Cellular Adaption, Injury, and Death- Patho
Cellular hypoxia results in: increased pH. enhanced ATP activity. loss of intracellular calcium. failure of the sodium-potassium pump.
Failure of the sodium-potassium pump. Rational: Hypoxia is a loss of oxygen to the cell that causes ATP activity to cease. ATP provides the power required to drive the sodium-potassium pump. pH decreases in hypoxia (respiratory acidosis). Hypoxia is a loss of oxygen to the cell that causes ATP activity to cease. Deposits of calcium salts occur in conditions of altered calcium intake, excretion, or metabolism.
Livor Mortis
A dark blue staining of the dependent surface of a cadaver, due to the pooling and congestion of blood.
Atrophy
A reduction in size and function of a cell or tissue; wasting.
A patient who is 85 years old reports to a healthcare provider every year for a flu shot. This is important preventative intention because:
immune and respiratory reserves decline with age.
Physiologic Changes of Aging
Cardiovascular: decreased vessel elasticity Respiratory: Decreased respiratory muscle strength Renal/urinary: decreased ability to concentrate urine Gastrointestinal: decreased bowel motility Neurologic/Sensory: loss of taste buds Musculoskeletal: decreased muscle mass Immune: decreased inflammatory response Integumentary: decreased subcutaneous fat
Hyperplasia
Abnormal multiplication or increase in the number of normal cells in normal arrangement in a tissue.
Cellular Basis of Aging
Aging of cells is different from disease, it is thought to result from accumulated DNA damage, decreased proliferate capacity of stem cells, increased presence of free radicals, programmed cell death.
Dysplasia
An alteration in cellular growth in which cell morphologic characteristics are variable and disorderly. May become cancerous.
Hypertrophy
An increase in cell or tissue size and function
Viruses injure cells differently than other causes of cellular injury because they produce and secrete powerful destructive enzymes that digest cellular membranes and connective tissues. are incorporated into the cell, where it uses the cell's RNA or DNA for self-replication. cause reperfusion injury as the result of free radical formation. injure cells by disrupting chemical bonds through ionization.
Are incorporated into the cell, where it uses the cell's RNA or DNA for self- replication. Rational: Viruses are small bits of genetic material that are able to gain entry into the cell. They may be thought of as intracellular parasites that use the host cell's metabolic and synthetic machinery to survive and replicate. Some bacteria produce and secrete powerful destructive enzymes that digest cellular membranes and connective tissues. Cell death results from ischemia and the resulting formation of reactive oxygen molecules (free radicals). Chemical injuries can result for the disruption of chemical bonds.
A client develops weakness in both lower extremities following a prolonged period of bed rest. This condition is most likely caused by atrophy. dysplasia. hypertrophy. hyperplasia.
Atrophy. Disuse atrophy develops after prolonged periods of inactivity as a result of shrinkage of skeletal muscle cells. Dysplasia results in the abnormal development or growth of tissues, organs, or cells. Hypertrophy is an increase in cell mass accompanied by an augmented functional capacity. Cells hypertrophy in response to increased physiologic or pathophysiologic demands. Hyperplasia increases the cell's functional capacity by increasing the number of cells. Hyperplasia usually results from increased physiologic demands or hormonal stimulation.
Which type of cellular adaptation is most likely to occur as the result of chronic ischemia to a region? Hypertrophy Hyperplasia Metaplasia Atrophy
Atrophy. Rational: Ischemia is inadequate blood supply to a tissue. Chronic sublethal ischemia usually results in cell atrophy. Hypertrophy would result in an increase in cell size in response to increased physiologic demand. Hyperplasia would result in an increased number of cells in response to increased physiologic demand. Metaplasia is the replacement of one differentiated cell type with another better suited for the situation.
Which cellular response is maladaptive? Shrinkage of cell size Increase in cell size Increase in the number of cells Change in the shape or arrangement of cells
Changes in the shape or arrangement of cells. Rational: Dysplasia (abnormal variations in shape and arrangement of cells) represents an unsuccessful attempt of the cells to adapt. Cells shrink in response to a migration of fluid to balance fluid loss elsewhere in the body. Cells hypertrophy (increase in size) in response to increased physiologic or pathophysiologic demands. Cells that are capable of mitotic division generally increase their functional capacity by increasing the number of cells (hyperplasia) as well as by hypertrophy. Hyperplasia usually results from increased physiologic demands or hormonal stimulation. Persistent cell injury also may lead to hyperplasia.
