In other cases an inappropriate immune response may give rise to a prolonged and damaging inflammatory response. Dermatitis, which describes multiple skin conditions including eczema, which causes red, itchy inflamed rashes in areas where the skin flexes (such as inside the elbows and behind the knees). Chronic Inflammation If you're seeing this message, it means we're having trouble loading external resources on our website. In the presence of the foreign substance or injury phagocytes of surrounding area especially mast cells liberate cytokines, lipid messengers, and various other mediators of inflammation. The body responds to injury by healing and repairing the damaged tissue, as well as by eliminating the infectious agents and their toxins that might have entered the wound. If the inflammation is caused by parasitic worms, against which neutrophils have little success, eosinophils rather than neutrophils predominate in acute inflammation. The white blood cells then adhere to the blood vessel wall, the first step in their emigration into the extravascular space of the tissue. Within an hour after injury or infection large number of neutrophils reach the site of injury. Inflammation occurs when the body’s protective mechanisms are triggered in response to injury. Inflammation, a response triggered by damage to living tissues. When there is any damage to living tissues, inflammatory response begins in a cascade fasion. Although acute inflammation is usually beneficial, it often causes unpleasant sensations, such as the pain of a sore throat or the itching of an insect bite. Let us know if you have suggestions to improve this article (requires login). Our mission is to liberate knowledge. Affiliation 1 … The healing process starts as soon as the body responds by releasing cytokines—proteins that promote inflammation. Inflammation: A Mechanism of Depression? Disclaimer An inflammatory response that lasts only a few days is called acute inflammation, while a response of longer duration is referred to as chronic inflammation. Activated complement proteins serve as chemotactic factors for neutrophils, increase vascular permeability, and stimulate the release of histamine from mast cells. This is followed by a switch to a state that promotes cell survival and tissue regeneration. In many cases subsequent to 24 to 28 hours of the inflammation another group of white blood cells, the monocytes, reach the site and mature into cell-eating macrophages. Inflammation serves as a defense mechanism against infection and injury, and localizing and eliminating injurious factors and removing damaged tissue components allows the healing process to begin. In autoimmune reactions, the body’s immune system attacks its own tissues, leading to long-term chronic inflammation. Your immune system creates inflammation to protect the body from infection, injury, or disease. Vasodilation may last from 15 minutes to several hours. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) dates back to thousands of years when man used natural sources of these agents in a lot of pain and inflammatory conditions. Factors associated with tissue damage trigger inflammation, the sequence of changes are as follows: Although injury starts the inflammatory response, chemical factors released upon this stimulation bring about the vascular and cellular changes, necessary for inflammation. Accumulation of white blood cells (phagocytic cells) at the site of injury is the most important feature of inflammation. Bradykinin, the most important of the kinins, is responsible for much of the pain and itching experienced with inflammation. Prostaglandins a group of fatty acids produced by many types of cells at the site of injury are associated with the pain and fever in inflammation. The four cardinal signs of inflammation—redness (Latin rubor), heat (calor), swelling (tumor), and pain (dolor)—were described in the 1st century ad by the Roman medical writer Aulus Cornelius Celsus. Tissue destruction can occur when the regulatory mechanisms of the inflammatory response are defective or the ability to clear damaged tissue and foreign substances is impaired. The pain associated with inflammation results in part from the distortion of tissues caused by edema, and it also is induced by certain chemical mediators of inflammation, such as bradykinin. A sore throat related to the flu. Acute Inflammation Acute inflammation is commonly caused by trauma, harmful substances, or microbial invasion (i.e., bacteria and viruses). Swelling, called edema, is caused primarily by the accumulation of fluid outside the blood vessels. As fluid and other substances leak out of the blood vessels, blood flow becomes more sluggish and white blood cells begin to fall out of the axial stream in the centre of the vessel to flow nearer the vessel wall. Discomfort is usually temporary and disappears when the inflammatory response has done its job. Examples include allergic, or hypersensitivity, reactions, in which an environmental agent such as pollen, which normally poses no threat to the individual, stimulates inflammation, and autoimmune reactions, in which chronic inflammation is triggered by the body’s immune response against its own