A complex interacting system that protects the host from endogenous and exogenous microorganisms. It includes physical and chemical barriers, inflammatory response, reticuloendothelial system, and immune responses.
What is host defense mechanism?
PRINCIPLES OF HOST DEFENSES
Innate defenses can be classified into three major categories: (1) physical barriers, such as intact skin and mucous membranes; (2) phagocytic cells, such as neutrophils, macrophages, and natural killer cells; and (3) proteins, such as complement, lysozyme, and interferon.
What are examples of host defense mechanisms?
Host Defense Mechanisms Against Infection
- Natural barriers (eg, skin, mucous membranes)
- Nonspecific immune responses (eg, phagocytic cells [neutrophils, macrophages] and their products)
- Specific immune responses (eg, antibodies, lymphocytes)
What is the definition of defense mechanism in health?
Medical Definition of defense mechanism
1 : an often unconscious mental process (as repression, projection, or sublimation) that makes possible compromise solutions to personal problems. 2 : a defensive reaction by an organism.
What are the 3 defense mechanisms of the body?
The human body has three primary lines of defense to fight against foreign invaders, including viruses, bacteria, and fungi. The immune system’s three lines of defense include physical and chemical barriers, non-specific innate responses, and specific adaptive responses.
What is innate host defense?
Innate host defenses are mediated by cascades of constitutive proteins such as the complement system, and by cellular responses involving phagocytes (monocytes, macrophages, neutrophils) or natural killer (NK) cells.
How do interferons function as a host defense mechanism?
The Type I interferons are a group of related glycoproteins that play a key role in host defenses against viral infections. The interferons bind to a cell surface receptor and initiate the transcription of a wide range of proteins that have potent antiviral properties.
What is host defense failure?
This does not always happen, however, and in this chapter we will examine three circumstances in which there are failures of host defense against infection: avoidance or subversion of a normal immune response by the pathogen; inherited failures of defense because of gene defects; and the acquired immune deficiency …
What is non specific host Defence?
Nonspecific defenses include anatomic barriers, inhibitors, phagocytosis, fever, inflammation, and IFN. Specific defenses include antibody (more…) Although interferon was first recognized as an extraordinarily potent antiviral agent, it was found subsequently to affect other vital cell and body functions.
What is the 1st 2nd and 3rd line of defense?
The third line of defense provides assurance to senior management and the board that the first and second lines’ efforts are consistent with expectations. The main difference between this third line of defense and the first two lines is its high level of organizational independence and objectivity.
What are 4 defense mechanisms?
Here are a few common defense mechanisms:
Denial. Repression. Projection. Displacement.
What is altruism defense mechanism?
The defensive altruism, or ego-defensive altruism, refers to an altruistic act in which there is an unconscious self-serving motivation underneath the altruist’s conscious altruistic intention.
What are the 7 defense mechanisms?
Freudian defense mechanisms and empirical findings in modern social psychology: Reaction formation, projection, displacement, undoing, isolation, sublimation, and denial.
What are some biological defense mechanisms hosts have against infection?
Natural barriers include the skin, mucous membranes, tears, earwax, mucus, and stomach acid. Also, the normal flow of urine washes out microorganisms that enter the urinary tract.
What are the three defense mechanisms of the body describe them quizlet?
First line of defense, Skin and Mucus membrane; Second line of defense includes defensive cells, defensive proteins, inflammation, and fever; Third line of defense includes the immune system.
Which is the most important defense mechanism of the external immune system?
The body’s most important nonspecific defense is the skin, which acts as a physical barrier to keep pathogens out. Even openings in the skin (such as the mouth and eyes) are protected by saliva, mucus, and tears, which contain an enzyme that breaks down bacterial cell walls.