Nasopharyngeal carcinoma virus

#The virus associated with nasopharyngeal carcinoma is:
a) Epstein Barr
b) Cytomegalo virus
c) Hepatitis
d) Herpes virus

The correct answer is A. Epstein Barr.

Nasopharyngeal carcinoma affects younger age group and half of the patients will present with secondaries in neck.

Epstein-Barr virus is also implicated as an etiological factor for Burkitts Lymphoma and infectious mononucleosis.

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Punched out edge of ulcer

# Punched out edge is characteristic of which type of ulcer?
a) Tuberculosis
b) Rodent
c) Syphilitic
d) Non specific

The correct answer is C. Syphilitic.

•  Non-specific ulcer = Shelving edge
• Tuberculous ulcer = Undermined edge
• Rodent ulcer = Raised, pearly white and beaded 
• Squamous cell carcinoma = Rolled out, everted 
• Syphilitic = Punched out edge; Base covered with wash leather slough

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Cellular response to Stress and Noxious Stimuli

Cellular responses to stress and noxious stimuli:
Normal cells handle normal physiologic demands, maintaining a steady state called homeostasis.

More severe physiologic stresses and some pathologic stimuli may bring about a number of physiologic and
morphologic cellular adaptations, during which new but altered steady states are achieved, preserving the viability of the cell.

The adaptive response may consist of an increase in the number of cells, called hyperplasia, increase in the
sizes of individual cells, called hypertrophy.

Conversely, Atrophy is an adaptive response in which there is a decrease in the size and function of cells.

Nature of the stimulus and Cell response/adaptation towards it
- Increased demand = Hyperplasia and hypertrophy
- Decreased nutrients and stimuli = Atrophy
- Chronic irritation = Metaplasia
- Reduced oxygen supply, chemical and microbial injury = Acute reversible injury
- Progressive damage including the DNA = Necrosis and Apoptosis
- Metabolic alterations = Intercellular accumulations and calcification

Mechanism of plasma membrane damage in ischemia

# The major mechanism of damage to plasma membrane in ischemia is:
A. Reduced intracellular pH
B. Increased intracellular accumulation of sodium
C. Increased Ca++ ions in the cytosol
D. Reduced aerobic respiration

The correct answer is C. Increased Ca++ ions in the cytosol.

The ion calcium is critical for cell damage. Influx of calcium acts as second messenger and activates wide spectrum of enzymes that destroy cellular organelles.

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