Page 15 - Headlines Histology2024_Neat

CYTOPLASMIC INCLUSIONS

• They are temporary lifeless accumulation of metabolites or cell products,
such as stored food, pigments and crystals.

Stored food

Glycogen
• The glycogen is stored chiefly in hepatocytes and in muscle cells.
• In H&E sections, glycogen is seen as clear rough-edged spaces.
• In EM, it can appear in two forms; ?-particles that are found in

chondrocytes and hepatocytes as rosettes of moderately electron-dense
particles.
• ?-particles, which are found in muscle cells as single particles that are little
larger than ribosomes.
Lipids
• The fat cells of adipose tissues and the fat storing cells of the liver store the
lipids.
• Routine processing generally extracts lipids from tissue and therefore, in
H&E sections, lipid droplets within cells appear as unstained vacuoles.
• Lipids are best demonstrated in frozen sections stained by specific lipid
methods such as osmium or sudan III with which lipids are stained black
and orange respectively.

Pigments

• They are substances that have their own color in their nature state.
Exogenous pigments
• The exogenous pigments are those that have been produced outside the

body. They include carotenes, dusts, minerals and tattoo marks.

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