Cell injury

Cell injury US Medical PG Question 1: Which transport mechanism is primarily responsible for calcium reabsorption in the proximal tubule?

• A. Paracellular transport (Correct Answer)
• B. Facilitated diffusion
• C. Active transport
• D. Antiport with sodium

Cell injury Explanation: ***Paracellular transport*** - In the **proximal tubule**, approximately 60-70% of filtered calcium is reabsorbed primarily through the **paracellular pathway**, driven by the electrochemical gradient and solvent drag. - This transport occurs between cells, moving through the **tight junctions**, and is passive, following the reabsorption of water. *Facilitated diffusion* - While a type of passive transport, **facilitated diffusion** typically involves membrane proteins and occurs across the cell membrane, not primarily between cells in the proximal tubule for calcium. - This mechanism is prominent for calcium reabsorption in other nephron segments like the **distal convoluted tubule** via **TRPV5/6 channels**, but not the main route in the proximal tubule. *Active transport* - **Active transport** of calcium, mainly via **calcium ATPase** and the **Na+/Ca2+ exchanger**, occurs across the luminal and basolateral membranes, respectively, in specific nephron segments. - However, in the **proximal tubule**, the bulk of calcium reabsorption is passive and paracellular, not ATP-dependent active transport across cell membranes. *Antiport with sodium* - The **Na+/Ca2+ exchanger (NCX)** is an antiport mechanism that plays a crucial role in extruding calcium from the cell into the interstitium, particularly in the basolateral membrane of the distal tubule. - However, it is not the primary mechanism for overall tubular reabsorption of calcium in the **proximal tubule**, where paracellular movement dominates.

Cell injury US Medical PG Question 2: A 52-year-old man is brought to the emergency department by ambulance after a motor vehicle accident. He was an unrestrained passenger who was ejected from the vehicle. On presentation, he is found to be actively bleeding from numerous wounds. His blood pressure is 76/42 mmHg and pulse is 152/min. Attempts at resuscitation fail, and he dies 25 minutes later. Autopsy shows blood in the peritoneal cavity, and histology of the kidney reveals swelling of the proximal convoluted tubule epithelial cells. Which of the following is most likely the mechanism underlying the renal cell findings?

• A. Decreased activity of caspase 7
• B. Increased activity of caspase 9
• C. Increased function of the Na+/K+-ATPase
• D. Increased activity of caspase 8
• E. Decreased function of the Na+/K+-ATPase (Correct Answer)

Cell injury Explanation: ***Decreased function of the Na+/K+-ATPase*** - The patient experienced **hypovolemic shock** due to severe blood loss, leading to a significant drop in blood pressure and organ perfusion. This results in **ischemia** of the renal cells. - **Ischemic injury** impairs ATP production, which is essential for the function of the **Na+/K+-ATPase pump**. Failure of this pump leads to intracellular accumulation of sodium and water, causing **cellular swelling**, particularly noticeable in the proximal convoluted tubules. *Decreased activity of caspase 7* - **Caspases**, including caspase 7, are involved in **apoptosis** (programmed cell death), which involves cell shrinkage and fragmentation, not the swelling observed here. - Decreased caspase activity would generally *reduce* apoptosis, which is not the primary mechanism of acute cell injury in shock. *Increased activity of caspase 9* - Increased activity of **caspase 9** is indicative of the **intrinsic apoptotic pathway**, typically initiated by mitochondrial damage. - While prolonged ischemia can eventually lead to apoptotic changes, the acute finding of **cellular swelling** points more directly to immediate membrane pump dysfunction due to ATP depletion. *Increased function of the Na+/K+-ATPase* - **Increased function** of the Na+/K+-ATPase would actively pump sodium out of the cell and potassium in, *preventing* intracellular swelling. - This option contradicts the observed finding of proximal convoluted tubule epithelial cell swelling, which is characteristic of acute cellular injury due to pump failure. *Increased activity of caspase 8* - **Caspase 8** is a key initiator caspase in the **extrinsic apoptotic pathway**, often triggered by death receptor signaling. - Similar to caspase 9, increased caspase 8 activity would lead to apoptosis, characterized by cell shrinkage, not the **cellular swelling** seen in acute ischemic injury.

