Histology Certification Pathological Changes 4

Question 1

Which pattern of apoptosis is characterized by caspase activation, DNA laddering, and phagocytosis without inflammation?

Accepted Answer

Both intrinsic and extrinsic pathways share these terminal features

Answer

Both the intrinsic and extrinsic apoptotic pathways converge on the same executioner caspases, producing DNA laddering and apoptotic bodies cleared by phagocytes without inflammation.

Question 2

In an H&E section, apoptotic cells appear as:

Accepted Answer

Small, intensely eosinophilic cells with condensed, fragmented nuclei

Answer

Apoptotic cells shrink, their cytoplasm becomes deeply eosinophilic, and the nucleus undergoes pyknosis and karyorrhexis (condensation and fragmentation).

Question 3

Which pro-apoptotic protein, when released from the mitochondrial intermembrane space, directly activates the caspase cascade?

Accepted Answer

Cytochrome c

Answer

Cytochrome c is released from mitochondria and binds Apaf-1 to form the apoptosome, which activates procaspase-9 and triggers the caspase cascade.

Question 4

The extrinsic apoptotic pathway is initiated by binding of which ligand to its death receptor?

Accepted Answer

FasL (CD95L) to Fas (CD95)

Answer

FasL binding to Fas recruits FADD and procaspase-8, forming the death-inducing signaling complex (DISC) to activate the extrinsic pathway.

Question 5

Calcification found within a previously necrotic focus, such as an old tuberculous granuloma, is classified as which type?

Accepted Answer

Dystrophic calcification

Answer

Dystrophic calcification occurs in dead or dying tissue despite normal serum calcium levels, as in old granulomas, atherosclerotic plaques, and necrotic tumors.

Histology Certification Practice Test

Histology Certification Practice Test

Histology Certification Pathological Changes 4