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22.6: Key Terms

  • Page ID
    111487
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    acquired immunodeficiency syndrome (AIDS)
    latest and most severe stage of HIV, characterized by a low CD4 cell count and opportunistic infections
    adaptive immune response
    relatively slow but very specific and effective immune response controlled by lymphocytes
    antibiotic resistance
    increased ability of microorganisms to survive exposure to antibiotic medications
    antibiotic stewardship
    efforts to improve antibiotic prescribing strategies to more effectively treat infections and avoid the development of antibiotic resistance
    antigen
    molecule on the cell surface of a pathogen that is recognized as an invader by the immune system
    barrier defense
    skin, mucous membranes, and other components of the immune system that act instantaneously to prevent pathogenic invasion into body tissues
    bone marrow
    spongy material located inside the long bones and responsible for the production and maturation of blood cells
    Clostridioides difficile
    bacterium normally located in the intestines that can cause secondary inflammation of the colon, most often after taking antibiotics; also called C. diff
    colectomy
    removal of a portion of the colon
    contagious
    capable of spreading from one person to another
    coronavirus
    type of virus characterized by a lipid envelope surrounded by proteins that jut out like spikes
    deoxyribonucleic acid (DNA)
    self-replicating material that is present in all living organisms and the main constituent of chromosomes; the focus of genetics
    fecal transplant
    transfer of medically processed stool from a healthy donor into a colon infected by Clostridioides difficile bacteria
    fungus
    organism that belongs to the kingdom Fungi, characterized by eukaryotic cells that contain cell walls and vacuoles but not chloroplasts and that typically grow as tubular, thread-like structures called hyphae
    hepatitis
    condition characterized by inflammation of the liver; often a secondary result of a viral infection
    hepatocyte
    liver cell
    host
    organism that has been infected by another organism or virus
    human immunodeficiency virus (HIV)
    retrovirus characterized by the destruction of certain white blood cells, ultimately resulting in AIDS
    immune system
    complex collection of cells and organs that destroy or neutralize pathogens that would otherwise cause disease or death
    infectious disease
    caused by pathogenic microorganisms—agents such as bacteria, viruses, parasites, or fungi—that enter a human host, multiply, and cause infection that can spread via direct or indirect transmission
    innate immune response
    rapid but relatively nonspecific immune response
    leukocyte
    primary cell of the immune system that fight off pathogens to prevent infection; also called white blood cell
    liver cirrhosis
    damage to the liver that results in permanent scarring and fibrosis
    long COVID
    condition in which an individual has recovered from COVID-19 but continues to have symptoms and adverse effects for months after infection
    lymph
    interstitial fluid once it has entered the lymphatic system
    lymph node
    small, bean-shaped organs located along lymphatic vessels
    lymphatic system
    system of vessels, cells, and organs that carries excess fluids to the bloodstream and filter pathogens from the blood
    methicillin-resistant Staphylococcus aureus (MRSA)
    strain of Staphylococcus bacteria that has become resistant to many antibiotics
    opportunistic infection
    infection that arises from pathogens that would not normally cause infection in a healthy individual but occur when the immune system is not functioning optimally
    oral thrush
    infection caused by the fungus Candida albicans, which is found normally in the mouth but can become overgrown and pathological; also called oral candidiasis
    pathogen
    agent such as a bacterium, virus, parasite, or fungus that enters a human host, multiplies, and causes infection
    pathogenicity
    potential ability of a pathogen to cause disease in a susceptible host
    retrovirus
    virus composed of a ribonucleic acid strand that can be turned into DNA and permanently inserted into a healthy cell
    reverse transcriptase
    enzyme used to convert RNA into DNA
    ribonucleic acid (RNA)
    nucleic acid that is present in all living cells and that carries instructions from DNA for controlling protein synthesis
    secondary infection
    infection that arises after treatment for a different, primary infection; also called opportunistic infections
    spleen
    secondary lymphoid organ that filters pathogens from the blood and removes damaged blood cells
    thymus
    lymphatic organ whose main function is the production of a group of hormones that contribute to the development and differentiation of T lymphocytes
    vancomycin-resistant Enterococcus (VRE)
    strain of enterococci bacteria that has become resistant to treatment with the antibiotic vancomycin
    viral load
    amount of virus in the blood
    virulence
    severity of an infectious disease
    virus
    piece of genetic code, such as DNA or RNA, protected by a coating of protein and capable of self-directed movement and reproduction

    This page titled 22.6: Key Terms is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by OpenStax.

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