NU 271 Chapter 3: Cellular Adaptation, Injury, and Death
A client who has a diagnosis of lung cancer is scheduled to begin radiation treatment. The nurse knows that which statement about potential risks of radiation is most accurate? "The changes that you might see are normally irreversible." "Sometimes you might find that your blood takes longer to clot than normal." "Some clients experience longer-term irritation of skin adjacent to the treatment site." "The unwanted effects will be limited to the exposed portions of your skin."
"Some clients experience longer-term irritation of skin adjacent to the treatment site." Explanation: Chronic radiation dermatitis is a consequence of cancer treatment with ionizing radiation. Hypocoagulation is not an identified consequence of radiation exposure, and changes can be both reversible and deeper than the surface of the skin.
A client with pulmonary hypertension has hypertrophy of the heart's right ventricle. Which explanation is appropriate to tell the client? "The cells enlarge in your heart from the increased workload." "Hypertrophy is a result of necrotic changes from hypoxia." "As your heart works harder, the number of cells increases." "As cells in your heart die, they get smaller."
"The cells enlarge in your heart from the increased workload." Explanation: Hypertrophy is an increase in cell size due to increased work demands. A client with pulmonary hypertension has increased pressure in the lungs, which the right side of the heart must pump against. The increased work causes cells to increase in size. This is different from an increase in the number of cells, which is hyperplasia. Damage from hypoxia is ischemia, and cells that get smaller is called atrophy.
Which statement would a nurse tell a client that best describes a lab finding of metaplasia? "This is a decrease in the oxygen-carrying capacity of the cells." "This is a decrease in the size of the cell." "This is a change in cell form as it adapts to increased work demands or threats to survival." "This is a change in the number of cells as they adapt to change."
"This is a change in cell form as it adapts to increased work demands or threats to survival." Explanation: Metaplasia is a change in the cell's form as it adapts to increased work demands or threats to survival. Hyperplasia is the change in the number of cells, and atrophy and hypertrophy are changes in a cell's size. Hypoxia or hypoxemia are decreases in oxygen.
Of the following situations, which one would be an example of a maladaptive cellular change? 31-year-old marathon runner who has developed hypertrophied myocardial cells 44-year-old male with a 60 pack/year smoking history who was diagnosed with a histological grade-3 lung cancer 54-year-old female who has developed ovarian atrophy following loss of estrogen stimulation during menopause 18-year-old body builder who has developed extremely large pectoral muscles following years of weight lifting.
44-year-old male with a 60 pack/year smoking history who was diagnosed with a histological grade-3 lung cancer Explanation: In many adaptive cellular responses, the expression of the differentiation genes is altered. When working with cancer clients, histological grade or differentiation refers to how much the tumor cells resemble normal cells of the same tissue type. In body builders and athletes, cells hypertrophy based on the increase in workload placed on the muscle. Reproductive atrophy is expected due to the loss of estrogen stimulation during menopause.
A nurse is caring for four clients. Which client is at greatest risk for high blood levels of lead? A 17-year-old student who takes a woodworking class A 30-year-old office worker with asthma A 62-year-old smoker with hypercalcemia A 2-year-old anemic child who lives in a turn-of-the-century home
A 2-year-old anemic child who lives in a turn-of-the-century homeExplanation: The client at the highest risk of having higher blood levels would be a young child who is likely to puts small toys in his or her mouth or ingests lead dust form soil. Factors that increase the risk of lead toxicity include preschool age, low socioeconomic status, and living in older housing built primarily before 1960. A client with a deficiency in calcium (hypocalcemia), iron, or zinc increases his or her risk of lead absorption. Behaviors that include smoking and working around wood have no apparent affect on the development of lead poisoning.
