Week 3- Injury, Inflammation, Healing and Repair Flashcards
The structural and functional changes in the body caused by disease or trauma
Pathology
What do the structural and functional changes produced by pathology start with?
Injury to the cells that make up the tissues
What does mild injury produced by stressors leads to?
Sublethal alterations of the affected cells that may be reversible
What does moderate/severe injury leads to?
Lethal alterations that are likely irreversible and can lead to cell death
True or false: Cell injury may be reversible or irreversible
True
What determines if an injury is reversible?
The cell’s ability to withstand the derangement of homeostatic mechanisms and its adaptability
What is reversing the injury and achieving homeostasis determined by?
-Mechanism of injury
-Length of time the injury is present without intervention
-Severity of the injury
When does ischemia occur?
Blood flow is insufficient to maintain cell homeostasis and metabolic function
What are the causes of cell injury?
-Ischemia
-Infectious agents
-Immune reactions
-Genetic factors
-Nutritional factors
-Physical factors
-Chemical factors
What does insufficient blood flow result in?
-partial/total reduction in oxygen supply
-decreased delivery of nutrients
-decreased removal of waste products from the tissue
What does lack of oxygen lead to?
Loss of aerobic metabolism
True or false: The resulting reduction in ATP synthesis leads to accumulation of ions and fluid intracellularly, causing the cells to swell.
True
Ischemia resulting in _______ or __________ can cause ________ and accounts for two of the three leading causes of mortality in industrialized nations
-myocardial infarction
-stroke
-necrosis (death of tissue)
What are responsible for most infections?
Bacterial and viral agents
How do bacterial infections cause cell injury?
Invading tissue and releasing exotoxins and endotoxins that can cause cell lysis and degradation of extracellular matrix and aid in the spread of the infection
Term for involuntary muscle contractions
Tetanus
Endotoxins released from gram-negative bacteria induce the synthesis of _________and ________ that are responsible for many of the systemic
manifestations of sepsis.
-cytokines
-interleukins
Cardiovascular collapse may lead to a condition called ______________.
Septic shock
True or False: The detection of an infectious agent initiates an
inflammatory reaction designed to contain and inactivate the pathogen, but the magnitude of this defensive response by the host may also cause
cellular or tissue destruction in the infected area.
True
What are two ways viruses kill cells?
-Kill from within by disturbing various cellular processes or by disrupting the integrity of the nucleus and/or plasma membrane
-Virally encoded proteins become inserted into the plasma membrane of the host cell (forming a channel) and alter the permeability of the cell membrane to ions
True or false: Viruses do not integrate themselves into the cellular genome
False
What happens when the immune system is compromised or if the number of invading microorganisms overwhelms the immune system?
Disease
What are the mechanisms by which the immune system can lead to cell injury/death?
-antibody attachment
-complement activation
-activation of the inflammatory cells
What are some ways the immune system can cause cell injury and disease?
-Allergies
-Severe hypoxia
-Cross reactivity between foreign and host antigens
How are toxic substances divided?
-Substances than can injure cells directly
-Substances that require metabolic transformation into the toxic agent
Example of drug-induced chemical toxicity
Suicide via drug overdose
Another term for reactive oxygen species
Free radicals
A variety of normal and pathologic reactions can lead to the activation of _______ by the sequential addition or subtraction,
respectively, of one electron at a time.
Oxygen
True or false: Free radicals only exert positive effects
False
(they exert positive or negative effects)
True or false: Free radicals are an integral part of metabolism and formed continuously
True
What happens when a normal oxygen atoms lose one of their four paired electrons?
A chain reaction occurs
True or false: The cellular enzymes always scavenging the body to protect cells from
injury normally inactivate radicals and convert the free
radical back to usable oxygen.
True
True or false: Some unstable oxygen molecules (i.e., free
radicals) enable the body to fight inflammation, kill bacteria, and help regulate the autonomic nervous system.