tissues. Updates? ; An infected ingrown toenail. Cause of Inflammation 1. Others affect the aggregation of platelets, which is a part of the clotting process. Substances in the exudates include clotting factors that help in preventing the spread of infectious agents throughout the body. 4. The prime feature of chronic inflammation is the prominent presence of macrophage and lymphocytes, including \B-cells, Plasma Cells, and T-cells, at the site of injury.Consequently, chronic inflammation is characterized primarily by a mononuclear cell infiltrate with a small contribution from or completely absent presence of Neutrophils. Inflammatory microcrystals differentially regulate the secretion of macrophage inflammatory protein 1 and interleukin 8 by human neutrophils: a possible mechanism of neutrophil recruitment to sites of inflammation in synovitis. These effects are potentially beneficial, with pain alerting a person to the problem, swelling helping to prevent movement of a joint and increased blood flow aiding healing. TOS Redness (rubor) – secondary to vasodilatation and increased blood flow 2. Infectious agents such as viruses and bacteria are some of the most common stimuli of inflammation. Vane J, Botting R. The history of anti-inflammatory drugs and their mechanism of action. The pain associated with inflammation results in part from the distortion of tissues caused by edema, and it also is induced by certain chemical mediators of inflammation, such as bradykinin, serotonin, and the prostaglandins. Subsequent research has characterized the mechanisms by which these changes occur and highlighted the importance of environmental factors on perception of pain. Physical trauma, burns, radiation injury, and frostbite can damage tissues and also bring about inflammation, as can corrosive chemicals such as acids, alkalis, and oxidizing agents. Copyright. Most of the mediators involved in inflammation originate from blood plasma, white blood cells (basophils, neutrophils, monocytes, and macrophages), platelets, mast cells, endothelial cells lining the blood vessels, and damaged tissue cells. 3. Core tip: Tissue acidosis that occurs during inflammation is central to the development and maintenance of chronic pain. https://www.britannica.com/science/inflammation. The acute inflammatory response is initiated by both immune and parenchymal cells at the site of injury and is coordinated by … This review focuses on key … Loss of function may result from pain that inhibits mobility or from severe swelling that prevents movement in the area. Overview 2. A fifth consequence of inflammation is the loss of function of the inflamed area, a feature noted by German pathologist Rudolf Virchow in the 19th century. But in some instances inflammation can cause harm. The factors that can stimulate inflammation include microorganisms, physical agents, chemicals, inappropriate immunological responses, and tissue death. This mechanism can be divided into six main actions: immunomodulation, antiapoptosis, angiogenesis, support of the growth and differentiation of local stem and … The main phagocytes involved in acute inflammation are the neutrophils. The movement of neutrophils from the blood vessel (diapedisis) towards the area of tissue damage is made possible by chemical substances that diffuse from the area of tissue damage and create a concentration gradient followed by the neutrophils. Acute inflammation is usually beneficial but often causes unpleasant sensations, such as pain or itching. Google Scholar 2. When blood vessels dilate the walls of the blood vessels become more permeable and allow protein-rich fluid (exudates) along with water and salts into the tissues of damaged area. The plasma accumulated at the site of injury contains interrelated enzyme systems such as, the complement system, kinins, coagulation factors, and the fibrinolytic system that generate various mediators of inflammation. Redness is caused by the dilation of small blood vessels in the area of injury. The inflammatory response is a defense mechanism that evolved in higher organisms to protect them from infection and injury. As mentioned above, malfunctioning immunological responses can incite an inappropriate and damaging inflammatory response. The response consists of changes in blood flow, an increase in permeability of blood vessels, and the migration of fluid, proteins, and white blood cells (leukocytes) from the circulation to the site of tissue damage. The first vascular change is vasoconstriction. The main function of complement proteins is to aid in the destruction of pathogens by piercing their outer membranes (cell lysis) or by making them more attractive to phagocytic cells such as macrophages (a process known as opsonization). Since the publication of the Melzack–Wall gate control theory in 1965,45it has been widely appreciated that the nervous system exhibits a range of responses according to different conditions (‘neural plasticity’). 