Which client would be an example of an individual experiencing cellular atrophy? A hypertensive, noncompliant client who has developed a progressive increase in left ventricular mass A postnephrectomy client whose remaining kidney enlarges to compensate for the loss A female client with the change in uterine size as a result of pregnancy A middle-aged female experiencing menopause due to loss of estrogen stimulation
A middle-aged female experiencing menopause due to loss of estrogen stimulation Explanation: In women, the loss of estrogen stimulation during menopause results in atrophic changes in the reproductive organs. Compensatory hypertrophy is the enlargement of a remaining organ or tissue after a portion has been surgically removed or rendered inactive. For instance, if one kidney is removed, the remaining kidney enlarges to compensate for the loss. In hypertension, for example, the increased workload required to pump blood against an elevated arterial pressure results in a progressive increase in left ventricular muscle mass and need for coronary blood flow. The pregnant uterus undergoes both hypertrophy and hyperplasia as a result of estrogen stimulation.
A client is experiencing muscle atrophy following 2 weeks in traction after a motor vehicle accident. Which factor has most likely contributed to the atrophy of the client's muscle cells? Denervation of the affected muscles during the time of traction A reduction of skeletal muscle use secondary to the traction treatment Reduced oxygen consumption and cellular function that ensures muscle cell survival High levels of insulin and IGF-1 in the client's blood during immobilization
A reduction of skeletal muscle use secondary to the traction treatment Explanation: Disuse atrophy results from the reduction in skeletal muscle use such as that following encasement in plaster casts or traction. Low levels of insulin and IGF-1 contribute to atrophy, and denervation only occurs in paralyzed limbs. Reduced oxygen consumption and cellular function are the mechanisms of cell atrophy but not the causes of the process.
The nurse is reviewing the effects of various pharmaceutical agents. Which fact about the effect of medications on the body will the nurse apply in practice? Drugs only have positive effects on cells. Antineoplastic drugs directly damage cells. Drugs only have bad effects when they have side effects. Drugs do not injure tissues or cells.
Antineoplastic drugs directly damage cells. Explanation: Antineoplastic drugs directly injure cells. Many drugs injure tissues and cells either through their direct mechanism of action, side effects, or adverse effects.
A nurse is triaging clients at a disaster site. Local facilities have different specialized units. To what facility should the nurse send a client who has sustained an electrical injury to his left thigh? Cardiac care unit Burn unit Neurology unit Surgical intensive care unit
Burn unit Explanation: An electrical injury to an area containing bone and muscle will have high resistance and create a high degree of local skin burn, so a burn unit is most appropriate. If the injury had been to the torso this may result in more respiratory or cardiac complications. If the client receives surgery, a surgical intensive care unit may be accessed but cardiac care and neurology do not have immediate priority over a burn unit.
Which process associated with cellular injury is most likely to be reversible? Cell damage resulting from accumulation of free radicals Cellular changes as a result of ionizing radiation Apoptosis Cell damage resulting from accumulation of fat in the cytoplasm
Cell damage resulting from accumulation of fat in the cytoplasm Explanation: Intracellular accumulation of fat leads to serious cell damage, but this is a potentially reversible effect. Ionizing radiation and damage from free radicals are more likely to be permanent, whereas apoptosis is defined as the permanent removal of injured and aged cells.
A client's ECG reveals that he is suffering from a myocardial infarction. Prompt interventions are chosen to minimize further myocardial harm. What damage is the care team trying to prevent? Oxidative stress-induced damage Cellular atrophy Cellular hypoxia Apoptotic tissue damage
Cellular hypoxia Explanation:The care team will implement interventions to prevent cellular hypoxia. Oxidative stress cannot be avoided in this situation, and apoptosis does not apply to tissues. Oxygen deprivation does not cause cellular atrophy.
The client is found to have liver disease, resulting in the removal of a lobe of the liver. Adaptation to the reduced size of the liver leads to which phenomenon in the remaining liver cells? Physiologic hypertrophy Compensatory hyperplasia Metaplasia Organ atrophy
Compensatory hyperplasia Explanation: Compensatory hyperplasia can be stimulated in response to loss of vital tissue that is capable of regeneration, such as liver cells. Metaplasia involves replacement of one existing cell type with another fully differentiated cell type. Organ atrophy is caused by irreversible loss of cells. Physiologic hypertrophy is increased size of existing cells resulting from increased workload.
A client has suffered nerve damage in his right arm. What can the nurse expect to happen to the muscles in that arm? Changes in the form of the cells (metaplasia) Decrease in the size of the cells (atrophy) Increase in number of cells (hyperplasia) as they adapt to change Increase in size (hypertrophy) as the cells adapt to the change
Decrease in the size of the cells (atrophy) Explanation: The general causes of atrophy can be grouped into five categories: disuse, denervation, loss of endocrine stimulation, inadequate nutrition, and ischemia. If a client has no innervation to the muscles in the arm, the muscle cells can atrophy from disuse.
Which situation causes atrophy? Select all that apply. Increased nutrition Increased endocrine stimulation Disuse Denervation Decreased blood flow
Disuse Denervation Decreased blood flow Explanation: Atrophy is caused by disuse, denervation, decreased blood flow, decreased endocrine stimulation, and decreased nutrition.
Assessment of a client with diabetes reveals that the toes are dark in color and the skin is shrunken and wrinkled, with a clear delineation between affected and unaffected regions. This client likely has: wet gangrene. gas gangrene. dry gangrene. liquefactive gangrene.
Dry gangrene is marked by a distinct area that becomes dry and shrinks; the skin wrinkles and its color changes to dark brown or black. Wet gangrene is marked by an area that is cold, swollen, and pulseless. Gas gangrene is the result of infection. Liquefactive gangrene is used to refer to a type of necrosis that will lead to wet gangrene.
A client's lab report returns and a nurse is explaining to the client the significance of the changes. The nurse states that the finding is implicated as a precursor of cancer. Which finding was most likely on the lab report? Dysplasia Metaplasia Atrophy Hypertrophy
Dysplasia Explanation: Dysplasia is characterized by deranged cell growth of a specific tissue that results in cells that vary in size, shape, and organization. It is strongly implicated as a precursor of cancer.
Biologic agents differ from other injurious agents in that they are able to replicate and can continue to produce their injurious effects. How do Gram-negative bacteria cause harm to the cell? Gram-negative bacilli release endotoxins that cause cell injury and increased capillary permeability. Gram-negative bacilli cannot cause harm to the cell; only Gram-positive bacilli can harm the cell. Gram-negative bacilli excrete elaborate exotoxins that interfere with cellular production of ATP. Gram-negative bacilli enter the cell and disrupt its ability to replicate.
Gram-negative bacilli release endotoxins that cause cell injury and increased capillary permeabilityExplanation: Gram-negative bacilli release endotoxins that cause cell injury and increased capillary permeability. Certain bacteria excrete elaborate exotoxins that interfere with cellular production of ATP. Gram-negative bacilli do not disrupt a cell's ability to replicate. Many Gram-negative bacilli cause harm to cells
Which assessment supports the finding of lead toxicity? Hemoglobin 9 g/dL (90 g/L) Heart rate 70 beats/min Hematocrit 40% Blood pressure 140/90 mm Hg
Hemoglobin 9 g/dL (90 g/L) Explanation: Anemia is a cardinal sign of lead toxicity. Lead competes with the enzymes required for hemoglobin synthesis and with the membrane-associated enzymes that prevent hemolysis of red blood cells. The other findings are not necessarily found in lead toxicity.
A 7-year-old boy is admitted to the hospital with a suspected diagnosis of lead toxicity. Which assessment finding is most congruent with the client's diagnosis? Hemoglobin 9.9 g/dL (99 g/L) Decreased deep tendon reflexes White blood cells (WBC) 11,000/mm3 (11.0 x 109/L) Diffuse muscle pain
Hemoglobin 9.9 g/dL (99 g/L) Explanation: Anemia is the cardinal sign of lead toxicity. Neither muscle pain, decreased deep tendon reflexes nor changes in WBC levels are associated with lead toxicity.
Select the statement that best describes apoptosis. The release of products of cell death is uncontrolled. Highly selective in eliminating injured or aged cells Unregulated by enzymatic digestion of cell components Responsible for initiating an inflammatory response
Highly selective in eliminating injured or aged cells Explanation: Apoptosis is a highly selective process that eliminates injured and aged cells in a manner that maintains the integrity of the plasma membrane and does not initiate inflammation. All the other options describe the occurrences of necrosis.
