Page 16 - Headlines Histology2024_Neat

Carotenes

• Carotenes are a family of fat-soluble compound found in vegetable such as
carrots, tomatoes and vegetable juice. When animals fed on carotene-
containing vegetables, it colors its body fat yellow. Carotenes are
provitamens and may be converted into vitamin A.

• Ingestion of large amount of carotenes cause the skin of the body to appear
yellow or even reddish color due to its great contents of carotenes. This
condition is called carotenemia (increase carotene level in the blood). It
might be confused with the more serious pathological condition called
jaundice (caused by increase bilirubin level in the blood).

Dusts

• The lungs of heavy smokers usually blackened due to accumulation of
carbon particles in the alveolar macrophages located in the wall of the lung
alveoli.

Minerals

• Silver causes a gray pigmentation of the body. Lead can impart a blue line
to the gum.

Tattoo marks

• They are inorganic pigments inserted deeply into the skin with needles.
• The pigments are ingested by the subcutaneous macrophages and remain

permanently within their cytoplasm.

Endogenous pigments

• They include hemoglobin, hemosiderin, bilirubin, melanin and lipofuscin.
Hemoglobin

• The hemoglobin is an iron-containing pigment of erythrocytes has the
function of oxygen transport throughout the body.

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