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In the first line of defense, inhaled bacteria are trapped by mucus and are swept toward the pharynx and are swallowed. [1] Bacteria which penetrate the mucous layer are dealt with a second line of defense which includes antimicrobial peptides that are secreted by the surface epithelium of the respiratory tract which kill many strains of ...
The second and third lines of defense operate by making changes to the buffers, each of which consists of two components: a weak acid and its conjugate base. [5] [13] It is the ratio concentration of the weak acid to its conjugate base that determines the pH of the solution. [14]
The mucosal immune system consists of a cellular component, humoral immunity, and defense mechanisms that prevent the invasion of microorganisms and harmful foreign substances into the body. These defense mechanisms can be divided into physical barriers ( epithelial lining , mucus , cilia function , intestinal peristalsis , etc.) and chemical ...
Animal models indicate that host defense peptides are crucial for both prevention and clearance of infection. It appears as though many peptides initially isolated as and termed "antimicrobial peptides" have been shown to have more significant alternative functions in vivo (e.g. hepcidin [18]). Dusquetide for example is an immunomodulator that ...
Biological defense may refer to: Biological defense mechanism, a form of adaptation that promotes the survivability of an organism by protecting it from its natural enemies, such as predators ( Anti-predator adaptation ) or pathogens ( Immune system )
Complement proteins are proteins that play a role in the non-specific immune responses alongside these non-specific immune cells to make up the first line of immune defense. [4] The non-specific immune response is an immediate antigen-independent response, however it is not antigen-specific. Non-specific immunity results in no immunologic memory.
Chemical defense is a strategy employed by many organisms to avoid consumption by producing toxic or repellent metabolites or chemical warnings which incite defensive behavioral changes. [ 1 ] [ 2 ] The production of defensive chemicals occurs in plants, fungi, and bacteria, as well as invertebrate and vertebrate animals.
An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellular bacteria, protozoa, helminths, and fungi which could cause serious problems to the health of the host organism if not cleared from the body.