Cellular Injury II - Wasit University Module

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Questions and Answers

What is coal worker's pneumoconiosis commonly known as?

Asbestosis

Silicosis

Berylliosis

Anthracosis (correct)

What is the primary characteristic of lipofuscin?

It appears bright red on H&E stains.

It is a harmful pigment to cells.

It is a sign of aging and free radical injury. (correct)

It is found only in the skin.

What results in dystrophic calcification?

Abnormal local deposition in dying tissues (correct)

Hypercalcemia due to metabolic disturbances

Increased calcium metabolism

Normal serum calcium levels

In which condition is metastatic calcification most likely to occur?

Hypercalcemia due to metabolic disorders Signup and view all the answers

Which of the following statements about exogenous pigments is true?

They can be phagocytosed by macrophages in the skin. Signup and view all the answers

What is a characteristic appearance of fat necrosis under microscopy?

Shadowy outlines of necrotic cells Signup and view all the answers

Which condition is associated with traumatic fat necrosis?

Breast trauma Signup and view all the answers

What is a feature of a white infarct?

Typically results from occlusion of an end artery Signup and view all the answers

What primarily mediates fat necrosis?

Lipases Signup and view all the answers

What does apoptotic cell death involve?

Enzyme activation called caspases Signup and view all the answers

What is a characteristic feature of coagulative necrosis?

Fine structural details are lost. Signup and view all the answers

Which of the following describes the cytoplasm of fat necrosis?

Granular pink appearance Signup and view all the answers

In coagulative necrosis, what occurs to the nuclei of affected cells?

Nuclei are lost. Signup and view all the answers

What is an outcome of saponification in fat necrosis?

Calcium soaps deposit in tissues Signup and view all the answers

What is the most common manifestation of necrosis in tissues?

Coagulative necrosis. Signup and view all the answers

Which pattern of necrosis is characterized by ischaemic conditions?

Infarction (ischaemic necrosis) Signup and view all the answers

Which condition leads to protein denaturation and subsequent coagulative necrosis?

Prolonged ischemia. Signup and view all the answers

What is the staining characteristic of the cytoplasm in coagulative necrosis?

Deeply eosinophilic. Signup and view all the answers

What type of tissue architecture is commonly maintained in coagulative necrosis?

Basic shape and architecture. Signup and view all the answers

What occurs during enzymatic digestion in the context of necrosis?

Necrotic debris is cleared away. Signup and view all the answers

What is indicated by the presence of a hemorrhagic zone in kidneys affected by coagulative necrosis?

Dying or not fully dead cells. Signup and view all the answers

What primarily characterizes cytoplasmic changes in necrosis?

Loss of glycogen particles and vacuolation Signup and view all the answers

Which term describes the fragmentation of a nucleus in necrosis?

Karyorrhexis Signup and view all the answers

What is a characteristic finding in necrotic cells when observed under electron microscopy?

Dilation of mitochondria with amorphous densities Signup and view all the answers

Which type of necrosis is characterized by the presence of caseating granulomas?

Caseation necrosis Signup and view all the answers

Which of the following describes pyknosis?

Nuclear shrinking and increased basophilia Signup and view all the answers

What leads to the more homogeneous appearance of the cytoplasm during necrosis?

Increased binding of eosin to denatured proteins Signup and view all the answers

What process characterizes karyolysis?

Basophilia fading in the chromatin Signup and view all the answers

What morphological change is indicative of cytoplasmic necrosis?

Cytoplasmic vacuolation Signup and view all the answers

What type of cell death is characterized by shrinkage and fragmentation?

Apoptosis Signup and view all the answers

Which of the following is a trigger for intrinsic apoptosis?

Withdrawal of growth factors Signup and view all the answers

What is typically observed in necrosis compared to apoptosis?

Cell swelling and disorganization Signup and view all the answers

What is a characteristic feature of apoptotic nuclei?

