Inflammation, Immunity & Sepsis – Key Vocabulary

Seventy-five key vocabulary cards summarizing essential terms from the lecture on body defenses, inflammatory response, sepsis recognition and immune mechanisms. Review to strengthen understanding before the exam.

Skin

Body’s first physical barrier to infection; must remain intact, moist and un-cracked to function fully.

Mucous membranes

Pink, moist linings of body cavities that trap microbes; dryness increases infection risk.

Cilia

Microscopic hair-like projections (e.g., in nose/airways) that sweep debris and pathogens away.

Gastric acid

Stomach secretion with pH ≈1–5 that destroys ingested microbes before they enter intestines.

Antacid

Drug that neutralizes stomach acid; excessive use can lower natural gastric defense.

Proton Pump Inhibitor (PPI)

Medication (e.g., Prilosec, Protonix) that suppresses acid production, reducing gastric antimicrobial action.

Immunoglobulins

Large protective proteins (antibodies) produced by B cells; include IgG, IgA, IgM, IgE, IgD.

Hypogammaglobulinemia

Deficiency of immunoglobulins that leaves patient immunocompromised.

IgG

Most abundant antibody; provides long-term protection and crosses placenta.

IgA

Antibody found in mucous, saliva, tears and breast milk; guards body entrances.

IgM

First antibody formed in a new infection; excellent at agglutinating microbes.

IgE

Antibody involved in allergic reactions and defense against parasites.

IgD

Surface antibody on B cells that helps initiate immune response.

Leukocytes

White blood cells; overall cellular defenders against infection.

Macrophages

Large phagocytic leukocytes that ‘eat’ debris and pathogens; called the body’s Pac-Man.

Phagocytosis

Process by which cells (e.g., macrophages) engulf and digest microbes or particles.

Lysosome

Enzyme-filled organelle whose chemicals break down bacterial walls during phagocytosis.

Enzyme

Protein catalyst; in immunity many act like ‘fire’ to destroy pathogens.

Interferon

Antiviral protein that inhibits viral replication within host cells.

Inflammatory response

Protective reaction to injury/infection characterized by redness, heat, swelling and pain.

Vascular response

First inflammatory phase where blood vessels dilate and increase flow to injured area.

Inflammatory exudate

Fluid (plasma + cells) that leaks into tissue during inflammation, causing swelling.

Plasma

Liquid portion of blood rich in proteins that nourish tissue and support healing.

Plasma proteins

Albumin, globulins, clotting factors etc.; critical for immunity and tissue repair.

Globulins

Plasma proteins that include antibodies and aid in healing.

Redness (rubor)

Visible sign of increased blood flow within inflamed tissue.

Swelling (tumor)

Accumulation of exudate and plasma in inflamed area.

Warmth (calor)

Heat felt over inflamed tissue due to vasodilation and metabolic activity.

Pain (dolor)

Possible inflammatory symptom caused by nerve irritation and swelling.

Local infection

Infection confined to one area showing redness, warmth, swelling, possible pain.

Systemic infection

Spread of microbes throughout body; manifests with whole-body signs like fever and tachycardia.

SIRS (Systemic Inflammatory Response Syndrome)

Heightened, body-wide inflammatory state that can precede sepsis.

Sepsis

Life-threatening organ dysfunction caused by dysregulated response to infection.

Severe sepsis

Sepsis accompanied by organ damage such as renal failure or altered mentation.

Septic shock

Sepsis with persistent hypotension requiring fluid resuscitation and vasopressors.

Multi-system organ failure

Failure of two or more organs following uncontrolled infection/shock; often fatal.

Fever threshold (100.4 °F)

Core temperature at or above which nurses suspect infection/sepsis per lecture.

Tachycardia

Heart rate above normal (often >90–100 bpm) indicating stress or infection.

Malaise

General feeling of weakness or discomfort common during systemic infection.

Chills

Shivering episode occurring as body temperature rises during infection.

Nausea and vomiting

GI symptoms that may accompany sepsis and contribute to fluid/electrolyte loss.

Decreased urine output

Early sign of kidney hypoperfusion seen in sepsis.

Hypotension

Low blood pressure arising in sepsis; may require fluids and vasopressors.

Fluid resuscitation

Rapid IV infusion (e.g., normal saline) to restore blood pressure in shock.

Oxygen therapy

Supplemental O₂ given to support tissues during systemic infection.

Complete Blood Count (CBC)

Lab test measuring red cells, white cells and platelets to assess infection.

Differential count

Breakdown of WBC types (neutrophils, eosinophils, etc.) that guides diagnosis.

Blood culture

Lab test to identify bloodstream pathogens and guide antibiotic choice.

Lactate level

Serum marker; elevation signals tissue hypoxia and impending sepsis.

Electrolytes

Serum ions (Na⁺, K⁺, etc.) monitored because imbalance worsens sepsis.

Potassium (K⁺)

Key electrolyte that may fall with vomiting or shift during fluid therapy.

Sodium (Na⁺)

Primary extracellular ion; may drop with fluid loss or rise with dehydration.

Broad-spectrum antibiotic

Drug active against wide range of bacteria; started before culture results.

Vancomycin

Potent antibiotic used against resistant gram-positive organisms like MRSA.

Zyvox (Linezolid)

Powerful broad-spectrum antibiotic often chosen for serious infections.

Normal WBC count

Reference range 5,000–10,000 cells/µL; elevation suggests infection.

Sed rate (ESR)

Erythrocyte sedimentation rate; nonspecific marker of inflammation (elevated >20-30 mm/hr).

Antibody titer

Lab measurement of specific antibodies indicating exposure or immunity level.

Gram stain

Lab dye technique that classifies bacteria as gram-positive or gram-negative.

Culture and sensitivity (C&S)

Test that identifies microorganism and determines which antibiotics will kill it.

Passive immunity

Short-term protection gained by receiving antibodies (e.g., via colostrum or Ig infusion).

Active immunity

Long-term defense generated by one’s own immune system after infection or vaccination.

Innate (natural) immunity

Genetic, inborn defenses present from birth, independent of exposure.

Acquired immunity

Protection developed after exposure to a pathogen or immunization.

Colostrum

Antibody-rich first breast milk that passes passive immunity to newborns.

Vaccine

Biologic agent that stimulates production of protective antibodies without causing disease.

Herd immunity

Community-level protection achieved when enough individuals possess immunity to halt spread.

Spleen

Large lymphoid organ filtering blood and contributing to immune response.

Thymus gland

Mediastinal gland where T lymphocytes mature and differentiate.

Lymphatic system

Network of vessels, nodes and tissues that returns fluid to blood and supports immunity.

T cells

Lymphocytes responsible for cell-mediated immunity and killing infected cells.

B cells

Lymphocytes that mature into plasma cells and secrete antibodies.

Humoral immunity

Antibody-mediated defense provided by B cells and immunoglobulins.

Cell-mediated immunity

Defense involving T cells that attack infected or abnormal cells directly.

Urosepsis

Sepsis originating from urinary tract infection, especially dangerous in the elderly.