True
Situation when radicals are produced in excess amounts
Oxidative stress
Research has
shown that oxidative stresses caused by ROS are factors in more than ______%
of lifestyle-related diseases
90%
Oxidation as a by-product of metabolism damages _________, leading to intrinsic cellular damage, a part of the normal aging process
Cell membranes
Other causes for free radical formation
-Exposure of toxic chemicals
-Exposure to high level of oxygen
-Irradiation
-Ultraviolet
-Fluorescent light
-Pollutants
-Tobacco smoke
-Pesticides
-Drug overdose
-Heat stress
-Reperfusion injury
-Prolonged exercise
What neutralizes extra free radicals and stop chain reactions?
Antioxidants
A variety of enzymatic and nonenzymatic
defense mechanisms are present within cells to perform the function of
antioxidants detoxifying ROS and protecting the cells from this type of
injury.
Endogenous antioxidants
This can be obtained from outside the body through diet (in food and plant substances)
Exogenous antioxidants
True or False: Moderate physical activity and exercise strengthen the antioxidant defense system
True
True or false: Intense or prolonged, strenuous exercise (especially in person with a sedentary lifestyle) does not lead to oxidative stress
False
This molecule is present in all mammals including humans and is one of the few gaseous signaling molecules known
NO (nitric oxide)
What are the three primary ways genetic alterations lead to cellular injury/death?
-Alterations in the structure or number of chromosomes that
induce multiple abnormalities
-Single mutations of genes that cause changes in the amount or functions of proteins
-Multiple gene
mutations that interact with environmental factors to cause multifactorial
disorders
Examples of alterations in the structure or number of chromosomes that induce multiple abnormalities
Down syndrome: 3rd chromosome in 21st pair
Examples of single mutations of genes that cause changes in the amount or functions of proteins
Sickle cell anemia, low-density lipoprotein receptor deficiency, and α-antitrypsin deficiency
Examples of multiple gene mutations that interact with environmental factors to cause multifactorial disorders
Hypertension and type 2 diabetes
Proposes that changes in the relative level of physical stress cause a predictable adaptive response in all biologic tissue
Physical stress theory
Typical tissue response to physical stress includes:
-decreased stress tolerance (atrophy)
-maintenance
-increased stress tolerance (hypertrophy)
-injury
-death
When does failure of a tissue occur?
Applied load exceeds the failure tolerance of the tissue
What are soft tissues influenced by?
History of recent physical stresses so that the accumulation of individual stresses can cause injury
What determines the inflammatory response?
The time elapsed since injury and the extent of tissue damage
What could result from at traumatic accident?
Fractured bones and/or ruptured ligaments
What are other causes of tissue injury?
-Repeated episodes of moderate magnitude force
-Slow degradation of tissue tolerance
-Low loads sustained over a long period
True or False: Imbalances in essential nutrients can lead to cell injury or cell death
True
Consequence of protein malnutrition
Kwashiorkor
Consequence of generalized dietary deficiency
Marasmus
True or false: Nutritional imbalance never occur as a result of abnormal levels of either vitamins or minerals
False
What is a leading cause of death in the United States?
Blunt trauma resulting from motor vehicle accidents
What can lead to immediate mortality due to blunt trauma?
-Massive brain contusions
-Injury to internal organs and soft tissues
-Blood loss
True or false: Survivors of blunt trauma may die later of infections and multiple organ failure
True
Cells may be damaged by extremes of physical agents such as ___________, ______________, and ____________.
-Temperature
-Radiation
-Electricity
True or false: Psychosocial factors (e.g., fear, tension, or
anxiety) do not influence individual threshold values for tissue adaptation
and injury.
False
This occurs if the stress is sufficiently small in magnitude or short enough in duration that the cells is able to recover homeostasis after removal of the stress
Reversible cell injury
This occurs when the injurious/stressful stimulus is of sufficient magnitude or duration or if the cell is unable to adapt
Irreversible cell injury
____________ enables the cells to function in an altered environment and thereby avoid injury
Adaptation
True or false: All changes due to cell adaptation benefit the function of the parent organ or structure within which the cell resides
False
(not all)
What are common cellular adaptations?
