Exam 5 Study Guide: Innate Immune System

A comprehensive study guide containing flashcards on the innate immune system, inflammation, cytokines, and antibiotic resistance.

Innate Immune System

The first line of defense against pathogens, composed of physical and chemical barriers.

First Line of Defense

Physical barriers that keep pathogens on the outside or neutralize them before infection.

Second Line of Defense

Responses that slow or contain infections when the first line of defense fails.

Physical Barriers

Barriers to entry like skin and mucous membranes that remove microbes from the body.

Chemical Barriers

Substances like sebum and gastric juice that destroy microbes.

Mucous Membrane

Tissue that secretes mucus to trap microbes and protect surfaces.

Gastric Juice

Highly acidic fluid in the stomach that destroys most bacteria.

Normal Bacteria

Beneficial microbes that inhibit or kill pathogenic bacteria.

Escherichia coli

Bacteria in the large intestine that produces bacteriocins to inhibit pathogens.

Lactobacillus

Bacteria that produce hydrogen peroxide in the vagina to inhibit pathogens.

Mast Cells

Cells that release chemicals to activate inflammation.

Neutrophils

Type of phagocyte that functions in ingesting and destroying pathogens.

Basophils

Cells that produce histamine as part of the immune response.

Eosinophils

Cells that produce toxic proteins against parasites and can act in phagocytosis.

Monocytes

Blood cells that mature into macrophages, which are phagocytic.

Dendritic Cells

Cells that present antigens and initiate adaptive immune responses.

Natural Killer (NK) Cells

Lymphocytes that destroy virus-infected and cancerous cells.

Phagocytosis

The process by which a cell engulfs a microorganism or other substances.

Chemotaxis

The movement of phagocytes toward microorganisms in response to chemicals.

Pseudopods

Extensions of a phagocyte's plasma membrane that engulf pathogens.

Phagosome

Sac formed around a microorganism during phagocytosis.

Phagolysosome

The fusion of a phagosome with a lysosome for digestion of ingested microbes.

Residual Body

The indigestible material left after phagocytosis that is expelled from the cell.

Microbial Evade Mechanisms

Strategies like capsules and biofilms that protect microbes from phagocytosis.

Inflammation

The body's response to tissue damage characterized by redness, heat, pain, and swelling.

Acute Inflammation

Sudden onset of inflammation that lasts a few days or weeks.

Chronic Inflammation

Slow-developing inflammation that can last months or years.

Pyrexia

An abnormally high body temperature, also known as fever.

Hypothalamus

The brain area that regulates body temperature and can trigger fever.

Interleukin-1

A cytokine released by phagocytes that raises the hypothalamic set point.

Complement System

A system of over 30 proteins that enhance the immune response by destroying microbes.

Activated Complement Fragments

Splits of complement proteins that carry out destructive actions in immune response.

Cytokines

Soluble proteins produced by immune cells that regulate immune responses.

Interferons

Cytokines that interfere with viral infections by signaling neighboring cells.

Chemokines

Cytokines that induce movement of immune cells to areas of infection.

Tumor Necrosis Factor

Cytokines that have a direct toxic effect on tumor cells and are involved in inflammation.

Antigens

Substances that induce an immune response by producing antibodies.

Epitopes

Specific regions on antigens where antibodies bind.

Antibodies

Y-shaped molecules that attach to antigens and help neutralize pathogens.

IgG

The most common antibody class found in blood and tissues.

IgM

The first antibody class produced by B cells, often found as a pentamer.

IgA

Antibodies found in body secretions, protecting mucosal surfaces.

IgD

An antibody class present in small amounts, mainly on B cell surfaces.

IgE

Antibodies involved in allergic reactions and defense against parasitic infections.

B-Cells

Immune cells that produce antibodies upon activation by antigens.

T-Cells

Cells that act in cell-mediated immunity and recognize antigenic peptides.

T-Helper Cells

T cells that assist B cells and activate other immune cells.

Cytotoxic T Cells

T cells that recognize and kill virus-infected and cancerous cells.

Memory T Cells

Long-lived T cells that respond quickly upon re-exposure to antigens.

Natural Killer Cells (NK Cells)

Innate immune cells that kill infected or cancerous cells without prior sensitization.

Primary Immune Response

The initial slow response of the immune system to a first exposure to an antigen.

Secondary Immune Response

A faster and stronger response upon re-exposure to an antigen due to memory cells.

Natural Immunity

Immunity acquired through infection or maternal antibodies (active or passive).

Artificial Immunity

Immunity gained through medical intervention like vaccines (active) or antibody injections (passive).

Bacteriostatic Drugs

Antibiotics that inhibit bacterial growth but do not kill bacteria.

Bactericidal Drugs

Antibiotics that kill bacteria outright.

Quinolones

Drugs that inhibit bacterial DNA gyrase, preventing replication.

Rifamycins

Drugs that block RNA polymerase, stopping transcription in bacteria.

Polyenes

Antifungals that bind ergosterol in fungal membranes causing cell leakage.

Echinocandins

Antifungal drugs that inhibit the formation of the fungal cell wall.

Interferons

Proteins produced by host cells that limit viral spread by signaling nearby cells.

Neuraminidase Inhibitors

Antiviral drugs that prevent the release of new influenza virus particles.

Selective Toxicity

The ability of a drug to target pathogenic organisms without harming the host.

Antibiotic Resistance

The ability of bacteria to survive and reproduce despite antibiotic treatment.

Misuse of Antibiotics

Practices like incomplete prescriptions or using antibiotics for viral infections that promote resistance.