Which pathophysiologic process is most likely to result in metastatic calcification? Benign prostatic hyperplasia Impaired glycogen metabolism Hyperparathyroidism Liver cirrhosis
Hyperparathyroidism Explanation: Metastatic calcification is a result of markedly increased serum calcium levels. Because the parathyroid gland is responsible for the regulation of serum calcium levels, hyperparathyroidism creates a risk for hypercalcemia and consequent metastatic calcification. Benign prostatic hyperplasia, cirrhosis, and impaired glycogen metabolism are not implicated in cases of metastatic calcification.
Metastatic calcification takes place in normal tissues as the result of increased serum calcium levels (hypercalcemia). Anything that increases the serum calcium level can lead to calcification in inappropriate places such as the lung, renal tubules, and blood vessels. What are the major causes of hypercalcemia? Hyperparathyroidism and immobilization Hypoparathyroidism and vitamin D intoxication Diabetes mellitus and Paget disease Immobilization and hypoparathyroidism
Hyperparathyroidism and immobilization Explanation: Metastatic calcification occurs in normal tissues as the result of increased serum calcium levels (hypercalcemia). Almost any condition that increases the serum calcium level can lead to calcification in inappropriate sites such as the lung, renal tubules, and blood vessels. The major causes of hypercalcemia are hyperparathyroidism, either primary or secondary to phosphate retention in renal failure; increased mobilization of calcium from bone as in Paget disease, cancer with metastatic bone lesions, or immobilization; and vitamin D intoxication. Diabetes mellitus and hypoparathyroidism do not cause hypercalcemia; therefore, they cannot be a cause of metastatic calcification.
The nurse is conducting a physical assessment of a homeless man during a night when the wind chill factor is -10°F (-23°C). When assessing the man's fingers and toes for frostbite, the nurse looks for which type of cellular injury? Chemical Mechanical Hypoxic Endogenous
Hypoxic Explanation: Exposure to cold increases blood viscosity and induces vasoconstriction by direct action on blood vessels and through reflex activity of the sympathetic nervous system. The resultant decrease in blood flow may lead to hypoxic tissue injury, depending on the degree and duration of cold exposure.
A client with diabetes and severe peripheral vascular disease has developed signs of dry gangrene on the great toe of one foot. The client asks, "How this can happen?" Which pathophysiologic process should the nurse explain to this client? Metaplastic cellular changes in your toe. Inappropriate activation of apoptosis, which means death of your cells. Impaired arterial blood supply to your toe. Bacterial invasion into the foot and toe.
Impaired arterial blood supply to your toe. Explanation: Dry gangrene is often a result of impaired arterial blood supply to the extremities. A bacterial etiology is more common in wet gangrene, whereas neither metaplasia nor activation of apoptosis is implicated in cases of dry gangrene.
A client has been exposed to ultraviolet (UV) radiation. Which effect from the exposure is the nurse's primary concern? Severe decrease in sebaceous secretions Increased risk of cancer Increase in epidermal wrinkling Second-degree sunburn
Increased risk of cancer Explanation: UV radiation contains increasingly energetic rays that are powerful enough to disrupt intracellular bonds and increase the serious risk of skin cancers. Sunburn, increased wrinkles, and decreased lubrication are less serious in nature.
Despite the low levels of radiation used in contemporary radiologic imaging, a radiology technician wants to minimize personal exposure to ionizing radiation. What is the primary rationale for the technician's precautions about radiation exposure? Results in the accumulation of endogenous waste products in the cytoplasm Decreases the action potential of rapidly dividing cells Interferes with DNA synthesis and mitosis Stimulates pathologic cell hypertrophy and hyperplasia
Interferes with DNA synthesis and mitosisExplanation:Radiation has a damaging effect on DNA synthesis and mitosis, a process that is especially harmful to rapidly dividing cells. Radiation does not directly influence the action potential of cells or the accumulation of endogenous waste products. Cell changes such as hypertrophy or hyperplasia may result from radiation exposure, but such changes are secondary to interference with DNA synthesis and mitosis.
Which statement is true in relation to lead exposure? Increased calcium levels increase the risk of lead poisoning. Lead is absorbed through the skin. Increased iron increases the risk of lead poisoning. Lead is absorbed through the gastrointestinal tract or the lungs.
