General Pathology Practice Questions

Q: What is the clinical evidence of dentinogenesis imperfecta?

Defective dentine and obliterated pulp chamber. **Explanation:** **Dentinogenesis Imperfecta (DI)** is an autosomal dominant disorder of dentin formation caused by mutations in the **DSPP gene** (Dentin Sialophosphoprotein). **Why Option B is Correct:** The hallmark of DI is the formation of abnormal, poorly mineralized dentin. Histologically and radiographically, this manifests as: 1. **Defective Dentin:** The dentin is softer and contains irregular, sparse tubules. 2. **Obliteration of Pulp Chambers:** Because the odontoblasts are functionally deranged, they produce dentin in an accelerated, disorganized manner, eventually filling and completely obliterating the pulp chambers and root canals. This is a classic radiographic sign. **Analysis of Incorrect Options:** * **Option A:** DI primarily affects dentin. While the enamel may flake off easily because the underlying dentino-enamel junction (DEJ) is smooth (lacking the normal scalloping), the **enamel itself is structurally normal**. * **Option C:** Interestingly, teeth with DI actually show a **decreased rate of caries**. This is attributed to the rapid attrition (wear) of the teeth and the absence of patent dentinal tubules, which prevents bacterial invasion. * **Option D:** **Oligodontia** (congenital absence of six or more teeth) is not a feature of DI. DI affects the structure of the teeth that are present, not their number. **High-Yield Clinical Pearls for NEET-PG:** * **Appearance:** Teeth often exhibit a characteristic **translucent, opalescent, or "amber"** color. * **Radiographic Sign:** "Bell-shaped" crowns with cervical constriction and thin, short roots. * **Association:** DI Type I is associated with **Osteogenesis Imperfecta** (look for "blue sclera" in the clinical vignette). DI Type II and III occur in isolation.

Q: Caspases are associated with which of the following?

Embryogenesis. **Explanation:** **Caspases** (Cysteine-aspartic proteases) are the executioner enzymes of **Apoptosis** (programmed cell death). Unlike necrosis, apoptosis is a highly regulated, energy-dependent process essential for normal development and homeostasis. **Why Embryogenesis is Correct:** During **embryogenesis**, apoptosis is vital for structural remodeling. Caspases facilitate the removal of redundant tissues, such as the disappearance of interdigital webbing (to form fingers and toes), the involution of the mullerian/wolffian ducts, and the pruning of excess neurons during neurodevelopment. Without caspase-mediated apoptosis, congenital anomalies like syndactyly (fused digits) would occur. **Why Other Options are Incorrect:** * **Hydropic degeneration:** This is a form of reversible cell injury characterized by cellular swelling due to ATP depletion and failure of Na+/K+ pumps. It is not a programmed process. * **Collagen hyalinisation:** This refers to a descriptive histological term where tissues appear glassy and pink (e.g., in old scars or vascular walls). It is a feature of chronic injury or aging, not caspase activity. * **Fatty degeneration (Steatosis):** This involves the abnormal accumulation of triglycerides within parenchymal cells (like the liver), usually due to toxins, protein malnutrition, or diabetes. **High-Yield Clinical Pearls for NEET-PG:** * **Initiator Caspases:** Caspase 8 and 9. * **Executioner Caspases:** Caspase 3, 6, and 7 (**Caspase 3** is the most common executioner). * **Marker of Apoptosis:** Annexin V (binds to phosphatidylserine) and DNA laddering on electrophoresis. * **Bcl-2:** An anti-apoptotic protein that inhibits the release of Cytochrome C; its overexpression is linked to Follicular Lymphoma [t(14;18)].

Q: Which of the following is NOT a morphological feature of apoptosis?