Causes of Cell Injury: Chemical Injury
Chemical: glucose Ischemic and Hypoxic Nutritional Physical and mechanical infectious and immunologic
Four types of Necrosis
Coagulative- heart (Dry Gangrene), liquefactive(wet gangrene-brain), fat (pancreatitis), and caseous(lung-TB)
Necrosis
Death and degradation of body cells or tissues in response to irreversible injurious events.
A critical event in the death of a cell is caused by disruption of the plasma membrane's permeability barrier. an increase in cellular protein content. an accumulation of lipofuscin. chronic nutrient insufficiency.
Disruption of the plasma membrane's permeability barrier. Rational: Disruption of the plasma membrane barrier, seen in necrosis, results in cellular death. Hypertrophy results primarily from a net increase in cellular protein content. Atrophy can result in the accumulation of lipofuscin. Atrophy occurs when cells shrink and reduce their differentiated functions in response to a variety of normal and injurious factors, such as nutrient starvation.
Which type of cellular adaptation would create the greatest concern if found on a biopsy report? Dysplasia Metaplasia Hyperplasia Hypertrophy
Dysplasia. Rational: Dysplastic cells have significant potential to transform into cancerous cells and are usually regarded as preneoplastic lesions. Metaplasia is the replacement of one differentiated cell type with another. This most often occurs as an adaptation to persistent injury, with the replacement cell type better able to tolerate the injurious stimulation and is fully reversible when the injurious stimulus is removed. Hyperplasia is an increase in cell number usually in response to physiologic demands, hormonal stimulation, or chronic cell injury. This is generally a normal adaptation, and not nearly the concern of the correct option. Hypertrophy is an increase in cell mass accompanied by an augmented functional capacity. This is generally a normal adaptation, and of little or no concern.
Reperfusion injury following an ischemic episode results in further tissue damage due to:
Excessive Intracellular Calcium
Which is a theory of aging? (Select all that apply.) Apoptosis Free radical Immunologic Nutritional injury Programmed senescence
Free Radical, programmed senescence. Rational: The free radical theory states that aging may also be a result of accumulated metabolic cell damage over time. The programmed senescence theory holds that aging is the result of an intrinsic genetic program. Apoptosis, a type of cellular suicide, is a common event that regulates normal system function. Immunologic theory explains the role of the immune system in cellular injury. Nutritional injury is a common cause of dysfunction and disease, but there is no known relationship to aging.
What is the mechanism of cellular injury that occurs when deep sea divers get "the bends"? Intracellular calcium accumulation creates muscle tetany. Gas bubbles form in the blood, blocking circulation and resulting in ischemia. Free radicals form abnormal chemical bonds, which destroy the cellular membranes. Carbon monoxide binds tightly to hemoglobin, preventing the red blood cells from carrying oxygen.
Gas bubbles form in the blood, blocking circulation and resulting in ischemia. Rational: Abrupt changes in atmospheric pressure may result from high-altitude flying, deep sea diving, and explosions. Pressure changes may interfere with gas exchange in the lungs, cause the formation of gas emboli in the bloodstream, collapse the thorax, and rupture internal organs. A well-known example of pressure injury is the condition of "the bends," which afflicts deep sea divers who surface too quickly. The rapid decrease in water pressure results in the formation of bubbles of nitrogen gas in the blood, which may block the circulation and cause ischemic injury. Cell injury results from deficiencies, as well as from excesses of essential nutrients, such as in the case of excessive calcium and the resulting tetany. The free radical is very reactive, forming abnormal chemical bonds in the cell and ultimately destroying the cellular membranes. Some toxins have an affinity for a particular cell type or tissue, whereas others exert widespread systemic effects. For example, carbon monoxide binds tightly and selectively to hemoglobin, preventing the red cell from carrying sufficient oxygen.
A heart that has to pump harder in order to effectively circulate blood is likely to undergo which type of cellular adaptation? Atrophy Metaplasia Hypertrophy Hyperplasia
Hypertrophy. Rational: Cells hypertrophy in response to increased physiologic or pathophysiologic demands. If the heart has to pump harder than normal to meet the body's demand for oxygen and nutrients, the cardiac cells will become larger, resulting in cardiac hypertrophy. Atrophy results in cell death that would render the cells non-functional. Metaplasia is the replacement of one differentiated cell type with another. Muscle contraction could possibly be lost rather than enhanced. Hyperplasia would result in an increased number of cells rather than an enhanced pumping capacity.
