Cell Injury: reversible vs irreversible

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Questions and Answers

What is the first type of alteration seen when a cell is injured?

Light microscopic changes
Ultrastructural changes
Biochemical alterations (correct)
Gross morphologic changes

Which sequence correctly represents the progression of changes seen in cell injury?

Gross morphologic changes → Biochemical alterations → Ultrastructural changes → Light microscopic changes
Biochemical alterations → Ultrastructural changes → Light microscopic changes → Gross morphologic changes (correct)
Ultrastructural changes → Biochemical alterations → Light microscopic changes → Gross morphologic changes
Light microscopic changes → Biochemical alterations → Gross morphologic changes → Ultrastructural changes

What is the definition of acute cell swelling?

A lethal injury causing cell lysis
An early, sub-lethal manifestation of cell damage characterized by increased cell size and volume due to water overload (correct)
A chronic degenerative process leading to cell atrophy
A sudden loss of cell membrane integrity due to enzymatic degradation

Which cells are highly vulnerable to hypoxia and cell swelling?

Cardiomyocytes, proximal renal tubule epithelium, hepatocytes, and neurons (B) Signup and view all the answers

What is the primary cause of acute cell swelling?

Loss of ionic and fluid homeostasis (B) Signup and view all the answers

Which of the following is NOT a potential cause of acute cell swelling

Excessive collagen deposition (C) Signup and view all the answers

What is the main mechanism behind acute cell swelling?

Failure of ATP-dependent ion pumps leading to Na+ and water influx (D) Signup and view all the answers

How does an organ affected by acute cell swelling typically appear grossly?

Swollen with rounded edges, increased pallor, and slightly heavy (“wet organ”) (B) Signup and view all the answers

What happens to the cut surface of an organ affected by acute cell swelling?

It bulges out and does not return to normal position (B) Signup and view all the answers

What is the key histologic feature of cellular swelling?

Enlarged cells with pale cytoplasm due to water uptake (B) Signup and view all the answers

What happens to the nucleus in cells undergoing acute cell swelling?

It remains in its normal position with no morphological changes (C) Signup and view all the answers

Which of the following is a plasma membrane alteration seen in cellular swelling?

Blebbing and loss of microvilli (A) Signup and view all the answers

What mitochondrial changes are observed in cellular swelling?

Mitochondrial swelling and the appearance of amorphous densities (A) Signup and view all the answers

What happens to the endoplasmic reticulum (ER) in cellular swelling?

It dilates, and ribosomes detach (D) Signup and view all the answers

What nuclear alterations are seen in cellular swelling?

Disaggregation of granular and fibrillar components (A) Signup and view all the answers

How does cellular swelling differ from hypertrophy?

Cellular swelling is due to increased water uptake, while hypertrophy is due to increased organelles and protein synthesis (A) Signup and view all the answers

What determines the prognosis of cellular swelling?

The number of affected cells and their functional importance (A) Signup and view all the answers

When is the prognosis for cellular swelling considered good?

When oxygen is restored before the "point of no return" (B) Signup and view all the answers

What happens if cellular swelling progresses to irreversible injury?

The affected cells undergo necrosis (B) Signup and view all the answers

Normally a fatty change may be preceded or accompanied by cell swelling

True (A) Signup and view all the answers

List all the major classes of lipids (discussed in class) that can accumulate in cells due to a fatty change (hint: 4)

Triglycerides, cholesterol/cholesterol esters, phospholipids, abnormal complexes of lipids and carbohydrates (lysosomal storage disease) Signup and view all the answers

What is the definition of fatty change?

A sub-lethal cell injury characterized by the accumulation of lipids within the cytoplasm (D) Signup and view all the answers

What is lipidosis?

The accumulation of triglycerides and other lipid metabolites within parenchymal cells (A) Signup and view all the answers

What organ is most commonly affected by lipidosis?

Liver Signup and view all the answers

What is the primary mechanism leading to fatty change in hepatocytes?

Impaired metabolism of fatty acids leading to accumulation of triglycerides (B) Signup and view all the answers

What are the (three) etiologic causes of fatty change?

Hypoxia, toxicity and metabolic disorders Signup and view all the answers

Which of the following is NOT a major mechanism contributing to hepatic lipidosis?

Increased synthesis of apoproteins (C) Signup and view all the answers

What is the typical gross appearance of a liver affected by fatty change?

Diffusely yellow, soft, and greasy, friable tissue (C) Signup and view all the answers

Which species is particularly prone to hepatic lipidosis due to pregnancy toxemia and ketosis?

Ruminants (B) Signup and view all the answers

In which of the following conditions is hepatic lipidosis commonly observed?

All of the above (D) Signup and view all the answers

What are the (three) etiologies of hepatic lipidosis?

Nutritional disorders, endocrine diseases and genetic disorders Signup and view all the answers

What is the characteristic histologic feature of fatty change in hepatocytes?

