What are the body's responses to injury?
An alteration in the environment that causes tissue damage or necrosis.
The pathologic death of one or more cells or a part of tissue, or an organ that results from irreversible damage to cells.
Removal of foreign substances
Flushing action of tears, saliva, urine, and diarrhea
Enzymes in saliva and tears
Respiratory system’s cilia and mucus
____injury can affect teeth, soft tissue and bone.
___ injury can occur from the application of caustic substances.
____ can cause injury by invading orofacial tissue and causing infections.
_____ can render orofacial tissue more susceptible to injury from other sources, and toxic overdoses of some nutrients can also cause tissue damage.
are present from birth and include intact skin or mucosa that acts as a physical barrier to injury. The process of inflammation an its white blood cells that are brought to the area of injury are innate responses to injury.
clinical signs (cardinal signs) of inflammation include: localized
redness, heat, swelling, pain and loss of the usual level of tissue function
- suffix -itis
- Allows the body to eliminate injurious agents, contain injuries, and heal defects
- A nonspecific response to injury that involves the microcirculation and its blood cells.
- Extent and duration of the injury determine the extent and duration of inflammatory response.
- local or systemic
- acute or chronic
A disease process that is confined to a limited location in the body that is not general or systemic
- Pertaining to or affecting the body as a whole, as well as a disease process pertaining to or affecting the body as a whole.
- Elevated C-reactive protein (CRP)
An injury or course of inflammation that is of sort duration.
- An injury or course of inflammation that is of long duration.
- Caused by persistent injuries
- Repair cannot be completed until source of injury is removed
- Cells involved:
- Plasma cells
Inflammation: Sequence of Microscopic Events
- Injury to tissue
- Constriction of microcirculation
- Dilation of microcirculation → hyperemia → erythema and heat
- Increase in permeability
- Exudate leaves microcirculation → transudate
- Increased blood viscosity
- Decreased blood flow
- Margination and pavementing of white blood cells (WBCs) → chemotaxis
- WBCs enter tissue → emigration → exudate and edema
- WBCs ingest foreign material → phagocytosis
microscopic events of inflammation
- they involve the small blood vessels or microcirculation.
- Can occur during acute and chronic inflammation
Factors Affecting Amount of Scar Tissue
- Strength and flexibility needed in the tissue
- Tissue type
- Type of repair
- Healing by primary intention
- Healing by secondary intention
- Healing by tertiary intention
Types of repair:
Healing by primary intention
- Healing of an injury in which there is little loss of tissue
- The margins are close together and very little granulation tissue forms
Types of repair:
Healing by secondary intention
- The edges of the injury cannot be joined during healing
- A large clot forms, resulting in increased granulation tissue
- May result in excess scar tissue: A keloid
Types of repair:
Healing by tertiary intention
- Delaying surgical tissue repair until infection is resolved
- An injured area may become infected, especially with puncture wounds
- In some situations, an infected injury is left open until infection is controlled
The small blood vessels, including arterioles, capillaries, and venues of the vascular system.
- chemicals in the body that activate responses
- May be derived from:
- Endothelial cells
- White blood cells and platelets
- Pathogenic organisms as they injure the tissue
- An excess of blood within blood vessels in a part of the body.
- Local clinical signs of inflammation are erythema and heat.
redeness of skin or mucosa.
Extravascular fluid component of blood that passes through the endothelial cell walls of the microcirculation.
process during inflammation in which white blood cells tend to move to the periphery of the blood vessel at the site of injury.
The adherence of white blood cells to blood vessel walls during inflammation.
The passage of white blood cells through the walls of small blood vessels and into injured tissue.
A body fluid with a high protein content that leaves the microcirculation during an inflammatory response that consist of serum that contains white blood cells, fibrin and other protein molecules.
Excess level of plasma or exudate in the interstitial space that results in tissue swelling.
An exudate that has a watery consistency. The consistency resembles that of serum.
An exudate containing pus or forming pus.
A collection of purulent exudate that has accumulated in a contained space formed by the surrounding tissue.
An abnormal passage that leads from an abscess to the body surface.
The movement of white blood cells as directed by biochemical mediators to an area of injury.
The ingestion and digestion of particulate material by cells.
white blood cells
The cells within the blood and surrounding tissue, also called leukocytes , that are involved in the inflammatory immune responses.
- The first white blood cell to arrive at a site of injury. primary cell involved in acute inflammation also called "polymorphonuclear leukocyte".
