Microbiology Exam 3: Chapter 9, 10, 11

Skin Defense Mechanisms

Physical defenses of the skin.

Mucous Membrane

A layer of protective tissue lining various body cavities.

Goblet Cells

Cells that secrete mucus.

Ciliary Escalator

Mechanism by which mucus and trapped particles are moved out of the respiratory tract.

Sebum

An oily substance that helps lubricate the skin and hair.

Acid Mantle

A thin, protective film on the skin's surface that helps maintain a slightly acidic pH.

Lysozyme

An enzyme that breaks down bacterial cell walls.

Defensins

Antimicrobial peptides that help defend against microbial invasion.

Cytokines

Small proteins that play a role in cell signaling and immune responses.

Autocrine

Cell signaling in which a cell responds to signaling molecules it produces itself.

Paracrine

Cell signaling in which a cell responds to signaling molecules produced by nearby cells.

Endocrine

Cell signaling in which a cell responds to signaling molecules produced by distant cells.

Interleukins

Cytokines that mediate communication between leukocytes.

Chemokines

Cytokines that induce chemotaxis, the movement of cells towards or away from a chemical stimulus.

Interferons

Cytokines that interfere with viral replication and help regulate immune responses.

Histamine

A compound released by cells in response to injury or allergic reactions, causing inflammation and vasodilation.

Leukotrienes

Inflammatory mediators that play a role in allergic and asthmatic reactions.

Erythrocytes

Red blood cells that transport oxygen and carbon dioxide.

Leukocytes

White blood cells that play a role in immune responses.

Thrombocytes

Platelets that are involved in blood clotting.

Hematopoiesis

The process of blood cell formation.

Granulocytes

A type of leukocyte with granules in the cytoplasm.

Neutrophils

The most abundant type of white blood cell, involved in phagocytosis and the initial immune response to infection.

Eosinophils

White blood cells involved in immune responses to parasites and allergic reactions.

Basophils

White blood cells involved in allergic reactions and inflammation.

Mast Cells

Cells that release histamine and other inflammatory mediators.

Degranulation

The release of granules from cells.

N.E.T.S

Neutrophil extracellular traps, structures composed of DNA and antimicrobial proteins that help trap and kill pathogens.

Agranulocytes

A type of leukocyte without granules in the cytoplasm.

Macrophages

Large phagocytic cells that engulf and destroy pathogens.

Dendritic Cells

Antigen-presenting cells that capture and present antigens to T cells.

Diapedesis

The process by which white blood cells squeeze through the walls of blood vessels and enter tissues.

Pathogen-Associated Molecular Pattern

Molecules associated with pathogens that are recognized by the innate immune system.

Pattern Recognition Receptors

Receptors on immune cells that recognize pathogen-associated molecular patterns.

Toll-Like Receptors

A type of pattern recognition receptor that plays a key role in the innate immune response.

Inflammation

A localized response to tissue damage or infection, characterized by redness, heat, swelling, and pain.

Fever

An elevated body temperature that helps fight infection.

Pyrogens

Substances that cause fever.

Effector Response

The response of the adaptive immune system to eliminate pathogens.

Anamnestic Response

A rapid and enhanced immune response upon re-exposure to a pathogen.

Natural Immunity

Immunity that is present without prior exposure to a pathogen.

Artificial Immunity

Immunity that is acquired through medical intervention, such as vaccination.

B Cells

White blood cells that produce antibodies.

T Cells

White blood cells that play a role in cell-mediated immunity.

Major Histocompatibility Complex

A set of genes that encode cell surface proteins involved in antigen presentation.

Human Leukocyte Antigen Complex

The MHC in humans.

MHC I

A type of MHC molecule found on the surface of all nucleated cells.

MHC II

A type of MHC molecule found on the surface of antigen-presenting cells.

Antigen-Presenting Cells

Cells that capture, process, and present antigens to T cells.

Antigens

Molecules that can elicit an immune response.

Antigenic Determinant

The specific part of an antigen that is recognized by an antibody or T cell receptor.

Epitopes

The small, accessible parts of an antigen that are recognized by antibodies or T cell receptors.