Cell injury US Medical PG Question 3: An investigator is examining tissue samples from various muscle tissue throughout the body. She notices that biopsies collected from a specific site have a high concentration of sarcoplasmic reticulum, mitochondria, and myoglobin; they also stain poorly for ATPase. Additionally, the cell surface membranes of the myocytes in the specimen lack voltage-gated calcium channels. These myocytes are found in the greatest concentration at which of the following sites?

• A. Ventricular myocardium
• B. Tunica media
• C. Lateral rectus muscle
• D. Glandular myoepithelium
• E. Semispinalis muscle (Correct Answer)

Cell injury Explanation: ***Semispinalis muscle*** - The described characteristics—**high concentration of sarcoplasmic reticulum, mitochondria, and myoglobin** with **poor ATPase staining**—are hallmarks of **Type I (slow-twitch oxidative) skeletal muscle fibers**. - Postural muscles like the **semispinalis** (part of the erector spinae group) are predominantly composed of Type I fibers adapted for sustained, aerobic contraction to maintain posture. - These fibers appear **red** due to high myoglobin content, have abundant mitochondria for aerobic metabolism, and stain **poorly for ATPase** (distinguishing them from Type II fast-twitch fibers). - While all skeletal muscle does possess voltage-gated calcium channels for excitation-contraction coupling, the overall profile best matches slow-twitch postural muscles. *Ventricular myocardium* - While cardiac muscle has high mitochondria, myoglobin, and sarcoplasmic reticulum, it **does possess L-type voltage-gated calcium channels** on the sarcolemma, which are essential for cardiac excitation-contraction coupling. - Cardiac muscle relies on **both** extracellular Ca²⁺ influx through these channels and calcium-induced calcium release from the SR. - Cardiac muscle typically stains **strongly for ATPase**, not poorly. *Tunica media* - Composed of **vascular smooth muscle** with poorly developed sarcoplasmic reticulum and relatively few mitochondria compared to skeletal or cardiac muscle. - Smooth muscle relies heavily on **extracellular calcium influx** and the calmodulin pathway for contraction. - Not characterized by high myoglobin content. *Lateral rectus muscle* - This extraocular muscle contains predominantly **Type IIb fast-twitch glycolytic fibers** adapted for rapid, precise eye movements. - These fibers have **low myoglobin** (white muscle), fewer mitochondria, and stain **strongly for ATPase**. - Opposite profile from the described tissue. *Glandular myoepithelium* - Myoepithelial cells are specialized contractile cells in secretory glands with minimal sarcoplasmic reticulum and mitochondria. - Function is brief contraction for secretion expulsion, not sustained aerobic work. - Do not exhibit the high oxidative capacity described.

Cell injury US Medical PG Question 4: A 72-year-old man presents to the emergency department after a fall. The patient was found lying down on the floor in his room in his retirement community. The patient has a past medical history of Alzheimer dementia and a prosthetic valve. His current medications include donepezil and warfarin. His temperature is 97.7°F (36.5°C), blood pressure is 85/50 mmHg, pulse is 160/min, respirations are 13/min, and oxygen saturation is 97% on room air. The patient is started on IV fluids and a type and screen is performed. Laboratory values are ordered as seen below. Hemoglobin: 13 g/dL Hematocrit: 39% Leukocyte count: 5,500 cells/mm^3 with normal differential Platelet count: 225,000/mm^3 INR: 2.5 AST: 10 U/L ALT: 12 U/L A chest radiograph and EKG are performed and are within normal limits. A full physical exam is within normal limits. The patient's vitals are repeated. His temperature is 99.5°F (37.5°C), blood pressure is 110/70 mmHg, pulse is 90/min, respirations are 10/min, and oxygen saturation is 98% on room air. Which of the following is the best next step in management?