-atrophy
-hypertrophy
-hyperplasia
-metaplasia
-dysplasia
The reduction in cell and organ size
Atrophy
An increase in the size of the cell and organ
Hypertrophy
True or false: Atrophy can occur with vascular insufficiency, reduction in hormone levels, malnutrition,
immobilization, pain that limits movement and function, and chronic
inflammation.
True
When can hypertrophy occur?
Increased functional demands are placed on the cells, tissues, or organs with increased hormonal input
An increase in the number of cells, leading to increased organ size
Hyperplasia
A change in cell morphology and function resulting from the conversion of one adult cell type into another
Metaplasia
An increase in cell numbers that is accompanied by altered cell morphology and loss of histologic organization
Dysplasia
True or false: Aging and age-related changes do not influence homeostasis and the recovery process
False
What is a prime target for age-related changes?
Mitochondrial DNA
Aging-pigment granule, found in high concentrations in older/postmitotic cells
Lipofuscin
How many theories of cellular aging are there?
More than 300
Mechanism of cellular aging
Deceased capacity to respond to stress –> progressive decline in homeostatic balance –> pathology
True or false: Pathologic changes associated with aging vary from person to person, but usually consist of reduced functional reserve caused by atrophy of tissues or organs
True
Increases in the storage of lipids, proteins,
carbohydrates, or pigments within the cell that occur as a result of an
overload of various metabolites or exogenous material
Intracellular accumulations
Programmed cell death that is genetically mediated and overall physiologic
Apoptosis
What does apoptosis begin with?
Either an activation of a trigger or stimulus or the suppression of a specific agent that then allows the process of cell death to occur
The active process of degradation of dead cells and is the end point of a pathologic process (leads to lethal, irreversible cell injury)
Necrosis
What is acute inflammation triggered by?
-infections
-tissue necrosis
-foreign bodies
-immune reactions
Four cardinal signs/symptoms of inflammation
-erythema
-heat
-edema
-pain
The process of inflammation is initiated after cell injury through what mechanisms?
The amount, type, and severity of the inflammatory reaction are dependent on the amount, type, and severity of the injury
What is the purpose of inflammation?
-remove injurious agent
-remove cellular debris
-initiation of healing process
True or false: Normally, inflammation has a protective role and is generally beneficial to the body
True
True or false: Inflammation can be detrimental and has the potential of causing damage to adjacent healthy tissue
True
Inflammation of sudden onset and short duration
Acute inflammation
Main characteristics of acute inflammation
-edema
-migration of leukocytes (mainly neutrophils)
Inflammation that does not resolve but persists over time
Chronic inflammation
Main characteristics of chronic inflammation
-lymphocytes and macrophages
-proliferation of blood vessels and fibrosis
-tissue destruction
PG 820
Clostridium tetani releases an exotoxin that is preferentially absorbed by the alpha motor neurons and delivered into the central nervous system. What is the cause of injury to the neuron cell?
-Infectious agent
-Chemical factor
-Immune reaction
-Psychosocial factor
Infectious agent
What happens when the immune system is compromised or if the number of invading microorganisms overwhelms the immune system?
-Death occurs
-Disease occurs
-Cellular aging occurs
-All the above
Disease occurs
Which of the following conditions is generally not thought to be caused by free radicals?
-Rheumatoid arthritis
-Heart disease
-Diabetes mellitus
-Cerebrovascular disease
Rheumatoid arthritis
What is the correct term for protein malnutrition?
-Anemia
-Kwashiorkor
-Marasmus
-Ascites
Kwashiorkor
During acute reversible cell injury, the concentrations of which two elements are increased?
-Sodium and potassium
-Calcium and potassium
-Sodium and calcium
-Calcium and magnesium
Sodium and calcium
Which of the following is a change in cell morphology and function resulting from the conversion of one adult cell type into another?
-Metaplasia
-Hyperplasia
-Dysplasia
-Atrophy
Metaplasia
Pure hypertrophy occurs only where in the body?