Pyknosis and karyorrhexis Signup and view all the answers

Which of the following conditions typically leads to apoptotic cell death?

Viral hepatitis Signup and view all the answers

What role do cytotoxic T cells play in apoptosis?

Inducing extrinsic apoptosis Signup and view all the answers

Which of the following best describes the cell degradation process in apoptosis?

Phagocytosis without inflammation Signup and view all the answers

In terms of histological features, which statement is true for apoptosis?

Chromatin is condensed and clumped Signup and view all the answers

Study Notes

Cell Necrosis

Defined as the death of contiguous cell groups in tissues or organs, characterized by enzyme degradation of irreversibly damaged cells.

Morphological Changes

Cytoplasmic Changes: Increased eosinophilia, loss of cytoplasmic RNA, homogeneous appearance, loss of glycogen, and vacuolation from organelle digestion.
Nuclear Changes: Includes chromatin clumping and three patterns:
- Karyolysis: Fading basophilia of chromatin.
- Pyknosis: Nuclear shrinkage with increased basophilia, condensing into a solid mass.
- Karyorrhexis: Fragmentation of the nucleus.

Electron Microscopy Findings

Necrotic cells show plasma membrane discontinuities, dilated mitochondria with amorphous densities, myelin figures, osmiophilic debris, and aggregates of denatured protein.

Types of Necrosis

Coagulative necrosis
Liquefactive necrosis
Fat necrosis
Caseation (caseous) necrosis
Gangrenous necrosis

Dynamics of Necrosis

Necrosis is a dynamic process influenced by:
- Degree of enzyme release from dying cells or infiltrating inflammatory cells.
- Degree of protein denaturation which determines coagulative vs liquefactive necrosis.
- Clearance of necrotic debris through autolysis, heterolysis, fragmentation, and phagocytosis.

Coagulative Necrosis

Features preserved cellular outlines but with loss of nuclei and fine structural details. Common in ischemic injury, characterized by a solid tissue mass.

Fat Necrosis

Associated with adipose tissue, often seen in acute pancreatitis and breast trauma. Exhibits grossly chalky white appearance and microscopically shows necrotic cell outlines and calcium soap deposits.

Infarction (Ischemic Necrosis)

Classified as either coagulative or liquefactive necrosis depending on the tissue involved. Infarcts can be:
- White: Due to end artery occlusion.
- Red/Hemorrhagic: From venous occlusion, dual blood supply, or previously congested tissues.

Apoptosis

A regulated cell death involving activation of caspases that degrade nuclear and cytoplasmic proteins. Cells may appear eosinophilic with distinct size and shape.

Physiological and Pathological Apoptosis

Physiologically occurs for removing host cells post-function, e.g., neutrophils.
Pathological triggers include radiation, toxic drugs, viral infections, and duct obstruction-related atrophy.

Apoptosis vs. Necrosis

Apoptosis: single cell death, shrinkage, membrane integrity preserved, and no inflammation.
Necrosis: group cell death, swelling, disrupted membranes, and associated inflammation.

Triggers and Mechanisms of Apoptosis

Triggered intrinsically by growth factor withdrawal or DNA damage, extrinsically by death signals like TRAIL and Fas ligand.

Pathologic Calcification

Abnormal deposition of calcium salts:
- Dystrophic Calcification: Local deposition in dying tissues without hypercalcemia.
- Metastatic Calcification: Deposition in normal tissues due to hypercalcemia from metabolic disturbances.

Pigmentation

Exogenous Pigments: E.g., tattoo particles phagocytosed by macrophages.
Endogenous Pigments: Include hemosiderin, melanin, and lipofuscin, notable indicators of aging and cellular injury, often appearing yellow-brown on H&E stains.

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Description

This quiz focuses on the mechanisms of disease as part of the Cellular Injury II module from Wasit University's College of Medicine. Designed for medical students, it covers essential concepts related to cellular injury and its implications in various diseases. Test your knowledge and understanding in this critical area of study.