NURS 231 Pathophysiology Exam 3 Questions With Verified Answers

NURS 231 Pathophysiology Exam 3 Questions With Verified Answers innate immunity Innate immunity, also called natural immunity, is the first line of defense. This type of defense is in place before an infection takes place and can function immediately. It is comprised of physical, chemical, cellular, and molecular defenses. How does the skin act as a physical barrier? The skin's design makes it a strong physical barrier. It has closely packed cells in multiple layers that are continuously being shed. Keratin covers the skin, which creates a salty, acidic environment inhospitable to microbes. It also contains antimicrobial proteins and lysozymes that inhibit microorganisms and help to destroy them. What cells are involved in innate immunity? neutrophils macrophages dendritic cells (DC) natural killer (NK) cells intraepithelial lymphocytes Describe each type of leukocyte and explain their function. Neutrophils are the most abundant in the body and are an early responder in innate immunity and use phagocytosis to kill microbes. Eosinophils are active in parasitic infections and allergic responses. Basophils release histamine and proteolytic enzymes. Monocytes are the largest in size and are released from the bone marrow and mature into macrophages and dendritic cells where they engage in the inflammatory response and phagocytize foreign substances and cellular debris. Macrophages have a long life span, reside in the tissues, and are the first phagocyte that organisms encounter. Neutrophils and macrophages work together on behalf of the host's initial defense system. adaptive immunity Adaptive immunity, also called acquired immunity, is the second line of defense and includes both humoral and cellular mechanisms that respond to cell-specific substances known as antigens. Adaptive immunity is acquired through previous exposure to infections and other foreign agents. It can not only distinguish self from nonself but can recognize and destroy specific foreign agents based on their different antigenic properties. This response takes more time but is extremely effective. antigens Antigens are present on the surface of pathogens or other foreign substances that elicit the adaptive immune response. What are the primary cells of adaptive immunity? The primary cells of the adaptive immune system are the lymphocytes, APCs (antigen presenting cells), and effector cells. Describe B & T lymphocytes and discuss their role in immunity: