Quiz Over Chapter 16 Microbiology

Monocytes are a type of white blood cell that can migrate to infected areas. Once they reach the infected area, they undergo maturation and differentiate into two types of macrophages: fixed macrophages and wandering macrophages. Fixed macrophages are stationary and reside in specific tissues, while wandering macrophages move freely throughout the body. Therefore, the statement that monocytes mature into fixed macrophages and wandering macrophages as they migrate to infected areas is true.

The complement system is a group of 30+ proteins that work together in a cascade fashion to produce an amplified effect. These proteins increase the permeability of blood vessels, stimulate the movement of immune cells towards the site of infection (chemotaxis), cause the destruction of cells (cytolysis), and enhance the process of phagocytosis through opsonization. Therefore, the complement system plays a crucial role in the immune response against microbial pathogens.

Complement deficiencies can result in increased susceptibility to disease. The complement system is a part of the immune system that helps to fight off infections. When there is a deficiency in the complement system, the body's ability to fight off infections is compromised, making individuals more susceptible to diseases. Therefore, the statement that complement deficiencies cannot result in increased susceptibility to disease is false.

The statement suggests that host regulatory proteins play a role in inhibiting and breaking down the complement system. The complement system is a part of the immune system that helps in fighting infections. Therefore, if host regulatory proteins function as inhibitors and destructive enzymes, it would result in the inactivation of the complement system. Hence, the statement is true.

Interferons are antiviral proteins produced by host cells in response to viral infection. They come in three types: alpha, beta, and gamma. These proteins play a crucial role in the immune response against viruses by inhibiting viral replication and spreading to other cells. Interferons also enhance the activity of other immune cells, such as natural killer cells and macrophages, to help eliminate the virus. Overall, interferons are an important defense mechanism of the body against viral infections.

The correct answer includes various chemical factors that play a role in the body's defense against pathogens. Sebum is an oily substance secreted by the skin that helps create a barrier against bacteria. Perspiration contains antimicrobial peptides that can kill or inhibit the growth of bacteria. Lysozyme is an enzyme found in tears, saliva, and mucus that can break down bacterial cell walls. Gastric juice, which includes hydrochloric acid, can kill many bacteria that are ingested. Lactoferrin, peroxidase, complement, and interferons are all components of the immune system that help fight against pathogens in different ways.

The physical factors mentioned in the answer are all part of the body's defense mechanisms against pathogens. The skin acts as a barrier, preventing pathogens from entering the body. Mucous membranes, such as those in the respiratory and digestive systems, produce mucus that traps pathogens and prevents them from spreading. The lacrimal apparatus produces tears that contain enzymes and antibodies that can kill pathogens. Saliva contains antimicrobial enzymes that can help kill bacteria in the mouth. Hairs in the nose filter out particles and pathogens from the air we breathe. Urine flow helps to flush out any pathogens that may have entered the urinary system.

Transferrins are iron binding proteins found in various bodily fluids such as blood, milk, saliva, and tears. These proteins play a crucial role in reducing the amount of iron available to bacteria. By binding to iron, transferrins limit its availability to bacteria, which rely on iron for their growth and survival. This helps to inhibit bacterial growth and protect the body from infections.

The explanation for the given answer is that the normal flora, also known as microbiota, compete with potential pathogens for nutrients, produce harmful waste products, and alter the environment in ways that are unfavorable for the growth of pathogens. This competition and alteration of the environment contribute to innate immunity, which is the body's first line of defense against pathogens. Therefore, the statement "Normal flora compete for nutrients, produce wastes or metabolic products that are harmful, or alter environment (pH, oxygen levels, etc.) all of which help prevent growth of potential pathogens" refers to microbiota and innate immunity.

Phagocytosis refers to the process of a cell ingesting a microbe or particle. Cells that perform phagocytosis are known as phagocytes. This mechanism allows the cell to engulf and destroy foreign substances, such as bacteria or debris, in order to protect the body from infections and maintain tissue health. Phagocytes are an essential part of the immune system and play a crucial role in defending against pathogens.

The given answer, innate (non specific) immunity, refers to the body's natural defense mechanisms that protect against any invader. It is always present and responds rapidly without the need for prior exposure. It does not have a memory component, meaning it does not remember specific pathogens. Innate immunity includes two lines of defense: the adaptive immune response, which targets specific pathogens, and toll-like receptors, which recognize and respond to specific molecules associated with pathogens.