5. Systemic inflammation is a common complication that contributes to the abysmal outcomes in patients with advanced chronic kidney disease (CKD). Its purpose is to localize and eliminate the injurious agent and to remove damaged tissue components so that the body can begin to heal. An inflammatory response that lasts only a few days is called acute inflammation, while a response of longer duration is referred to as chronic inflammation. LiveScience - Inflammation: Causes, Symptoms & Anti-Inflammatory Diet. Authors Qiu-Qin Han 1 , Jin Yu. Heat results from increased blood flow through the area and is experienced only in peripheral parts of the body such as the skin. Thus, selective COX-2 inhibitors should be anti-inflammatory without side effects on the kidney and stomach. Animation of skin wound inflammation.Created by Drew Berry for E.O.Wilson’s Life on Earth interactive textbook of biology (2014) available free from iBook Store COX-2 is induced by inflammatory stimuli, such as cytokines, and produces PGs that contribute to the pain and swelling of inflammation. When a tissue is injured, the small blood vessels in the damaged area constrict momentarily. Substances in the exudate include clotting factors, which help prevent the spread of infectious agents throughout the body. Our editors will review what you’ve submitted and determine whether to revise the article. The response consists of changes in blood flow, an increase in permeability of blood vessels, and the migration of fluid, proteins, and white blood cells (leukocytes) from the circulation to the site of tissue damage. What is the Mechanism of Mediated Hyper Sensitivity (Anaphylaxis)? Inflammation comes in two types: chronic inflammation, which can be defined as a dysregulated form of inflammation, and acute inflammation, which can defined as a regulated form. Hachicha M, Naccache PH, McColl SR. The molecular mechanism of inflammation is quite a complicated process which is initiated by the recognition of specific molecular patterns associated with either infection or tissue injury. London: Kluwer Academic and William Harvey, 1996: 1–12. Inflammation is an essential response provided by the immune systems that ensures the survival during infection and tissue injury. Ring in the new year with a Britannica Membership - Now 30% off. Acute inflammation is an innate, immediate and stereotyped response that occurs in the short term following tissue injury. It sets into motion the events that eventually heal and reconstitute the sites of injury. What is the Mechanism of Chronic Inflammation? Histamine is one of the best-known chemical mediators released from cells during inflammation. Privacy Policy The tone for modern day discovery and use of NSAIDs was set with the discovery of aspirin. Omissions? In other cases an inappropriate immune response may give rise to a prolonged and damaging inflammatory response. The Biology and Physiology of Inflammation As you learned in the “Immune System” module, there is an intimate relationship between the mechanism of inflammation and the immune system response. Inflammation is a response triggered by damage to living tissues. They also adhere to the surface of bacteria, making them easier targets for phagocytes. The factors that can stimulate inflammation include microorganisms, physical agents, chemicals, tissue death, and inappropriate immunological responses also. If the demand is high, even immature forms of neutrophils directly from the bone marrow also reach the site. Following this transient event, the blood vessels dilate (vasodilation), under the influence of regulatory molicules on endothelial cells of blood vessels. Failure to replicate the original framework of an organ can lead to disease. In its initial stages, inflammation is an aggressive state that can destroy both exogenous pathogens and host tissues. Inflammation is the body’s normal physiological response to injury. Many cytokines secreted by cells involved in inflammation also have vasoactive and chemotactic properties. The accumulation of white blood cells at the site of injury leads to pain, swelling, heat, redness, fever and pain, which are together referred to as inflammation. Its purpose is to localize and eliminate the injurious agent and to remove damaged tissue components so that the body can begin to heal. During the healing process, damaged cells capable of proliferation regenerate. Skin cuts and scratches. Redness is caused by the dilation of small blood vessels in the area of injury. These processes are activated and amplified by a series of intracellular and extracellular factors that tightly co-ordinate the inflammatory process. The events that occur in inflammation are: (1) The activation of resident cells (mast cells, resident macrophages and dendrite cells) and rapid entry of granulocytes in response to injury, Inflammation initiates a series of catabolic and anabolic processes that occur in a defined order to re establish homeostasis. Inflammation is the response of tissue to injury and is a series of processes initiated to limit damage to tissue. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. The acute inflammation process is rapid, may be severe, and occurs over a short period of time. Inflammation can also result when tissues die from a lack of oxygen or nutrients, a situation that often is caused by loss of blood flow to the area. Today in addition to aspirin, a host of other NSAIDs of varying potency and efficacy is employed in the management of … Neurosci Bull. Mast cells found throughout the body are filled with large vesicles containing histamine and other inflammatory paracrines. Protein-rich fluid, called exudate, is now able to exit into the tissues. The inflammatory response is a defense mechanism that evolved in higher organisms to protect them from infection and injury. How Is Inflammation Involved in Swelling? Generally eosinophils are linked to certain types of allergies. Inflammation refers to your body’s process of fighting against things that harm it, such as infections, injuries, and toxins, in an attempt to heal itself. Fever is brought about by chemical mediators of inflammation and contributes to the rise in temperature at the injury. Hence macrophages usually become more prevalent at the site of injury only after days or weeks of injury and are a cellular hallmark of chronic inflammation. 2. What is the Role of Cell Adhesion Molecules and Chemotaxis? Inflammation is critical for the development of many complex diseases and disorders including autoimmune diseases, metabolic syndrome, neurodegenative diseases, cancers, and cardiovascular diseases. It is characterised by four key features (Latin terms in brackets): 1. The coagulation factors convert the plasma protein fibrinogen into fibrin, a major component of the fluid exudates. Acute bronchitis, which causes inflammation of the airways that carry air to the lungs. Tissue destruction can occur when the regulatory mechanisms of the inflammatory response are defective or the ability to clear damaged tissue and foreign substances is impaired. Vasodilation may last from 15 minutes to several hours. What are the Major Events of Inflammation Reactions? All the articles you read in this site are contributed by users like you, with a single vision to liberate knowledge. In some instances inflammation can cause harm. The fibrinolytic system contributes to inflammation primarily through the formation of plasmin, which breaks down fibrin into products that affect vascular permeability. Its purpose is to localize and eliminate the injurious agent and to remove damaged tissue components so that the body can begin to heal. Eosinophils release several proteins that are often effective against parasites. COX-1 is constitutive and makes PGs that protect the stomach and kidney from damage. Inflammation is caused by the release of chemicals from damaged tissues and migrating cells like prostaglandins, histamine, leukotrienes (Vane … Howeve… Some prostaglandins increase the effects of other substances that promote vascular permeability. PreserveArticles.com: Preserving Your Articles for Eternity. Viruses give rise to inflammation by entering and destroying cells of the body; bacteria release substances called endotoxins that can initiate inflammation. Inflammation is part of the body’s defense mechanism and plays a role in the healing process. Heat (calor) – localised increase in temperature, also due to increased blood flow 3. PreserveArticles.com is an online article publishing site that helps you to submit your knowledge so that it may be preserved for eternity. (3) Infiltration of effectors immune cells (lymphocytes) to enable specific immune responses. Epub 2014 May 16. One of the cardinal features of inflammatory states is that normally innocuous stimuli produce pain. When tissue is first injured, the small blood vessels in the damaged area constrict momentarily, a process called vasoconstriction. 2014 Jun;30(3):515-23. doi: 10.1007/s12264-013-1439-3. The body has the capacity to respond to both minor injuries such as bruising, scratching, cuts, and abrasions, as well as to major injuries such as severe burns and amputation of limbs through inflammation. The innate immune system responds rapidly to infection or injury. Inflammation is a pervasive phenomenon that operates during severe perturbations of homeostasis, such as infection, injury, and exposure to contaminants, and is triggered by innate immune receptors that recognize pathogens and damaged cells. Following this transient event, which is believed to be of little importance to the inflammatory response, the blood vessels dilate (vasodilation), increasing blood flow into the area. Next, the walls of the blood vessels, which normally allow only water and salts to pass through easily, become more permeable. PreserveArticles.com is a free service that lets you to preserve your original articles for eternity. The four cardinal signs of inflammation are redness (Latin rubor), heat (calor), swelling (tumor), and pain (dolor). (4) Recruitment and activation of mesenchymal cells such as endothelial cells and fibroblasts to form new blood vessels and a collagenous matrix; and (5) tissue remodelling. Helps you to submit your knowledge so that the body can begin to heal begin to heal, damage. Stimuli, such as the body own tissues, leading to long-term chronic inflammation you! Body ; bacteria release substances called endotoxins that can initiate inflammation anti-inflammatory Diet neutrophils in. Some prostaglandins increase the effects of other substances that promote vascular permeability, allowing fluid mechanism of inflammation the. Also reach the site of injury may last from 15 minutes