Lead is absorbed through the gastrointestinal tract or the lungs. Explanation: Lead is absorbed through the gastrointestinal tract and the lungs. It is not absorbed through the skin. Decreased calcium and iron increase the risk of lead poisoning.
Intracellular buildup of substances that can be either normal or toxic occurs in which area of the cell? Protein DNA Cell wall Lysosome
Lysosome Explanation: Intracellular accumulations represent the buildup of substances that cells cannot immediately use or eliminate. The substances may accumulate in the cytoplasm and frequently in the lysosomes.
A public health nurse is conducting a wellness seminar in which a participant has asked how to minimize the potentially harmful effects of free radicals. What should the nurse recommend? Make dietary changes and limit UV exposure. Monitor blood cholesterol levels and get sufficient sleep each night. Exercise regularly and take acetylsalicylic acid (ASA) 81 mg daily. Monitor blood glucose levels regularly and avoid tobacco use.
Make dietary changes and limit UV exposure. Explanation: The harmful effects of free radicals can be partially mitigated by increasing intake of foods known to be antioxidants. UV radiation causes oxidative damage, so limiting exposure prevents damage. ASA has no known effect on oxidative stress. All of the other listed actions are congruent with health but none directly addresses the effects of oxidative stress.
A worker in a warehouse is trying to have children but think he or she has handled "mercury" while cleaning equipment. Which statement by the occupational nurse is most appropriate at this time? Most mercury toxicity involves central nervous system changes. Infertility is caused by too much mercury exposure. You should have all the mercury fillings in your teeth changed to newer products. Usually mercury toxicity appears as skin rashes and lesions.
Most mercury toxicity involves central nervous system changes. Explanation:Mercury is toxic in four forms: mercury vapor, inorganic divalent mercury, methyl mercury, and ethyl mercury. Depending on the form of mercury exposure, toxicity involving the central nervous system and kidney can occur, not the dermal layers of the skin. In the case of dental fillings, the concern involves mercury vapor being released into the mouth. However, the amount of mercury vapor released from fillings is very small.
Which change exemplifies physiologic hypertrophy? Muscle mass increase with exercise Cell size increase with hypoxia Heart size increase in hypertension Lung size increase in emphysema
Muscle mass increase with exercise Explanation: Hypertrophy that occurs as the result of normal physiologic conditions is seen as muscle mass increases with exercise. Heart size increase in hypertension is an example of pathologic increase, as is lung size increase in emphysema and cell increase with hypoxia.
What happens as a cell's workload declines? Select all that apply. Oxygen consumption decreases. Protein synthesis decreases. Insulin levels increase. Cell size decreases. Energy expenditure increases.
Oxygen consumption decreases. Protein synthesis decreases. Cell size decreases. Explanation: As the cell's workload declines, oxygen consumption decreases, protein synthesis decreases, and cell size decreases. Insulin levels do not increase, and energy expenditure would decrease.
Mechanical forces that produce tissue trauma would be classified as which type of cellular injury? Physical agent Biologic agents Nutritional factors Chemical agent
Physical agent Explanation: Cell injury can be caused by a number of agents, including physical agents, chemicals, biologic agents, and nutritional factors. Among the physical agents that generate cell injury are mechanical forces that produce tissue trauma, extremes of temperature, electricity, radiation, and nutritional disorders. Chemical agents can cause cell injury through several mechanisms: they can block enzymatic pathways, cause coagulation of tissues, or disrupt the osmotic or ionic balance of the cell. Biologic agents differ from other injurious agents in that they are able to replicate and continue to produce injury. Among the nutritional factors that contribute to cell injury are excesses and deficiencies of nutrients, vitamins, and minerals.
A 68-year-old male client with aortic stenosis secondary to calcification of the aortic valve is receiving care. Which statement best captures an aspect of this client's condition? The client has possibly exhibited phosphate retention leading to calcium deposits. The client has possibly undergone damage as a result of calcification following cellular injury. Paget disease, cancer with metastases, or excess vitamin D may have been contributors. Increased calcium intake over time may have contributed to the problem.
