compounds has the most promise as a drug for inhibiting transplant rejection?
Definition
compound B55: suppresses specific cytotoxic T cells
Term
Which one of the following classes of immunoglobins crosses the placenta and confers passive immunity to the fetus
Definition
It is the most abundant of circulatory antibodies and protects against microbes and toxins in the blood and lymph.
IgG
Term
A viral infection in a cell results in _____
Definition
secretion of interferon
Term
a result of antibody-antigen binding
Definition
Neutralization
Term
How do antibodies to foreign blood groups come to exist in the body?
Definition
The antibodies arise in response to bacterial inhabitants of the body that have epitopes very similar to blood groups and antigens.
Term
Besides helper T cells, what are two other types of cells that HIV infects?
Definition
macrophages and brain cells
Term
What do the antibodies secreted by plasma cells (the effector cells of humoral immunity) do to attack their targets
Definition
activate complement to form a pore in the membrane of the targets
Term
Which immune disorder is characterized by absent or nonfunctional T and B cells?
Definition
Severe combined immunodeficiency (SCID)
Term
_____ most abundant in circulation
Definition
neutrophils
Term
Basophils make up less than_____of total leukocytes (white blood cells).
Mast cells are found in _____.
_____ cells are found in tissues, lymph nodes, spleen and thymus.
Definition
1%
connective tissues and close to mucosal surfaces
Dendritic cells
Term
Which of these is a professional antigen presenting cell (APC)
Definition
dendritic cells
ingest antigens and degrade them into peptides. The peptides are fused with MHC Class II molecules and presented to T cells. Other professional APC include macrophages and B cells.
Term
How are the different isotypes of antibodies produced?
Definition
class switching
After activation, some B cells will class switch to produce a different isotype of immunoglobulin. This is controlled by cytokines secreted by T helper cells. The five different isotypes of a particular antibody all have the same specificity for a particular antigen, but they function in different parts of the body such as mucosal surfaces, tissue or blood.
Term
Necrosis
Definition
is a pathological consequence of cell injury, which can cause inflammation
Term
exudate
Definition
Transudate is an ultrafiltrate of blood which is low in protein and leaves blood vessels due to osmotic pressure in capillaries. Pus and blood can be present in inflamed areas, but they are not produced during the process.
Term
The four types of inflammation are:
Definition
The four types of inflammation are: Serous - characterised by a watery exudate e.g. bullous pemphigoid, where the skin separates from the underlying infection. Fibrinous - characterised by the presence of fibrin e.g. fibrinous pericarditis. Purulent - characterised by pus (made up of dead or dying neutrophils). Suppurative - discontinuity of the body surface e.g. ulcers.
Term
The cellular events involved in inflammation are
Definition
1) Margination - when white blood cells (leukocytes) fall out of the central axial column within the blood vessel and assume a peripheral position along the endothelium tissue. 2) Rolling - which occurs due to loose adhesion between selectin molecules and carbohydrate ligands on the leukocyte surface. 3) Adhesion - LFA-1 molecules on leukocytes develop affinity for ICAM-1 present on the endothelial surface causing the leukocytes to bind with considerable stability. 4) Diapedesis - leukocytes secrete collagenase which degrades the basement membrane causing the cells to transmigrate across the endothelium. 5) Chemotaxis - locomotion orientated along a chemical gradient. 6) Phagocytosis - leukocytes ingest solid particles by exocytosis and then digest them using lysosomes.
Term
What mediator activates the kinin system
Definition
The release of bradykinin activates the kinin system which results in increased vascular permeability, smooth muscle contraction, vasodilation of arterioles and pain
Term
Which chemical mediator causes vasoconstriction, bronchoconstriction, leukocyte adhesion, chemotaxis, degranulation and oxidative burst?
Definition
Platelet-Activating Factor (PAF)
Term
Phagocytosis is the process whereby cells ingest solid particles in an attempt to kill/remove the injurious agent.
steps?
Definition
1) Recognition and attachment - microorganisms are identified when coated by complement 2) Engulfment - the phagocyte binds to the opsonised particle and encloses it completely within a phagosome created by the cell's own cytoplasmic membrane. 3) Killing / degradation - the phagosome within the phagocyte fuses with a lysosome which then 'digests' the particle.
- progressive destruction of the affected organ - dissemination to other organs - healing by fibrosis
Term
What HIV protein helps insert the HIV provirus into the host's DNA?
Definition
integrase
Term
1) Margination 2) Rolling - 3) Adhesion - 4) Diapedesis - 5) Chemotaxis - 6) Phagocytosis - leukocytes ingest solid particles by exocytosis and then digest them using lysosomes.
Definition
1 - when white blood cells (leukocytes) fall out of the central axial column within the blood vessel and assume a peripheral position along the endothelium tissue.
2 - which occurs due to loose adhesion between selectin molecules and carbohydrate ligands on the leukocyte surface.
3 - LFA-1 molecules on leukocytes develop affinity for ICAM-1 present on the endothelial surface causing the leukocytes to bind with considerable stability.
4 - leukocytes secrete collagenase which degrades the basement membrane causing the cells to transmigrate across the endothelium.
5 - locomotion orientated along a chemical gradient.
6 - leukocytes ingest solid particles by exocytosis and then digest them using lysosomes.
Term
What are the cells on the skin called?
Definition
Melanocytes
Term
A chemical circulating in the blood that causes a rise in body temperature.
Definition
pyrogen
Term
first time you exposed to a particular antigen your plasma will produce____
later exposure ____
Definition
IgM
IgG
Term
somatic hypermutation
Definition
Somatic hypermutation (SHM) of immunoglobulin (Ig) genes is a highly specific mechanism restricted to B lymphocytes during only a few cell generations
