1. How do white blood cells remove dead tissues of the body? engulf them?
2. Do white blood cells respond to viral infections?
3. What cells can squeeze through the walls of the capillary wall?
4. Are holes present in the walls of capillaries?
5. What causes the surge in blood pressure in the artery of the arm of a person? the contraction of the left ventricle or the constriction of the aorta? why?