-Heart and smooth muscles
-Smooth and striated muscles
-Heart and striated muscles
-Nerve cells and striated muscles
Heart and striated muscles
Hypertrophy of what chamber of the heart is a typical complication of hypertension?
-Left ventricle
-Left atrium
-Right ventricle
-Right atrium
Left ventricle
Which of the following statements regarding necrosis of cells is true?
-Plasma membranes are intact
-There is no adjacent inflammation
-Cellular contents remain in the cell at all times
-Cell size increases
Cell size increases
The presence of which types of cells is associated with chronic inflammation?
-Leukocytes
-Macrophages
-Neutrophils
-T cells
Macrophages
What type of inflammatory exudate is bright red or bloody and signals the presence of red blood cells?
-Sanguineous
-Purulent
-Seroanguineous
-Serous
Sanguineous
What is the first step in the migration of leukocytes from the vasculature to the interstitial tissues?
-Binding of leukocytes to receptors on endothelial cells of venules
-Chemotaxis
-Release of neutrophils
-Diapedesis
Binding of leukocytes to receptors on endothelial cells of venules
What is the approximate life cycle of a neutrophil after extrusion from the circulation?
-48 hours
-6 hours
-24 hours
-12 hours
24 hours
In which of the following cells is histamine not stored?
-Neutrophils
-Basophils
-Platelets
-Mast cells
Neutrophils
What is secreted by fibroblasts early during the tissue repair reaction?
-Type I Collagen
-Elastin
-Fibronectin
-Proteoglycans
Proteoglycans
What type of collagen is the predominant component of growth plates in bones?
-Type I
-Type II
-Type III
-Type IV
Type II
What is the true phases of healing?
Hemostasis and degeneration –> Inflammation –> Proliferation and migration –> Remodeling and maturation
Hemostasis and degeneration –> Proliferation and migration –> Remodeling and maturation –> Inflammation
Inflammation –> Hemostasis and degeneration –> Remodeling and maturation –> Proliferation and migration
Hemostasis and degeneration –> Inflammation –> Remodeling and maturation –> Proliferation and migration
Hemostasis and degeneration –> Inflammation –> Proliferation and migration –> Remodeling and maturation
Which of the followings about cell injury is true?
-Dysplasia is a type of irreversible cell injury.
-Apoptosis is a programmed cell death.
-Necrosis is one of the possible adaptions after the cell receives sustained stress.
-Atrophy is a type of irreversible cell injury.
Apoptosis is a programmed cell death.
Which of the following is the LEAST appropriate for a physical therapist to do during patient’s healing process?
-Maintain the normal function of non-injured tissue and body regions.
-Provide patient education about tissue healing process.
-Suppress inflammatory process as soon as possible.
-Limit the cause of injury by identifying and modifying it.
Suppress inflammatory process as soon as possible
What is the primary indication of prednisone?
-Hypertension
-Congestive heart failure
-Hyperlipidemia
-Anti-inflammatory
Anti-inflammatory
What is the drug class for celecoxib?
-Cyclooxygenase type 2 (COX-2) inhibitors
-Glucocorticoids
-Angiotensin-II receptor blockers
-Beta blockers
Cyclooxygenase type 2 (COX-2) inhibitors
Which of the following factors would affect tissue healing?
-Vascular sufficiency
-Caffeine
-Immobility
-All the above
All the above
The time for overall bone healing varies depending on
-The bone involved and degree of soft tissue injury
-Treatment required (e.g., immobilization versus surgical repair, the need for bone grafting or use of bone graft substitutes)
-The fracture site and type
-All the above
All the above
Which of the following is true for tendon injury and healing?
-The maturation and remodeling phase typically begins around 24 hours after the initial injury
-Hemostasis begins immediately, followed by the inflammatory process, which begins during the first 72 hours (3 to 5 days) after injury or surgical intervention
-The immature type I collagen is replaced by mature type IV collagen during the maturation and remodeling phase
-All the above
Hemostasis begins immediately, followed by the inflammatory process, which begins during the first 72 hours (3 to 5 days) after injury or surgical intervention
