Immunity
Which branch of the immune system provides the body's first line of defense and responds quickly but nonspecifically to pathogens?
Innate immunity
Which antiviral drug is commonly prescribed to treat influenza A and B infections?
Answer: Oseltamivir (Tamiflu)
Rationale: Oseltamivir is a neuraminidase inhibitor that prevents the influenza virus from releasing new viral particles from infected cells.
What term describes community-wide protection when a large percentage of the population is immune to a disease?
Herd immunity
Rationale: Herd immunity occurs when enough people are immune to a disease, reducing transmission within the community.
What are the five classic signs of inflammation?
Redness, warmth, swelling, pain, and loss of function
Rationale: These signs occur because of increased blood flow, vascular permeability, and immune cell activity in injured tissues.
What life‑threatening allergic reaction causes airway swelling, hypotension, and respiratory distress?
Anaphylaxis
Rationale: Anaphylaxis is a severe Type I hypersensitivity reaction requiring immediate emergency treatment.
Which immune cells are responsible for producing antibodies after exposure to an antigen?
Answer: B lymphocytes (B cells)
Rationale: B cells differentiate into plasma cells that produce antibodies specific to an antigen, providing humoral immunity.
Antiviral medications for influenza are most effective when started within how many hours of symptom onset?
Answer: 48 hours
Rationale: Antivirals reduce viral replication most effectively when administered within 48 hours after symptoms begin.
Which type of vaccine uses a weakened form of the pathogen to stimulate immunity?
Live attenuated vaccine
Rationale: Live attenuated vaccines contain weakened pathogens that stimulate a strong immune response without causing disease.
Which chronic degenerative joint disease results from breakdown of articular cartilage?
Oesteoarthritis
Rationale: Osteoarthritis occurs due to cartilage degeneration leading to pain, stiffness, and decreased mobility.
What medication is the first‑line treatment for anaphylaxis?
Epinephrine
Rationale: Epinephrine rapidly reverses airway constriction, hypotension, and shock associated with anaphylaxis.
What type of immunity occurs when a person receives antibodies through breast milk?
Answer: Natural passive immunity
Rationale: Natural passive immunity occurs when antibodies are transferred naturally from mother to infant through breast milk or the placenta.
Which class of antiviral medications prevents viruses from leaving infected cells by inhibiting the neuraminidase enzyme?
Answer: Neuraminidase inhibitors
Rationale: Neuraminidase inhibitors block viral release from infected cells, slowing infection spread.
Which immune cells are responsible for long‑term immunity after vaccination?
Memory cells
Rationale: Memory B and T cells remain in the body after infection or vaccination and respond rapidly upon re‑exposure.
Which painful inflammatory condition results from deposition of uric acid crystals in joints?
Gout
Rationale: Gout occurs when uric acid accumulates and forms needle‑like crystals that trigger intense inflammation.
What condition involves rapid swelling of the lips, tongue, or throat due to an allergic reaction?
Angioedema
Rationale: Angioedema results from fluid leakage into tissues due to histamine release during allergic reactions.
Which type of immunity occurs after vaccination?
Answer: Artificial active immunity
Rationale: Artificial active immunity occurs when a person is exposed to antigens through vaccination, causing the immune system to produce antibodies and memory cells.
Which enzyme do retroviruses such as HIV use to convert RNA into DNA inside host cells?
Answer: Reverse transcriptase
Rationale: Reverse transcriptase allows retroviruses to integrate their genetic material into host cell DNA.
mRNA vaccines work by instructing cells to produce which viral component?
A viral antigen such as the spike protein
Rationale: The mRNA provides instructions for cells to produce a viral antigen that triggers an immune response.
Which laboratory marker is commonly used to detect systemic inflammation?
C‑reactive protein (CRP)
Rationale: CRP is produced by the liver during inflammatory processes and is often elevated during infection or inflammation.
Which autoimmune disease causes inflammation in multiple organs including skin, joints, and kidneys?
Systemic lupus erythematosus (SLE)
Rationale: SLE is caused by autoantibodies that attack normal tissues, leading to widespread inflammation.
Which cells directly destroy infected host cells?
Answer: Cytotoxic T cells (CD8+)
Rationale: Cytotoxic T cells recognize infected or abnormal cells and destroy them by releasing enzymes that cause cell death.
What serious complication of influenza can lead to hospitalization and respiratory failure?
Answer: Pneumonia
Rationale: Pneumonia is a major complication of influenza, especially in older adults or immunocompromised individuals.
What type of immunity occurs when antibodies are given through immunoglobulin injections?
Artificial passive immunity
Rationale: Artificial passive immunity occurs when antibodies are provided externally, giving immediate but temporary protection.
What procedure involves removing synovial fluid from a joint for analysis?
Arthrocentesis
Rationale: Arthrocentesis helps diagnose joint disorders such as infection, gout, or inflammatory arthritis.
Which autoimmune joint disease causes chronic inflammation and joint destruction?
Rheumatoid arthritis
Rationale: Rheumatoid arthritis is an autoimmune disease where the immune system attacks synovial joints.