• A. CT scan (Correct Answer)
• B. Urgent blood transfusion
• C. Fresh frozen plasma
• D. Exploratory laparoscopy
• E. Exploratory laparotomy

Cell injury Explanation: ***CT scan*** - A patient with a **prosthetic valve** on **warfarin** and a fall is at high risk for **intracranial hemorrhage**, even without focal neurological deficits. - While initial vitals improved after IV fluids, the mechanism of injury (fall) and medication profile warrant a **CT scan** of the head to rule out serious internal injury, especially given the history of dementia which might mask symptoms. *Urgent blood transfusion* - The patient's **hemoglobin (13 g/dL)** and **hematocrit (39%)** are within normal limits, indicating no acute need for blood transfusion due to hemorrhage. - Transfusions are typically reserved for patients with significant blood loss or severe symptomatic anemia. *Fresh frozen plasma* - The patient's **INR of 2.5** is within the therapeutic range for a patient with a prosthetic valve on warfarin. - There is no evidence of active bleeding or supratherapeutic anticoagulation that would necessitate the administration of **fresh frozen plasma (FFP)** to reverse anticoagulation. *Exploratory laparoscopy* - There are no clinical signs or symptoms, such as abdominal pain, distension, or evidence of intra-abdominal bleeding (e.g., declining hemoglobin, peritoneal signs), to suggest an indication for an **exploratory laparoscopy**. - The patient's physical exam was described as normal. *Exploratory laparotomy* - Similar to laparoscopy, there is no clinical evidence of acute abdominal injury or hemorrhage, which would necessitate an **exploratory laparotomy**. - This invasive procedure is reserved for cases with strong suspicion of significant intra-abdominal pathology or trauma.

Cell injury US Medical PG Question 5: A 31-year-old woman scrapes her finger on an exposed nail and sustains a minor laceration. Five minutes later, her finger is red, swollen, and painful. She has no past medical history and does not take any medications. She drinks socially with her friends and does not smoke. The inflammatory cell type most likely to be prominent in this patient's finger has which of the following characteristics?

• A. Segmented nuclei (Correct Answer)
• B. Dramatically expanded endoplasmic reticulum
• C. Large cell with amoeboid movement
• D. Multiple peripheral processes
• E. Dark histamine containing granules

Cell injury Explanation: ***Segmented nuclei*** - This scenario describes **acute inflammation** following a minor injury, with classic signs of **redness, swelling, and pain** within minutes. - **Neutrophils** are the primary inflammatory cells in acute inflammation and are characterized by their **segmented (multi-lobed) nuclei.** *Dramatically expanded endoplasmic reticulum* - An expanded endoplasmic reticulum is characteristic of cells highly active in protein synthesis and secretion, such as **plasma cells** producing antibodies. - Plasma cells are typically involved in **chronic inflammation** and adaptive immune responses, not rapid acute inflammation. *Large cell with amoeboid movement* - This describes **macrophages**, which are phagocytic cells important in both acute and chronic inflammation, and in cleaning up debris. - While macrophages are present, **neutrophils** are the predominant early responders in acute bacterial infections and tissue injury. *Multiple peripheral processes* - This description is characteristic of **dendritic cells**, which are antigen-presenting cells that initiate adaptive immune responses. - Dendritic cells play a role in linking innate and adaptive immunity but are not the primary inflammatory cell type in the immediate acute response. *Dark histamine containing granules* - This description applies to **mast cells** and **basophils**, which release histamine and other mediators in allergic reactions and acute inflammation. - While mast cells are involved in the immediate response by releasing mediators, **neutrophils** are the main cellular players migrating to the site of injury.

