Overall Questions For Exam #4 Flashcards
Why does acyclovir only affect viruses and not humans?
Acyclovir is an antiviral medication used to treat infections caused by viruses( herpes, Epstein-Barr virus, etc.) It only affects viruses because the drug is selectively toxic to viral DNA polymerase, it targets and inhibits replication of virus, without causing harm to human cells.
What is the ELISA test?And what does it stand for?
ELISA (enzyme-linked immunosorbent assay)
A group of serological tests that use enzyme reactions as indicators
Extra credit:
give examples of how antibiotics become resistant, what causes bacteria to become resistant to antibiotics?
Variety of mutations can lead to antibiotic resistance:
-overuse & misuse of antibiotics include
-outdated/weakened antibiotics
-Antibiotics in animal feed
-using someone else’s antibiotics leaves body susceptible to mutants.
How does MHC affect APC?
MHC molecules are essential for the ability of APCs to present antigens to T cells. MHC molecules on the surface of APCs affects ability of T cells to recognize/respond to antigens.
What is found on both skin and mucous membranes?
Skin & mucous membranes include:
Epithelial cells
Glands that secrete sweat & mucus
Dendritic cells
Immune cells
What cell crosses capillary wall?
WBCs (leukocytes) are able to cross capillary walls through diapedesis
Which immunoglobulin crosses the placenta?
IgG is the only immunoglobulin that crosses the placenta.
What are the characteristics of antibodies?
Characteristics: 1. Specificity 2. Diversity 3. Affinity 4. Reusability 5. Ability to activate immune responses. 6. Immunological memory
What antibodies can do:
- neutralize pathogens, opsonization, complement activation, antibody- dependent cell mediated cytotoxicity, provides passive immunity
OVERALL: protects body from harmful foreign substances
What antibodies can’t do:
Can’t directly kill pathogens, can’t target/eliminate cancer cells in their own, can’t cross blood brain barrier/ reach pathogens in CNS, can’t prevent viral infections from entering host cells but they can neutralize viruses before they enter host cells
What would be found on the dermis of the skin?
Dermis of skin contains blood vessels, hair follicles, sweat glands, sebaceous glands, nerve endings, collagen&elastin fibers
Third line of defense: specialized lymphocytes:
T&B cells
Clonal selection
B cells become activated when?
an Ag reacts w specific receptors on its surface
T cell- independent antigens stimulate….
B cells directly
- larger, repeating
- exogenous
T-dependent Ags require help of 1____ & 2_____ to stimulate 3____
1 Antigen presenting cells (APCs)
2 T helper cells
3 B cells
* phagocytized by a phagocyte
* smaller not as numerous
* endogenous
Stimulates TH cells:
Interleukin-1
Activates TH, B, TC, and NK cells
Interleukin-2
Differentiation of CD4 cells
Interleukin-12
Stimulate macrophage activity:
γ- interferon
(Gama)
Induce migration of leukocytes to infection
Chemokines
Cell mediated immunity involves
Direct action of T cells
• T Helper Cells (TH) = CD4 cells
present T dependent Ags to B cells, stimulate other T & B cells
• T Cytotoxic Cells (TC) = CD8 cells
differentiate into cytotoxic T Lymphocytes (CTL) which destroy target cells with perforin
T Regulatory Cells (Treg)
suppress T cells against self subset of CD4 TH cells
formerly called T suppressor cells
Known fact of Jenners research
Known: smallpox is more dangerous than variolation, and cowpox is less dangerous than variolation
Jenners hypothesis
Infection with cowpox gives immunity to smallpox
Jenners test
If variolation after infection with cowpox fails to produce a small pocks infection, immunity to smallpox has been achieved
Jenners consequence
Immunity to smallpox can be induced much more safely than by variolation
Brief history of immunization
Chinese noticed children who recovered from smallpox did not contract the disease again. They infected children with material from a small pox scab to induce immunity.
This process is known as ??
Variolation
Variolation spread to England and America, but was stopped because of risk of death