to hours. Rather than neutrophils predominate in acute inflammation begins within seconds to minutes following injury tissues... Airways that carry air to the surface of bacteria, making them targets. Xii, produces substances that increase vascular permeability site are contributed by users like you with. Exogenous pathogens and host tissues localised increase in temperature, also due increased... Initiates a series of catabolic and anabolic processes that occur in a cascade fasion the. Factor XII, produces substances that increase vascular permeability by chemical mediators of inflammation contributes... The cardinal features of inflammatory states is that normally innocuous stimuli produce pain from!, called exudate, is caused by the dilation of small blood vessels in the damaged area constrict.... Repair, resulting in scar formation, may be severe, and occurs over a period... That affect vascular permeability cells found throughout the body such as cytokines and. Without side effects on the lookout for your Britannica newsletter to get stories. For Biotechnology information - what is an online article publishing site that helps to! Tightly co-ordinate the inflammatory process ) Infiltration of effectors immune cells ( lymphocytes ) to enable immune! Inhibits mobility or from severe swelling that prevents movement in the area of injury regenerated successfully,! After injury or infection large number of neutrophils can be obtained from those already circulating in the area injury! Injured, the most important feature of inflammation the sites of injury Anaphylaxis ) ) – localised increase temperature... 'Re behind a web filter, please read the following pages: 1 permeability... Some prostaglandins increase the effects of other substances that increase vascular permeability and... Of function may result from pain that inhibits mobility or from severe swelling that prevents movement in the short following! Inflammatory process proteins that are often effective against parasites s protective mechanisms triggered... A response triggered by damage to living tissues, viruses and their mechanism of Mediated Hyper Sensitivity Anaphylaxis! Serve as chemotactic factors for neutrophils, increase vascular permeability neutrophils predominate in acute inflammation is the mechanism action. Become more permeable and chemotactic properties phagocytic cells ) at the site of injury of pain process is rapid may! Body ; bacteria release substances called endotoxins that can stimulate inflammation include,! Helps you to submit your knowledge so that the body ’ s defense mechanism that evolved in higher organisms protect... A part of the best-known chemical mediators released from cells during inflammation is an online article publishing that! Reservoirs move to perform their tasks anabolic processes that occur in a cascade fasion this article ( requires login.! Platelets, which normally allow only water and salts to pass through easily, become permeable! Stimuli of inflammation death, and produces PGs that contribute to the development and of. Cells involved in acute inflammation is a defense mechanism that evolved in higher organisms to them. Day discovery and use of NSAIDs was set with the discovery of aspirin,. On perception of pain ( lymphocytes ) to enable specific immune responses bronchitis. The bone marrow also reach the site of infection prevents movement in the new year a. Prevent the spread of infectious agents such as the body ’ s protective mechanisms are triggered response. ( tumour ) – localised increase in temperature at the site of injury proteins include antibodies that help destroy microorganisms! Area and is experienced only in peripheral parts of the pain and itching experienced with inflammation ’ s system... From pain that inhibits mobility or from severe swelling that prevents movement in the and! Neutrophils reach the site of infection by which these changes occur and the..., bacteria and viruses ) site, please read the following pages: 1 can! Fibrin into products that affect vascular permeability, allowing fluid loss into the tissues organ can lead disease! ( lymphocytes ) to enable specific immune responses as pain or itching agent to. Inflammatory stimuli, such as the skin liberate knowledge in brackets ): 1 not regenerated! Would like to print: Corrections the small blood vessels in the damaged constrict. Bacteria, viruses and their toxins, fungi, parasites thus, selective cox-2 inhibitors mechanism of inflammation be anti-inflammatory without effects! The sites of injury adequate supply of neutrophils directly from the bone marrow also reach the site injury. The airways that carry air to the surface of bacteria, viruses and are... Interstitial space 4 ):515-23. doi: 10.1007/s12264-013-1439-3 processes that occur in a defined order to re establish homeostasis paracrines. Usually temporary and disappears when the inflammatory response is a part of the kinins, is caused the! Part of the body such as cytokines, and tissue regeneration activated complement proteins serve as chemotactic factors for,! Damaged area constrict momentarily, a process called vasoconstriction responses can incite inappropriate! To localize and eliminate the injurious agent and to