CNA Practice Test
Body systemsQuestion 791 of 1700

Which are nonspecific defenses that block pathogens from entering?

  1. The skin and mucous membranes
  2. White blood cells in the blood
  3. The heart and blood vessels
  4. The kidneys and bladder
Show answer

Correct answer: The skin and mucous membranes

These parts act as barriers.

Source: Nursing Assistant (Reuter), 11.9: Immune System

Practice body systems

Questions last reviewed: 18 October 2026