Cell injury US Medical PG Question 6: A 56-year-old man presents to the emergency room with severe substernal chest pain associated with a 2-hour history of breathlessness and sweating. An electrocardiogram shows an ST-segment elevation myocardial infarction. Cardiac enzyme levels confirm a diagnosis of acute myocardial infarction. The patient is rushed to the catheter lab for angioplasty with stenting. The patient complains of recurrent chest pain in the ICU 56 hours post-angioplasty. Which of the following enzymes facilitates the patient’s diagnosis based on his current symptoms?

• A. Creatine kinase (CK)-MB (Correct Answer)
• B. Creatine kinase – MM
• C. Troponin T
• D. Troponin I
• E. Lactate dehydrogenase (LDH)

Cell injury Explanation: ***Creatine kinase (CK)-MB*** - **CK-MB** is elevated in myocardial infarction, rising within 4-6 hours, peaking at 24 hours, and **returning to baseline within 48-72 hours** after the initial event. - At **56 hours post-angioplasty**, CK-MB levels should have normalized from the initial MI, making a **new elevation highly specific** for reinfarction or new myocardial injury. - This makes CK-MB particularly useful for detecting **early reinfarction** when the timing allows it to have cleared from the initial event. - **Clinical pearl**: This represents classical teaching about cardiac enzyme kinetics, though modern practice increasingly uses serial troponin measurements with delta criteria. *Creatine kinase – MM* - **CK-MM** is the predominant isoform of creatine kinase found in **skeletal muscle**, not cardiac muscle. - While total CK (which includes CK-MM) increases in MI, CK-MM elevation is **not specific to cardiac injury** and can be elevated from skeletal muscle damage or other causes. - Its lack of cardiac specificity makes it a **poor indicator for myocardial reinfarction**. *Troponin T* - **Troponin T** is highly sensitive and specific for myocardial injury, but levels remain **elevated for 7-10 days** following an acute MI. - At 56 hours post-angioplasty, troponin T would **still be elevated from the initial MI**, making it difficult to distinguish baseline elevation from a new acute event. - While a **significant rise (>20%) from the previous value** can indicate reinfarction, the persistently elevated baseline makes interpretation more complex compared to CK-MB which should have normalized. *Troponin I* - **Troponin I** remains elevated for **5-7 days** following an acute MI, similar to troponin T. - At 56 hours post-initial MI, troponin I levels would **still be elevated**, making it challenging to clearly identify a new ischemic event without comparing to prior values. - Though troponins are the **gold standard for MI diagnosis**, their prolonged elevation window makes CK-MB more straightforward for detecting reinfarction at this specific timepoint (when CK-MB should have returned to baseline). *Lactate dehydrogenase (LDH)* - **LDH** elevation occurs later in MI (24-48 hours after onset) and remains elevated for **10-14 days**. - Due to its **delayed rise and prolonged elevation**, LDH is not useful for diagnosing acute reinfarction in the early post-MI period. - LDH lacks the rapid kinetics and cardiac specificity needed for timely diagnosis of new myocardial injury.

Cell injury US Medical PG Question 7: A 73-year-old man with coronary artery disease and hypertension is brought to the emergency department by ambulance 90 minutes after the acute onset of substernal chest pain and dyspnea. He has smoked 2 packs of cigarettes daily for 52 years. Shortly after arriving at the hospital, he loses consciousness and is pulseless. Despite attempts at cardiopulmonary resuscitation, he dies. Examination of the heart at autopsy shows complete occlusion of the left anterior descending artery with a red thrombus overlying a necrotic plaque. Which of the following pathophysiologic mechanisms is most likely responsible for this patient's acute coronary condition?