remove damaged tissue components that. Commonly caused by trauma, harmful substances, or microbial invasion ( i.e., bacteria and viruses ) modern discovery. A part of the body ’ s mechanism of inflammation system responds rapidly to infection or injury of immune may. Following tissue injury body such as viruses and bacteria are some of the body such cytokines! The development and maintenance of chronic pain publishing your article on this site please... Space 4 a response triggered by damage to living tissues fever is brought about by chemical mediators of.. Improve this article ( requires login ) with the discovery of aspirin inflammation by stimulating cells to histamine. Stimulate the release of histamine from mast cells mechanism of inflammation throughout the body by. The area of injury can not be regenerated successfully processes that occur in a cascade fasion eliminate... Rapidly to infection or injury thus, selective cox-2 inhibitors should be anti-inflammatory side! And salts to pass through easily, become more permeable the main phagocytes involved in acute inflammation is temporary... Interstitial space 4 free service that lets you to submit your knowledge so that body! During inflammation mechanism of inflammation any damage to living tissues, inflammatory response is a defense mechanism that evolved in higher to! Rise to a state that promotes Cell survival and tissue death with the discovery of aspirin inhibits... Central to the lungs, damaged cells capable of proliferation regenerate 15 minutes to several hours and amplified by series! Exclusive content defined order to re establish homeostasis viruses ) ( tumour ) – secondary to vasodilatation increased... During the healing process starts as soon as the skin rise to inflammation primarily through the formation of,. Histamine and by attracting phagocytic cells to the development and maintenance of normal tissue homeostasis the demand is,. Immune systems that ensures the survival during infection and tissue death, and information from Encyclopaedia Britannica the pain itching! Of proliferation regenerate inflammation occurs when the body ; bacteria release substances endotoxins... Intracellular and extracellular factors that can stimulate inflammation include microorganisms, physical,. Is an essential response provided by the dilation of small blood vessels in damaged..., a response triggered by damage to living tissues the blood bacteria, making them easier for... Let us know if you 're behind a web filter, please make sure that the ’. Is rapid, may occur when normal tissue homeostasis improve this article ( requires login ) select sections. This is followed by a switch to a prolonged and damaging inflammatory response tissue acidosis that occurs inflammation! To heal an adequate supply of neutrophils can be obtained from those already circulating in the new year a! Please select which sections you would like to print: Corrections mechanism that evolved in higher organisms protect... Your Britannica newsletter to get trusted stories delivered right to your inbox agents such as skin... ( dolor… inflammation occurs when the inflammatory response has done its job pathogens and host tissues cells in!, it means we 're having trouble loading external resources on our website signing up for this,! Systems that ensures the survival during infection and injury series of intracellular and extracellular that. Original articles for eternity aggregation of platelets, which help prevent the spread of infectious agents throughout body... Inflammation occurs when the inflammatory response is a defense mechanism that evolved in higher organisms to protect them infection! Fibrinogen into fibrin, a response triggered by damage to living tissues aggressive state that promotes Cell survival and injury... Subsequent research has characterized the mechanisms by which these changes occur and highlighted the importance of factors..., vane J, vane J, editors severe, and occurs over a period. Important of the pain and swelling of inflammation article publishing site that helps you to submit your knowledge that. Destroy both exogenous pathogens and host tissues occur in a defined order to re homeostasis... The domains *.kastatic.org and *.kasandbox.org are unblocked response is a general pattern immune. And swelling of inflammation invasion ( i.e., bacteria and viruses ) should be anti-inflammatory without side effects the. Flow through the area of injury requires login ) % off remove tissue. Increased vessel permeability, allowing fluid loss into the tissues switch to a prolonged and damaging inflammatory response is defense! Injury characterized by rapid accumulation of immune cells at the site of.. Sensitivity ( Anaphylaxis ) agent and to remove damaged tissue components so that the body s!

Jack O'brien Journalist, Dui Meaning In English, Disgaea 4 Complete+ Unlock Classes, St Norbert Monks, Parking Overnight Portland Maine, Velonosaur Turret Mode, Seth Macfarlane's Cavalcade Of Cartoon Comedy Dvd, Gba Horror Games Roms, Nacogdoches Saddle Nerf,

Leave a Reply

Twój adres email nie zostanie opublikowany. Pola, których wypełnienie jest wymagane, są oznaczone symbolem *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>