nonspecific host defense mechanisms
are general and serve to protect the body against many harmful substances
nonspecific host defense mechanisms
it is also called as innate immunity
skin and mucous membrane
it serves as a physical or mechanical barrier to pathogens
perspiration
a nonspecific host defense mechanism that flushes organisms from spores and the surface of the skin which also contains lysozyme that degrades peptidoglycan in walls
microbial antagonism
refers to resident microbes of the indigenous microbiota prevent colonization by new arrivals to a particular anatomical site
lysozyme
destroys bacterial cell wall by degrading peptidoglycan
lactoperoxidase
an enzyme that produce superoxidase radicals, which are highly reactive forms of oxygen, which are toxic to bacteria
superinfection
refers to the overgrowth of bacteria or fungi that are resistant to the antibiotics being administered
transferrin
a glycoprotein synthesized in the liver and has high affinity for iron which function is to store and deliver iron to host cells and deprive pathogens of iron
pyrogens or pyrogenic substances
substances that stimulates production of fever
interferons
are small, antiviral proteins produced by virus-infected cells and they interfere with viral replication
alpha interferons, beta interferons, and gamma interferons
what are the three known types of interferons?
alpha interferons
a type of interferon produced by B lymphocytes, monocytes, and macrophages
beta interferons
a type of interferon produced by fibroblasts and other virus-infected cells
gamma interferons
a type of interferon that is activated by T lymphocytes (T cells) and natural killer cells (NK cells)
the complementary system or complement
it completes or enhances cells of the immune system in destroying microbes and it consists of over 30 proteins produced by the liver that circulate in blood serum and within tissues throughout the body
opsonization
a process by which phagocytosis is facilitated by the deposition of opsonins
acute plasma proteins
refers to the plasma levels of molecules that increase rapidly in response to infection, inflammation, and tissue injury. it also enhances resistance to infection and promoting the repair of damaged tissue
cytokines
are chemical mediators that are released from many different types of cells which enable cells to communicate with each other and act as chemical messengers
inflammation
refers to a complex series of events which is a response of the body to any local injury, irritation, microbial invasion, or bacterial toxin
redness, heat, swelling (edema), and pain
what are the four cardinal signs and symptoms of inflammation?
inflammatory exudate
refers to the accumulation of fluid, cells, and cellular debris at the inflammation site
purulent pus or pus
a thick and greenish exudate that contains many live and dead leukocytes
phagocytosis
the process by which phagocytes surround and engulf foreign material
macrophages and neutrophils
what are the two most important groups of phagocytes in the human body?
macrophages
it serves as a cleanup crew to the body of unwanted and harmful substances, such as dead cells, unused cellular secretions, debris, and microbes
monocytes, lymphocytes, and granulocytes
what are the three major categories of leukocytes found in the blood?
neutrophils, basophils, and eosinophils
what are the three types of granulocytes?
neutrophils
it is also known as polymorphonuclear cells, polys and PMNS that are much more efficient at phagocytosis than eosinophils
eosinophilia
refers to an abnormally high number of eosinophils in the peripheral bloodstream
basophils
a type of granulocyte that are involved in allergic and inflammatory reactions and contains histamine and other chemical mediators
wandering macrophages
a macrophage that leave the bloodstream and migrate to infected areas
fixed macrophages
macrophage that remain within tissues and organs and serve to trap foreign debris
reticuloendothelial system (RES)
its principal function is the engulfment and removal of foreign and useless particles, living or dead, as well as foreign debris and microbes that gain entrance to the body
chemotaxis, attachment, ingestion, and digestion
what are the four steps in phagocytosis?
chemotaxis
a step in phagocytosis where phagocytes are attached by chemotactic agents to the elite site where they are needed
attachment
a step in phagocytosis where a phagocytic attaches to an object
ingestion
a step in phagocytosis where pseudopods surround the object and is taken into the cell
digestion
a step in phagocytosis where the object is broken down and dissolved by digestive enzymes and other mechanisms
immune system
it is considered to be the third line of defense that springs into action to defend against specific pathogen that has gained entrance to the body