Final answer:
In response to distilled water being injected into a blood vessel, red blood cells will swell and potentially burst in a process called hemolysis due to water rushing into the cells by osmosis.
Step-by-step explanation:
When distilled water is injected into a blood vessel, the red blood cells surrounded by the water would undergo a process called hemolysis. This occurs because the distilled water is a hypotonic solution, meaning it has a lower concentration of solutes compared to the solutes present inside the red blood cells. As a result, water rushes into the cells due to osmosis, causing them to swell. Since the red blood cell membrane has a fixed surface area, as the cells take in more water, they increase in size until they eventually burst since they lack the mechanisms to prevent the excessive intake of water, unlike most other cells.