Explanation: The second line of defense is the inflammatory response. Inflammation is a local response to cellular injury or infection that includes capillary dilation and leukocyte infiltration. Normal flora is the body's first line of defense. The immune response is the body's attempt to protect itself from foreign and harmful substances. Humoral immunity is a defense system that involves white blood cells (B lymphocytes) that produce antibodies in response to antigens or pathogens circulating in the lymph and blood.
Explanation: Contact precautions are used when a known or suspected contagious disease may be present and is transmitted through direct contact with the patient or indirect contact with items in the patient's environment. Airborne precautions are used when known or suspected contagious diseases can be transmitted by means of small droplets or particles that can remain suspended in the air for prolonged periods. Droplet precautions are used when known or suspected contagious diseases can be transmitted through large droplets suspended in the air. Protective isolation is used for patients who have compromised immune systems.
Explanation: Vectors carry pathogens from one host to another. Bacteria are single-cell organisms. Viruses are the smallest organisms. Fungi are single-cell organisms that can cause infection.