Haptens

Small molecules that can bind to antibodies but are not immunogenic on their own.

Endogenous Processing

The process by which antigens from within a cell are presented on MHC I molecules.

Exogenous Processing

The process by which antigens from outside a cell are taken up, processed, and presented on MHC II molecules.

Lymphocyte Maturation

The process by which lymphocytes develop and acquire their functional capabilities.

Immunocompetence

The ability of the immune system to respond to antigens.

Self Tolerance

The ability of the immune system to recognize and tolerate self-antigens.

Positive Selection

The process by which T cells with receptors that can recognize self-MHC molecules are selected to mature.

Negative Selection

The process by which T cells with receptors that strongly bind to self-antigens are eliminated.

Clonal Deletion

The elimination of self-reactive lymphocytes during development.

Clonal Selection

The process by which an antigen selectively activates and expands specific lymphocytes.

Antibodies

Proteins produced by B cells that bind to specific antigens.

IgG

The most abundant class of antibodies in the blood, involved in secondary immune responses.

IgM

The first class of antibodies produced during an immune response, involved in primary immune responses.

IgA

An antibody found in secretions such as tears, saliva, and breast milk, providing localized immunity.

IgD

An antibody found on the surface of B cells, involved in antigen recognition.

IgE

An antibody involved in allergic reactions and defense against parasites.

Critical

Items that come into contact with sterile tissues or the vascular system and must be sterile.

Semi-critical

Items that come into contact with mucous membranes or non-intact skin and require high-level disinfection.

Non-critical

Items that come into contact with intact skin and require low-level disinfection.

Bacteriostatic

Agents that inhibit the growth of bacteria.

Bactericidal

Agents that kill bacteria.

Relative resistance of microbial forms

The susceptibility of different types of microorganisms to physical and chemical control methods.

Heat

A physical control method that can be used to kill or inactivate microorganisms.

Thermal Death Point

The lowest temperature at which all microorganisms in a liquid suspension are killed in 10 minutes.

Thermal Death Time

The minimal time required to kill all microorganisms in a liquid suspension at a given temperature.

D value

The time required to kill 90% of microorganisms at a given temperature.

Moist Heat Sterilization

A method of sterilization that uses steam under pressure to kill microorganisms.

Autoclave

A device used for steam sterilization.

Dry Heat Sterilization

A method of sterilization that uses high temperatures to kill microorganisms.

Flaming

A method of dry heat sterilization that uses an open flame.

Incineration

A method of dry heat sterilization that uses extremely high temperatures to completely burn and destroy microorganisms.

Hot-Air

A method of dry heat sterilization that uses hot air to kill microorganisms.

Low Temperature

A physical control method that can slow down or inhibit the growth of microorganisms.

Lyophilization

A method of low-temperature preservation that involves freeze-drying.

Radiation

A physical control method that can kill or inactivate microorganisms.

Ionizing Radiation

Radiation that has enough energy to remove tightly bound electrons from atoms, causing damage to DNA and other cellular components.

Non-ionizing Radiation

Radiation that does not have enough energy to remove tightly bound electrons from atoms, but can still cause damage to DNA.

Mutations

Changes in the genetic material of an organism.

Point Mutation

A mutation that involves a change in a single nucleotide base.

Frameshift Mutation

A mutation that involves the addition or deletion of nucleotide bases, causing a shift in the reading frame of the genetic code.

Pyrimidine Dimers

Covalent bonds formed between adjacent pyrimidine bases in DNA, caused by exposure to UV radiation.

Phenolics

Chemical compounds derived from phenol that have antimicrobial properties.

Joseph Lister

The first person to utilize phenol in a medical application as an antiseptic.

Mode of Action

The way in which a chemical or drug exerts its effect on microorganisms.

Range

The spectrum of microorganisms that a particular chemical or drug is effective against.

Phenol

A chemical compound with antimicrobial properties.

Phenolic

A compound derived from phenol that has antimicrobial properties.

Triclosan

A phenolic compound commonly used in antibacterial soaps and other personal care products.