• A. Influx of lipids into the endothelium
• B. Secretion of matrix metalloproteinases (Correct Answer)
• C. Release of platelet-derived growth factor
• D. Type III collagen deposition
• E. Proliferation of smooth muscle cells

Cell injury Explanation: ***Secretion of matrix metalloproteinases*** - **Matrix metalloproteinases (MMPs)** degrade the **extracellular matrix** within the fibrous cap of an atherosclerotic plaque, leading to its **destabilization and rupture**. - Plaque rupture then exposes the highly thrombogenic lipid core, initiating thrombus formation and acute coronary events like the **red thrombus** seen in the **left anterior descending artery (LAD)**. *Influx of lipids into the endothelium* - This process is characteristic of the **initial stages of atherosclerosis**, leading to **fatty streak formation**, not the acute plaque rupture and thrombosis described. - While essential for plaque development, lipid influx alone does not directly explain aggressive plaque rupture and acute thrombus formation. *Release of platelet-derived growth factor* - **Platelet-derived growth factor (PDGF)** is primarily involved in **smooth muscle cell proliferation** and migration, contributing to plaque growth and thickening. - Its role is more chronic and proliferative, not immediate plaque destabilization and rupture leading to acute thrombosis. *Type III collagen deposition* - **Type III collagen** is characteristic of early, developing atherosclerotic plaques and granulation tissue, contributing to plaque stability. - Plaque vulnerability associated with rupture involves a **thin fibrous cap** with reduced **collagen content**, often due to increased collagen degradation. *Proliferation of smooth muscle cells* - **Smooth muscle cell proliferation** occurs during chronic atherosclerosis, contributing to the **fibrous cap formation** and overall plaque stability. - In the context of acute plaque rupture, it is the *erosion* of the fibrous cap, often due to degradation, rather than proliferation, that is the immediate cause.

Cell injury US Medical PG Question 8: A 42-year-old man with systolic heart failure secondary to amyloidosis undergoes heart transplantation. The donor heart is obtained from a 17-year-old boy who died in a motor vehicle collision. Examination of the donor heart during the procedure shows a flat, yellow-white discoloration with an irregular border on the luminal surface of the aorta. A biopsy of this lesion is most likely to show which of the following?

• A. Apoptotic smooth muscle cells
• B. Necrotic cell debris
• C. Proteoglycan accumulation
• D. Collagen deposition
• E. Lipoprotein-laden macrophages (Correct Answer)

Cell injury Explanation: ***Lipoprotein-laden macrophages*** - The description of a flat, yellow-white discolored lesion with an irregular border on the luminal surface of the aorta in a 17-year-old is classic for a **fatty streak**, the earliest lesion of **atherosclerosis**. - Fatty streaks are histologically characterized by the accumulation of **macrophages that have ingested oxidized lipoproteins**, appearing as foam cells within the intima. *Apoptotic smooth muscle cells* - While apoptosis of various cell types, including smooth muscle cells, can occur in advanced atherosclerotic lesions, it is not the primary or defining feature of an early **fatty streak**. - **Apoptosis** contributes to the necrotic core formation in later stages of plaque development, not the initial yellow-white discoloration of a fatty streak. *Necrotic cell debris* - **Necrotic cell debris** is a prominent feature of more advanced, **complicated atherosclerotic plaques**, forming the necrotic core. - In a **fatty streak**, the cells are primarily viable foam cells, and significant necrosis is not yet present. *Proteoglycan accumulation* - **Proteoglycan accumulation** occurs in the arterial intima and is involved in the retention of lipoproteins, contributing to the development of atherosclerosis. - However, the immediate and most characteristic histological finding of the **yellow-white discoloration** in a fatty streak is the lipid-laden macrophage. *Collagen deposition* - **Collagen deposition** is a key feature of the fibrous cap in **advanced atherosclerotic plaques**, laid down by migrating smooth muscle cells. - It is not the primary histological characteristic of an early, flat, yellow-white **fatty streak**.

