All MCQs

Pulmonary circulation moves blood from the heart to the lungs and back. Systemic circulation moves blood between the heart and body tissues.

After feeding, the digestive tract requires increased blood supply for absorption, transport, and metabolic processing of nutrients.

Blood distribution changes with activity, digestion, temperature, and stress. Regulation ensures active tissues receive enough oxygen and nutrients.

Vaccination initiates adaptive immune responses. Lymphocyte activation, antibody production, and memory formation take time.

Allergy results from inappropriate or exaggerated immune responses to harmless substances such as pollen, foods, or dust.

Tissue injury triggers inflammatory responses that recruit immune cells and defensive molecules to contain pathogens and begin repair.

Complement proteins are part of innate immunity and can opsonize microbes, promote inflammation, and form membrane attack complexes.

Innate defenses include antimicrobial molecules such as lysozyme and defensins. They act broadly against microbial structures.

Lymph flows under low pressure and depends on muscle movement and valves. Valves prevent backflow and support return to the bloodstream.

Lymph is derived from interstitial fluid and usually contains fewer proteins and lacks red blood cells. It contains lymphocytes and other immune components.

Lymph nodes filter lymph and contain immune cells. Swelling often reflects immune activation during infection.

Invertebrate clotting responses help seal wounds and trap pathogens. This is part of innate defense and fluid balance.