Final answer:
Bloodborne pathogens can enter the body via open cuts, skin abrasions, dermatitis, mucous membranes, or any breach in the skin's barrier, potentially leading to serious infections in the circulatory system.
Step-by-step explanation:
Bloodborne pathogens may enter the system through open cuts, skin abrasions, dermatitis, mucous membranes, and essentially, all of the above are correct. The skin and mucous membranes act as barriers to infectious agents. However, these barriers can be breached by various means, including punctures, abrasions, or large numbers of pathogens collecting on mucosal surfaces, which may overwhelm the body's defenses. Furthermore, pathogens can be introduced into the bloodstream through procedures such as the use of contaminated catheters, dental procedures, or wounds.
Infections of the circulatory system are significant given that the circulatory system is typically sterile. Any pathogens that enter the bloodstream must evade the body's immune defenses, which include antibodies, complement proteins, phagocytes, and other immune cells. For example, bacteria causing localized infections can spread to the bloodstream and throughout the body, leading to severe conditions such as septicemia and septic shock.