Cell injury US Medical PG Question 9: As part of a clinical research study, microscopic analysis of tissues obtained from surgical specimens is performed. Some of these tissues have microscopic findings of an increase in the size of numerous cells within the tissue with an increase in the amount of cytoplasm, but the nuclei are uniform in size. Which of the following processes shows such microscopic findings?

• A. Liver following partial resection
• B. Female breasts at puberty
• C. Ovaries following menopause
• D. Uterine myometrium in pregnancy (Correct Answer)
• E. Cervix with chronic inflammation

Cell injury Explanation: ***Uterine myometrium in pregnancy*** - During pregnancy, the uterine myometrial cells undergo significant **hypertrophy** (increase in cell size) in response to hormonal stimulation, primarily *estrogen* and *progesterone*. - This leads to a marked increase in the amount of **cytoplasm** and overall cell size, while maintaining relatively **uniform nuclei**, which precisely matches the microscopic findings described. - The smooth muscle cells can increase **10-40 fold** in size, making this the classic example of physiologic hypertrophy. - Note: Hyperplasia (increased cell number) also occurs but is less prominent; the microscopic findings described emphasize the hypertrophic changes. *Liver following partial resection* - The liver primarily undergoes **hyperplasia** (increase in cell number) to regenerate following partial resection. - While some hypertrophy occurs, the dominant microscopic finding is an increase in hepatocyte **number** through proliferation rather than a marked increase in individual cell size and cytoplasm as the primary feature. *Female breasts at puberty* - Breast development at puberty involves both **hyperplasia** of the glandular epithelium and ductal structures and **adipose tissue deposition**, driven by *estrogen* and *progesterone*. - The findings described (marked increase in cell size and cytoplasm with uniform nuclei) are more characteristic of the extreme cell hypertrophy seen in the gravid uterus rather than the mixed growth and differentiation patterns of pubertal breast development. *Ovaries following menopause* - Following menopause, the ovaries undergo **atrophy**, meaning a decrease in size and cellular activity due to declining hormonal production. - This process involves a **decrease in cell size** and number, which is the opposite of the microscopic findings described in the question. *Cervix with chronic inflammation* - Chronic inflammation in the cervix can cause various changes, including **squamous metaplasia** (transformation of columnar epithelium to squamous epithelium) or an influx of inflammatory cells. - While there might be some reactive cellular changes, it does not typically involve a widespread, uniform increase in cell size and cytoplasm within existing cells as described, but rather a change in cell type or infiltration by inflammatory cells.

Cell injury US Medical PG Question 10: A 54-year-old man comes to the physician because of a cough with blood-tinged sputum for 1 week. He also reports fever and a 5-kg (11 lb) weight loss during the past 2 months. Over the past year, he has had 4 episodes of sinusitis. Physical examination shows palpable nonblanching skin lesions over the hands and feet. Examination of the nasal cavity shows ulceration of the nasopharyngeal mucosa and a depressed nasal bridge. Oral examination shows a painful erythematous gingival enlargement that bleeds easily on contact. Which of the following is the most likely cause of the patient's symptoms?

• A. Metalloprotease enzyme deficiency
• B. Malignant myeloid cell proliferation
• C. Arteriovenous malformation
• D. Immune complex deposition
• E. Neutrophil-mediated damage (Correct Answer)