Inflammation. Apoptosis is a form of **programmed cell death** characterized by a controlled, energy-dependent process that eliminates unwanted cells without eliciting an inflammatory response. **1. Why Inflammation is the Correct Answer:** Unlike necrosis, apoptosis does not involve the release of intracellular contents into the surrounding tissue. The plasma membrane remains intact, and the resulting apoptotic bodies are rapidly phagocytosed by macrophages. Because there is no leakage of lysosomal enzymes or cellular debris, **inflammation is absent**. In contrast, necrosis is always associated with inflammation due to membrane rupture. **2. Analysis of Incorrect Options:** * **Cell Shrinkage (A):** This is a hallmark of apoptosis. The cell becomes smaller, the cytoplasm becomes dense, and organelles are more tightly packed. * **Chromatin Condensation (B):** This is the most characteristic feature of apoptosis. Chromatin aggregates peripherally under the nuclear membrane (pyknosis), followed by nuclear fragmentation (karyorrhexis). * **Apoptotic Bodies (D):** The cell breaks into membrane-bound fragments containing portions of cytoplasm and nucleus. These are "bite-sized" portions for phagocytes. **Clinical Pearls for NEET-PG:** * **Caspsases:** These are the executioner enzymes of apoptosis (Cysteine proteases). * **DNA Laddering:** On electrophoresis, apoptotic DNA shows a characteristic "step-ladder" pattern (fragments in multiples of 180-200 bp), whereas necrosis shows a "smear" pattern. * **Flippase/Annexin V:** In apoptosis, **Phosphatidylserine** flips from the inner to the outer leaflet of the plasma membrane, acting as an "eat-me" signal for macrophages. This can be detected clinically by Annexin V staining. *Note: Current available textbook excerpts did not meet relevance criteria for specific morphological descriptions of apoptosis.*

Question 1

Apoptosis does not occur by the normal caspase pathway in which of the following?

Accepted Answer

Neurons

Answer

Liver

Answer

Muscle

Answer

Skin

Question 2

What is the clinical evidence of dentinogenesis imperfecta?

Accepted Answer

Defective dentine and obliterated pulp chamber

Answer

Defective enamel and dentine

Answer

Increased rate of caries

Answer

Oligodontia

Question 3

Which of the following is an example of a direct acting toxin?

Accepted Answer

Mercuric chloride

Answer

Acetaminophen

Answer

Carbon tetrachloride

Answer

Bromobenzene

Question 4

Which type of gangrene is typically caused by known infectious agents?

Accepted Answer

Wet gangrene

Answer

Dry gangrene

Answer

Pyodermatous gangrene

Answer

Mourner's gangrene

Question 5

Caspases are associated with which of the following?

Accepted Answer

Embryogenesis

Answer

Hydropic degeneration

Answer

Collagen hyalinisation

Answer

Fatty degeneration

Question 6

Dissolution of nuclear chromatin and fading of chromatin is known as:

Accepted Answer

Karyolysis

Answer

Pyknosis

Answer

Karyorrhexis

Answer

Emiocytosis

Question 7

Which of the following is NOT a clinical feature of gangrene?

Accepted Answer

Gas produced by the organism in the kidney leading to foaming kidney

Answer

Foul smelling necrosis of the muscle bundle

Answer

Loss of contractility of the muscle

Answer

The skin becomes dull red, green, or black

Question 8

Which of the following is NOT true of dystrophic calcification?

Accepted Answer

Serum calcium levels are high

Answer

Occurs in damaged tissue

Answer

Tuberculous lesions

Answer

Atherosclerotic lesions

Question 9

Which of the following causes the maximum effect in myocardial reperfusion injury?

Accepted Answer

Free radicals

Answer

Neutrophil

Answer

Monocytes

Answer

Eosinophils

Question 10

Which of the following is NOT a morphological feature of apoptosis?

Accepted Answer

Inflammation

Answer

Cell shrinkage

Answer

Chromatin condensation

Answer

Apoptotic bodies

General Pathology — MCQs

General Pathology — MCQs

On this page

Practice by Chapter

Want unlimited practice?