A patient who is 85 years old reports to a health care provider every year for a flu shot. This is important preventative intervention because:
Immune and Respiratory reserve decline with age.
Causes of Cell injury: Ischemia/Hypoxic Injury
Ischemia- (Most Common) A temporary deficiency of blood flow to an organ or tissue. The deficiency may be caused by diminished blood flow either through a regional artery or throughout the circulation. Hypoxia- An oxygen deficiency in body tissues. A decreased concentration of oxygen in inspired air.
Examples of Intacellular Accumulations
Lipids (fatty liver) Carbohydrates (mental disabilities) Glycogen (DM) Proteins
Signs/Symptoms of Necrosis
Malasie, fever, increased heart rate, increased WBC's, loss of appetite
Which type of irreversible cell injury initiates an inflammatory response?
Necrosis
Causes of Cell Injury: Nutritional Injury
Poor Intake(malnutrition), altered cellular absorption, impaired distribution, inefficient cellular reuptake, excess intake(obesity-heart disease, diabetes)
Apoptosis
Programmed cell death; characterized by DNA degradation and cell dissolution, but without necrosis. Normal physiological process. Does not cause inflammatory response.
Cellular Aging
Progressive decline in proliferation and reparative capacity of cells. Telomeres shorten.
Compare and contrast reversible and irreversible cell injury/death
Same: cellular swelling and accumulation of excess substances within the cell.
An increase in which of these characteristics would be present in cells that demonstrate hypertrophy? Lipofuscin Size of vacuoles Size of cells Number of cells
Size of Cells. Rational: Hypertrophy is defined as an increase in cell mass (cellular enlargement). A lipofuscin is a yellow to brown, granular, iron-negative lipid pigment found particularly in muscle, heart, liver, and nerve cells; it is the product of cellular wear and tear, accumulating in lysosomes with age. A vacuole is a small cavity in the cytoplasm of a cell, bound by a single membrane and containing water (hydropic swelling), food, or metabolic waste. Cells that are capable of mitotic division generally increase their functional capacity by increasing the number of cells by hyperplasia.
In muscle hypertrophy, the hypertrophied cells increase in size. number. calcium. accumulations.
Size. Rational: The cellular response to persistent, sublethal stress reflects the cell's efforts to adapt. A common adaptive response is hypertrophy resulting in an increase in cell size. Hyperplasia is an increase in cell number. An increase in calcium would be pathologic and likely result in tetany. An increase in accumulations would be pathologic and likely result in cell injury.
Which condition occurs in the presence of cellular damage? Cells shrink. ATP production increases. Osmotic pressure decreases. Sodium and water move into the cell.
Sodium and water move into the cell. Rational: Cellular injury causes failure of the sodium-potassium pump, resulting in migration of sodium ions into the cell. The accumulation of intracellular sodium creates an osmotic gradient that pulls water into the cell, resulting in hydropic swelling. Cells actually swell, not shrink, as a result of cellular damage. Cellular damage results in the cell's inability to perform normal metabolic functions owing to insufficient cellular energy in the form of adenosine triphosphate (ATP). Osmotic pressure increases to accommodate for swelling.
Postmortem Autolysis
The Spontaneous destruction of tissues by intracellular enzymes. It generally occurs in the body after death.
Algor Mortis
The reduction in body temperature and accompanying loss of skin elasticity that occur after death. Also called death chill.
Rigor Mortis
The stiffness that occurs in dead bodies.
Necrosis is the result of cellular injury that does not allow for cellular adaptation because it is which of the following? (Select all that apply.) Too severe Too prolonged Acute in nature Programmed into the cell itself A result of a disrupted blood supply
Too severe, too prolonged, and a result of a disrupted blood supply. Rational: Necrosis occurs when the injury is too severe and too prolonged to allow adaptation to the stressors. Necrosis is usually a consequence of disrupted blood supply. A short-term injury usually allows the cell to adapt and so avoid necrosis. Apoptosis controls the rate of cell division and the rate of cell death. If cells are no longer needed, they activate a cellular death pathway, resulting in cell suicide.
Metaplasia
Transformation of one kind of tissue to another fully differentiated tissue.
Causes of Cell Injury: Infectious/Immunologic Injury
Viral Infection or host's immune system destroys own host's cells.
Hydropic Swelling
cellular swelling due to accumulation of water. Malfunction of sodium-potassium pump. (Splenomegaly, hepatomegaly)
Poikilothermia
the inability to regulate core body temperature