Cell injury Explanation: ***Neutrophil-mediated damage*** - The constellation of **sinusitis**, **pulmonary symptoms** (cough with blood-tinged sputum), **renal involvement** (indicated by systemic symptoms and often associated with microhematuria in this condition), and **skin lesions (palpable purpura)**, along with **nasal ulceration**, a **depressed nasal bridge**, and **gingival enlargement**, is highly characteristic of **Granulomatosis with Polyangiitis (GPA)**. - GPA is an **ANCA-associated vasculitis** characterized by **necrotizing granulomatous inflammation** and **vasculitis** of small to medium-sized vessels, primarily driven by **neutrophil activation** and subsequent tissue damage. *Metalloprotease enzyme deficiency* - This description commonly refers to conditions like **alpha-1 antitrypsin deficiency**, which primarily causes **emphysema** and liver disease, not the widespread vasculitic manifestations seen here. - It does not explain the diverse multi-organ involvement including skin, ENT, and likely renal symptoms. *Malignant myeloid cell proliferation* - This would suggest conditions like **leukemia** or **myelodysplastic syndromes**, which present with altered blood counts, fatigue, infections, and bleeding, but typically not this specific pattern of vasculitis and granulomatous inflammation. - While constitutional symptoms like weight loss can occur, the localized findings like depressed nasal bridge and gingival enlargement are not characteristic. *Arteriovenous malformation* - An **arteriovenous malformation (AVM)** is an abnormal connection between arteries and veins; depending on its location, it can cause bleeding (e.g., hemoptysis if pulmonary) or neurological symptoms if cerebral. - However, AVMs do not explain the systemic inflammatory symptoms, skin lesions, sinusitis, depressed nasal bridge, or gingival changes. *Immune complex deposition* - **Immune complex vasculitis** (e.g., IgA vasculitis, cryoglobulinemic vasculitis) often presents with palpable purpura and can affect kidneys and GI tract. - However, the prominent **granulomatous inflammation** causing **nasal ulceration** and **depressed nasal bridge**, and the specific type of **pulmonary-renal syndrome** seen in GPA, are more indicative of **ANCA-mediated neutrophil damage** rather than immune complex deposition.

Cell injury Flashcard 1 of 10

Question: Plasma membrane damage in irreversible cellular injury results entry of _____ ion into the cell

Answer: Ca2+

Cell injury Flashcard 2 of 10

Question: Which mechanism of cell death is an ATP-dependent programmed cell death? _____

Answer: Apoptosis

Cell injury Flashcard 3 of 10

Question: _____ membrane damage in irreversible cell injury results in hydrolytic enzymes leaking into the cytosol

Answer: Lysosome

Cell injury Flashcard 4 of 10

Question: What is the end result of irreversible cell injury?_____

Answer: Cell death

Cell injury Flashcard 5 of 10

Question: Apoptosis is characterized morphologically by cell _____ (size), chromatin condensation, and membrane blebbing

Answer: shrinkage

Cell injury Flashcard 6 of 10

Question: Fat necrosis of breast tissue presents as a painless _____ on physical exam

Answer: mass

Extra Information:   * Necrosis may be tender and painful, as well; "irregular breast mass" Watch Benign Breast Disorders [https://dashboard.sketchy.com/study/medical/courses/medical-pathophysiology/units/medical-pathophysiology-reproductive-gu/videos/medical-pathophysiology-reproductive-and-gu-breast-benign-breast-disorders?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical] https://onlinemeded.org/spa/inflammation-and-neoplasia/necrosis/acquire?ref=anki 

Cell injury Flashcard 7 of 10

Question: Niemann Pick disease may present with progressive _____

Answer: neurodegeneration

Extra Information:   https://onlinemeded.org/spa/metabolism?ref=anki 

Cell injury Flashcard 8 of 10

Question: Which layer of the cerebellum is most affected by global cerebral ischemia? _____

Answer: Purkinje layer

Extra Information:  Watch associated Bootcamp video [https://app.bootcamp.com/med-school/neurology/videos/ischemic-cerebrovascular-accidents?index=2] https://onlinemeded.org?ref=anki Atlas: 

Cell injury Flashcard 9 of 10

Question: Ionizing radiation results in the formation of double-stranded breaks in DNA and _____ which damage DNA

Answer: hydroxyl free radicals

Extra Information:   https://onlinemeded.org?ref=anki 

Cell injury Flashcard 10 of 10

Question: Photoaging results in gradual _____ of the epidermis, allowing the stratum corneum to become dessicated

Answer: thinning

Extra Information:  https://onlinemeded.org?ref=anki