The client has possibly undergone damage as a result of calcification following cellular injury. Explanation: Dystrophic calcification is a result of deposition of calcium following cellular injury, such as that which commonly occurs in heart valves. The other options refer to phenomenon associated with metastatic calcification and the associated increases in serum calcium levels.
A nurse is teaching a class on health promotion and includes information about the risk from ultraviolet radiation. Which concepts should be included in this class? Select all that apply. Ultraviolet radiation increases the risk of skin cancer. Ultraviolet radiation is only a problem in the summer months near the beach. Ultraviolet radiation damages DNA. Ultraviolet radiation, in small doses, poses no risk of skin cancer. Ultraviolet radiation does not pose a risk if it's cloudy or overcast outside.
Ultraviolet radiation increases the risk of skin cancer. Ultraviolet radiation damages DNA. Explanation: Ultraviolet radiation increases the risk of skin cancer and damages DNA. It is a concern year-round. Eighty percent of the sun's UV rays are able to pass through the clouds and fog. They block most UVB rays but won't block out UVA rays, which penetrate deep into the skin.
Which condition is an example of physiologic hyperplasia? Skin warts Endometrial hyperplasia Uterine enlargement in pregnancy Benign prostatic hyperplasia
Uterine enlargement in pregnancyExplanation:Two common types of physiologic hyperplasia are hormonal and compensatory. Breast and uterine enlargements during pregnancy are examples of a physiologic hyperplasia. The other examples are nonphysiologic hyperplasia.
A home health nurse is making a visit to a family with an 8-month-old infant with severe motor deterioration. The physician has diagnosed the infant with Tay-Sachs disease. The parents are asking the nurse why this happened. The nurse will base her answer knowing the root cause of Tay-Sachs is: high exposure to lead in the home environment. an enzyme defect causing abnormal lipid accumulation in the brain. an increase in bilirubin retention leading to destruction of RBCs. hypoxia caused by placing the infant on his or her abdomen during sleep.
an enzyme defect causing abnormal lipid accumulation in the brain. Explanation: Tay-Sachs disease is a genetic disorder resulting from an enzyme defect that results in abnormal lipid accumulation in the brain and other tissues. Lead exposure, hypoxia, and bilirubin retention is not associated with Tay-Sachs disease.
When confronted with a decrease in work demands or adverse environmental conditions, most cells are able to revert to a smaller size and a lower, more efficient level of functioning that is compatible with survival. This decrease in cell size is known as: hyperplasia. atrophy. metaplasia. hypertrophy. dysplasia.
atrophy. Explanation: When confronted with a decrease in work demands or adverse environmental conditions, most cells are able to revert to a smaller size and a lower and more efficient level of functioning that is compatible with survival. This decrease in cell size is called atrophy. Hypertrophy, metaplasia, and hyperplasia are all cellular adaptations that result in greater number or size. Dysplasia is a loss of cellular organization.
The nurse in an infectious-disease clinic will primarily treat injuries to tissues and cells caused by: oncogenic agents. biologic agents. calcification. chemical agents.
biologic agents.Explanation:Injury from biologic agents derives from bacterial and viral infections. The injuries differ from the other forms because they are able to replicate and can continue to produce their injurious effects. The etiology of infections does not normally include oncogenic agents, chemical agents, or calcifications.
The student is reviewing the aging process. One group of theories of aging involves the shortening of telomeres until a critical minimal length is attained and then senescence ensues. These theories are known as: evolutionary theories. cellular theories. molecular theories. systems-level theories.
cellular theories. Explanation: There are a number of cellular theories of senescence that are under investigation, including those that focus on telomere shortening.