Large, well-delineated, lipid-filled vacuoles in the cytoplasm (A) Signup and view all the answers

What happens to the nucleus in hepatocytes undergoing fatty change?

It is displaced to the periphery of the cell by large lipid vacuoles (B) Signup and view all the answers

The prognosis of fatty change is irreversible and the hepatocytes die.

False (B) Signup and view all the answers

Which of the following morphological changes is a hallmark of irreversible cell injury?

Severe mitochondrial swelling and rupture (B) Signup and view all the answers

List the three morphological hallmarks of irreversible cell injury

Severe swelling of mitochondria, extensive damage to plasma membranes, and swelling of lysosomes Signup and view all the answers

What is the definition of necrosis?

Uncontrolled cell death caused by external factors, leading to inflammation (B) Signup and view all the answers

What is the primary difference between necrosis and apoptosis?

Necrosis involves inflammation, while apoptosis does not (C) Signup and view all the answers

Which of the following processes is responsible for the morphological features of necrosis?

Denaturation of proteins and enzymatic digestion of the cell (B) Signup and view all the answers

How can you describe the gross appearance of necrosis?

Multiple soft, friable, slightly depressed foci sharply demarcated from viable tissue Signup and view all the answers

What are the six types of oncotic necrosis?

Coagulative necrosis, caseous necrosis, liquefactive necrosis, gangrenous necrosis, fat necrosis and fibrinoid necrosis Signup and view all the answers

Which type of necrosis is commonly associated with ischemia and hypoxia?

Coagulative necrosis (A) Signup and view all the answers

Which organ is most susceptible to liquefactive necrosis?

Brain (B) Signup and view all the answers

What is the most common cause of gangrenous necrosis?

Ischemia, typically in the extremities (A) Signup and view all the answers

What is the difference between dry and wet gangrene?

Wet gangrene is characterized by bacterial infection and tissue liquefaction, while dry gangrene results from ischemia without infection (D) Signup and view all the answers

What is the characteristic appearance of caseous necrosis?

Cheese-like, friable, and crumbly appearance (dead WBC) (B) Signup and view all the answers

What are the three types of fat necrosis?

Enzymatic necrosis, traumatic necrosis of fat and necrosis of abdominal fat Signup and view all the answers

What condition is often associated with traumatic fat necrosis in cattle?

Recumbency leading to fat trauma at the sternum (B) Signup and view all the answers

What is the main histological feature of fibrinoid necrosis?

Eosinophilic fibrin-like deposits in vessel walls (A) Signup and view all the answers

Fibrinoid necrosis is most commonly associated with which condition?

Immune-mediated vasculitis (B) Signup and view all the answers

What is a defining feature of apoptosis?

Activation of initiator and executioner caspases (B) Signup and view all the answers

Which of the following are considered initiator caspases in apoptosis?

Caspase-8 and Caspase-9 (C) Signup and view all the answers

Which caspases act as executioners in apoptosis?

Caspase-3 and Caspase-6 (A) Signup and view all the answers

What is the major mechanism of the intrinsic pathway of apoptosis

Release of pro-apoptotic molecules from mitochondria (B) Signup and view all the answers

Which molecule is essential for apoptosis and is released from mitochondria to activate caspases?

Cytochrome c (A) Signup and view all the answers

The extrinsic pathway of apoptosis is initiated by:

Death receptor activation (D) Signup and view all the answers

What are the two main death receptors involved in the extrinsic pathway of apoptosis?

Fas (CD95) and TNF receptor 1 (TNFR1) (B) Signup and view all the answers

What protein binds to the Fas receptor to activate the extrinsic apoptosis pathway?

Fas ligand (FasL) (B) Signup and view all the answers

What cellular stress can lead to apoptosis due to protein misfolding?

ER stress (A) Signup and view all the answers

What is the consequence of excessive misfolded protein accumulation in the endoplasmic reticulum?

Apoptosis due to activation of the unfolded protein response (B) Signup and view all the answers

How are apoptotic cells removed from the body?

By macrophages recognizing phosphatidylserine on the apoptotic cell surface (B) Signup and view all the answers

What happens when apoptosis is defective (too little apoptosis)?

Increased risk of neoplasia (cancer) (B) Signup and view all the answers

What are the three disorders associated with increased apoptosis and excessive cell death?

Neurodegenerative disorder, ischemic injury and death of virus infected cells Signup and view all the answers

What are the other two types of cell death?

Necroptosis (programmed necrosis) and pyroptosis Signup and view all the answers

Apoptosis is a pathological process only

False (B) Signup and view all the answers

Which of the following histological features is characteristic of apoptosis?

Cell shrinkage with dense cytoplasm and chromatin condensation (A) Signup and view all the answers

Flashcards

Biochemical alterations

The immediate and initial change seen in a cell undergoing injury.

Progression of cell injury

The sequence of changes observed in damaged cells, moving from invisible to visually apparent.

Acute cell swelling

An early sign of cell damage where cells swell due to water overload. This is reversible if the cause is addressed.