BIOD 331 Module 3|Questions & Answers|Updated Solution|Guaranteed A+ Score Guide

What is innate immunity? Your Answer: first line of defense, natural immunity, fast acting 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. Question 2 Not yet graded / O pts How does the skin act as a physical barrier? Your Answer: tightly packed cells prevent bacteria and other toxins from entering the body, the outer layers of cells are also keratinized which creates an acidic environment 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.Question Not yet graded / O pts 2/13 3 What cells are involved in innate immunity? Your Answer: neutrophils, dendritic cells, macrophages, lymphocytes, natural killer cells The cells responsible for this response include neutrophils, macrophages, dendritic cells (DC), natural killer (NK) cells, and intraepithelial lymphocytes. Question 4 Not yet graded / O pts Describe each type of leukocyte and explain their function: Your Answer: neutrophils: most abundant, early response, phagocytosis eosinophils: for parasites and allergic reactions basophils: release histamine & proteolytic enzymes monocytes: largest, from bone marrow, mature into macrophages & dendritic cells macrophages: long life span, first phagocytotic cells that toxins encounter 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. Question 5 Not yet graded / O pts Describe adaptive immunity: Your Answer: acquired immunity, second line of defense, humoral & cellular mechanisms, takes longer but it's very effective because of its specificity3/13 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. Question 6 Not yet graded / O pts What are antigens? Your Answer: foreign substance present on pathogen surface that illicit an adaptive immune response Antigens are present on the surface of pathogens or other foreign substances that elicit the adaptive immune response. Question 7 Not yet graded / O pts What are the primary cells of adaptive immunity? Your Answer: lymphocytes, antigen presenting cells, effector cells The primary cells of the adaptive immune system are the lymphocytes, APCs (antigen presenting cells), and effector cells. Question