The practitioner examines his client's foot and observes the great toe to be black and dry. The practitioner explains to the client that the dead tissue is caused by: dry gangrene. caseous necrosis. liquefaction necrosis. gas gangrene.
dry gangrene.Explanation:The term gangrene is applied when a considerable mass of tissue undergoes necrosis. Gangrene may be classified as dry or moist. In dry gangrene, the part becomes dry and shrinks, and its color changes to dark brown or black. Dry gangrene usually results from interference with arterial blood supply to a part. Liquefaction necrosis occurs when some of the cells die but their catalytic enzymes are not destroyed. An example of liquefaction necrosis is the softening of the center of an abscess with discharge of its contents. Characteristics of gas gangrene are bubbles of hydrogen sulfide gas in the muscle. Gas gangrene is prone to occur in trauma and compound fractures in which dirt and debris are embedded. Caseous necrosis is a distinctive form of coagulation necrosis in which the dead cells persist indefinitely as soft, cheese-like debris. It is most commonly found in the center of tuberculosis granulomas, or tubercles, and is thought to result from immune mechanisms.
When performing an assessment on a school-aged child, the nurse notes that the mucous membranes along the gum margins have a noticeable blue-colored line. At this point, the nurse should ask the parents about possible: congenital heart problems. liver problems as an infant. exposure to lead. second-hand smoke exposure.
exposure to lead. Explanation: The formation of a blue-colored line along the margins of the gum is one of the diagnostic features of lead poisoning. Liver problems are usually displayed as jaundice (yellowing of the skin/sclera). Congenital heart problems may exhibit cyanosis, but this would not be just in the gum margins. Second-hand smoke exposure may cause accumulation in the lungs.
In a genetic disorder called xeroderma pigmentosum, an enzyme needed to repair sunlight-induced DNA damage is lacking. This autosomal recessive disorder is characterized by: white, scaly patches of skin that appear on black people after they have a sunburn. extreme photosensitivity and a greatly increased risk of skin cancer in skin that has been exposed to the sun. photosensitivity and a decreased risk of skin cancer in skin that has been exposed to the sun. patches of pink, leathery pigmentation that replace normal skin after a sunburn.
extreme photosensitivity and a greatly increased risk of skin cancer in skin that has been exposed to the sun.Explanation:In a genetic disorder called xeroderma pigmentosum, an enzyme needed to repair sunlight-induced DNA damage is lacking. This autosomal recessive disorder is characterized by extreme photosensitivity and a 2000-fold increased risk of skin cancer in sun-exposed skin. Exposure to sun causes the skin to toughen and become leathery feeling, but not in patches of pink pigmented skin. Vitiligo is a benign acquired skin disease of unknown cause, consisting of irregular patches of various sizes totally lacking in pigment and often having hyperpigmented borders. It can appear in the skin of any race and is not scaly. Photosensitivity is a sign of xeroderma pigmentosum, but this disease increases, not decreases, the person's risk of skin cancer.
A client has developed heart failure. The doctor reviews the client's chest x-ray and notes that the heart has enlarged. The changes in the size and shape of the heart are the result of: atrophy. hypertrophy. hypoplasia. hyperplasia.
hypertrophy. Explanation: Cells adapt to changes in their environment and in their work demands by changing their size, number, and characteristics. An increase in work results in cells undergoing hypertrophy and increasing in size. Hyperplasia is an increase in the number of cells in an organ or tissue. A decrease in work demands or adverse environmental conditions can cause the cells to atrophy, or reduce in size. Hypoplasia is underdevelopment or incomplete development of a tissue or an organ.
The nurse explains to the hypertensive client that the increased workload required to pump blood against an elevated arterial pressure results in a progressive increase in left ventricular muscle mass. This is an example of: hyperplasia. metaplasia. hypertrophy. dysplasia.
hypertrophy. Explanation: In pressure overload, as occurs with hypertension, the muscle cells hypertrophy to increase the amount of functioning tissue.
The radiologist is reviewing potential types of radiation therapy for a client. Which type of radiation directly breaks down chemical bonds in a cell? sunlight radiation ionizing radiation ultraviolet radiation non-ionizing radiation
ionizing radiation Explanation: Ionizing radiation affects cells by causing ionization of molecules and atoms in the cell by directly hitting the target molecules of the cell and/or by producing free radicals that interact with critical cell components. Non-ionizing radiation exerts its effects on the cell by causing a vibration and rotation of atoms and molecules. Sunlight is a form of ultraviolet radiation that induces skin damage by reactive oxygen species and by damage to the melanin-producing processes in the skin.
