Introduction to Basic Immunology

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