- constitute of 60%to 70%
- produced throughout life
- mobile cells
- function is phagocytosis of substances
Two types of white blood cells involved in the inflammatory response are
neutrophils and monocytes (macrophages)
- Active in early phases of inflammation
- Activated by substances in plasma and injured tissue
- Causes increased
- Dilation of blood vessels at the site of injury
- Permeability of local blood vessels
- Induces pain
- Clots blood and mediates inflammation
- Some of the clotting mechanism products that are activated during tissue injury cause local vascular dilation and permeability by activating kinin
- Involves the production of a sequential cascade of plasma proteins
- They are present in blood in an inactive form
- A trigger (usually an antibody-antigen complex) initiates the sequence of steps
- These plasma proteins function in inflammation and immunity
- Some components cause WBCs known as mast cells to release histamine
- Histamine causes an increase in vascular permeability and vasodilation
- Other components cause cell death, form chemotactic factors for WBCs, and enhance phagocytosis
- The second type of white blood cell to arrive at a site of injury that was originally a monocyte; it participates in phagocytosis during inflammation and continues to be active in the immune response.
- Constitute 3% to 8% of WBC population
- Single round nucleus and do not have granular cytoplasm
Cause increased vascular dilation and permeability, tissue pain and redness, and changes in connective tissue (CT)
- Act as chemotactic factors
- May cause damage to connective tissue and to the clot
- Produced by cell walls of gram-negative bacteria
- Serves as chemotactic factor; can activate complement, function as an antigen, and damage bone and tissue
The dissolution or destruction of a cell.
The enhancement of phagocytosis by a process in which a pathogen is marked, with opsonins, for destruction of phagocytes.
- An increase in the number of white blood cells circulating in blood.
- Normal number of WBCs per mm3 of blood: 4000 to 10,000
- In a systemic inflammatory response, the number increases to 10,000 to 30,000/mm3 of blood.
The abnormal enlargement of a lymph node or nodes.
- An elevation of body temperature to greater than the usual level of 37°C(98.6°F)
- Controlled by the hypothalamus
The fever-inducing substances produce from either white blood cells or photogenic microorganisms.
A decrease of white blood cells circulating in blood
The ring of lymphatic tissue formed by the two palatine tonsils, the pharyngeal tonsils, the lingual tonsils, and intervening lymphoid tissue.
- Nonsteroidal antiinflammatory drugs (NSAIDs)
- Acetylsalicylic acid (aspirin)
- Steroidal antiinflammatory drugs
- Cancer treatment drugs
C-reactive protein (CRP)
A nonspecific protein produced in the liver, that becomes elevated during episodes of acute inflammation or infection.
A lesion composed of a collection of macrophages usually surrounded by a rim of lymphocytes that is form by of chronic inflammation.
An enlargement of a tissue or organ resulting from an increase in the number of cells, the result of increased cell division.
A decrease in size or function of a cell, tissue, organ, or entire body
An enlargement of a tissue or organ resulting from an increase in the size of its individual cells, but not in the number of cells.
The process by which injured tissue is replaced with tissue identical to that present before the injury.
The restoration of damaged or disease tissue by cellular change and growth.
The cells that form fibers as well as intercellular substances.
The formation of fibrous tissue as usually occurs in healing.
The formation and differentiation of blood vessels.
The initial connective tissue formed in healing.
The process of renewal of a new surface layer of ephithelium.
Fibroblast that have some of the characteristics of smooth muscle cells, such as the ability to contract.
The excessive scarring that mainly occurs in skin in some cases with healing.
Factors delaying bone formation
- Blood supply at site
- Growth factors
- Removal of osteoblast-producing tissuesExcessive or inadequate movement of bone tissue
Factors influencing repair of bone
The cells that form bone.
Systemic factors that impair healing
- Genetic connective tissue disorders
- Metabolic disorders
Local factors that impair healing
- Bacterial infection
- Tissue destruction and necrosis
- Excessive movement of injured tissue
- Poor blood supply
The pathologic death of one or more cells, or a part of tissue, or an organ that results from irreversible damage to cells.
When tooth wear is increased by chewing and abrasive substances.
- Tooth-to-tooth wear
- May be observed in both primary and permanent dentition
- grinding of the teeth together for nonfunctional purposes.
- pathologic wearing away of tooth structure or a restoration that results from repetitive mechanical habit. (toothbrushing)
appears as wedge shaped defect at the cervical area of teeth. (stress)
- Loss of tooth structure resulting from chemical action without bacterial involvement.
- Methamphetamine abuse
- eating disorder characterized by binges, usually of very high caloric intake , followed by self induced vomiting.
eating disorder, intense fear of gaining weight and self-imposed starvation.
decrease salivary flow, craving for high sugar containing beverages combined with lack of hygiene care results in the extensive and rapid destruction of teeth that is called "meth mouth"