Exam 1 Patho

Atrophy

Decrease in cell size (number stays same).

Hypertrophy

Increase in cell size.

Hyperplasia

Increase in number of cells.

Metaplasia

Replacement of one mature cell type with another.

Dysplasia

Abnormal changes in cell size, shape, and organization.

Hypoxia

Lack of sufficient oxygen within cells.

Free radicals

Unstable atoms with unpaired electrons causing cell damage.

Apoptosis

Programmed cell death, non-inflammatory.

Necrosis

Unregulated cell death causing inflammation.

Ischemia

Reduced blood supply to tissues.

Oxidative stress

Damage from free radicals during reperfusion of ischemic tissue.

Cellular accumulations

Build-up of substances within cells due to sustained injury.

Autophagy

Self-eating via autophagic vacuoles.

Necrosis types

Coagulative (kidney/heart), Liquefactive (brain), Caseous (TB), Fat (pancreas), Gangrene.

Apoptosis vs Necrosis

Apoptosis = regulated and clean; Necrosis = unregulated and inflammatory.

Pathogen

Disease-producing microbe.

Pathogenicity

Ability to cause disease.

Virulence

Degree of pathogenicity.

Infectivity

Proportion of exposures needed to cause infection.

Toxigenicity

Ability of a pathogen to produce toxins.

Antigenic variation

Pathogen's ability to alter antigens to evade host immunity.

Biofilms

Microbial communities protected by sticky matrix.

Sepsis

Life-threatening body-wide response to infection.

Endotoxin

Toxin from Gram-negative bacterial cell walls.

Exotoxin

Proteins secreted by bacteria that damage host cells.

Superantigen

Exotoxin that causes excessive immune response.

Opportunistic infection

Disease in immunocompromised host.

Antimicrobial resistance

Microbes’ ability to withstand drugs.

Vaccination

Training immune system with antigens.

Immunocompromised host

Person with weakened immune defenses.

Adaptive immunity

Specific, learned defense with memory.

Antigen

Substance recognized as foreign.

Antibody (immunoglobulin)

Protein that binds antigens.

B lymphocytes (B cells)

Cells that make antibodies.

T lymphocytes (T cells)

Cells that regulate or kill infected cells.

Helper T cells (CD4+)

Activate immune responses.

Cytotoxic T cells (CD8+)

Destroy infected or cancerous cells.

Clonal selection

Lymphocyte proliferation against antigen.

MHC

Cell surface proteins presenting antigens.

Humoral immunity

Antibody-mediated defense.

Cell-mediated immunity

T-cell-driven defense.

Memory cells

Long-lived cells enabling quick future responses.

Primary vs Secondary immune response

First = slow/weak, Secondary = fast/strong.

Active vs Passive immunity

Active = self-produced, Passive = borrowed protection.

Primary immunodeficiency

Genetic defect causing impaired immunity.

Secondary immunodeficiency

Acquired immune weakness from disease or environment.

Hypersensitivity

Excessive or inappropriate immune response.

Autoimmunity

Immune system attacks self-tissues.

Alloimmunity

Immune response against transplanted tissue or cells.

Anaphylaxis

Severe, life-threatening allergic reaction.

Molecular mimicry

Foreign antigens resemble self-antigens.

Immune complex

Antigen–antibody cluster depositing in tissues.

Graft rejection

Immune destruction of transplanted tissue.

HLA

Genetic markers for immune recognition and compatibility.

Cancer

Uncontrolled abnormal cell growth with potential to spread.

Benign tumor

Non-invasive, slow-growing, well-differentiated.

Malignant tumor

Fast-growing, poorly differentiated, invasive, metastatic.

Carcinoma in situ

Pre-invasive epithelial tumor.

Oncogene

Mutated proto-oncogene promoting cell growth.

Tumor suppressor gene

Gene that inhibits cell growth.

Mutation

Change in DNA sequence.

Epigenetics

Changes in gene expression without DNA sequence alteration.

Metastasis

Spread of cancer to distant sites.

Angiogenesis

Formation of new blood vessels for tumors.