Gastric caner

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MORPHOLOGY OF FUNGI
(a) General. Fungi vary widely in size and shape, from unicellular, microscopic
organisms to multicellular forms easily seen with the naked eye. Individual
cells range from 1 µ to 30 µ. Microscopic fungi exist as either molds or
yeasts or both. Internally, fungal cells are fairly typical eucaryotic cells.

CLASSIFICATION OF FUNGI
Fungi are usually classified according to biological taxonomy based upon the type of hypha, spore, and reproduction. There are four classes of fungi, whose characteristics are shown in Table 51.1 and figure 51.2.
(a) Class Phycomycetes. The algal fungi: bread molds and leaf molds. The only known mycosis (fungal disease) caused by fungi of this class ismucormycosis, a very rare fungal growth of the upper respiratory tract,
bronchial mucosa, and lungs. It occurs largely as a complication of a
chronic, debilitating disease.

Class Ascomycetes. The sac fungi: yeasts, mildews, and cheese molds.
Fungi of this class are implicated in only three fungus diseases, all of which
are rare.
(c) Class Basidiomycetes. Mushrooms, toadstools, rusts, and smuts. The only
pathogens in this class are the mushrooms of the genus Amanita, which
cause severe systemic poisoning (sometimes death) when eaten.
(d) Class Deuteromyceters. Fungi imperfecti: a heterogeneous collection of
fungi without sexual reproduction. Most of the pathogens encountered in
medical mycology belong to this class.

1.CONIDIUM

2.ASPERGILLUS
Aspergillus was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Micheli was reminded of the shape of an aspergillum (holy water sprinkler), from Latin spargere (to sprinkle), and named the genus accordingly

Detection of fungi
Fungal testing typically includes a microscopic examination of the sample on a slide, sometimes using a preparation or stain to aid in detection of fungal elements. This may be sufficient to determine that the infection is due to a fungus and, with superficial infections, no further testing may be required