SIMPLE SQUAMOUS EPITHELIUM
The simple squamous epi variety of epithelium consists of a single layer of thin flat cells which are roughly polygonal in outline. The free surface of each flat cell faces a cavity or the lumen of a tubular structure, while the basal surface rests on a basement membrane, The cells have serrated or wavy margins and the adjacent cells fit closely together to form a continuous sheet. Each cell contains a flattened nucleus located in the center of the cell. Presence of the nucleus in the central region of the flat cell causes the plasma membranes above and below to bulge slightly.
On surface view the closely fitting polygonal cells appear like a mosaic. Sections made perpendicular to the epithelial sheet show that in profile (ie, in side view) the individual cells give fusiform (spindle-shaped) appearance because the central region of each cell is thicker (due to the presence of the nucleus), while peripherally the cytoplasm is very (having a thickness of 0.1um or less). thin Simple squamous epithelium is of common occurrence in the body. Chief examples of this type of epithelium are the eindothelium which covers the internal surface of heart, blood vessels and lymph vessels, and the mesothelium which lines the pericardial, pleural and peritoneal cavities. The type I alveolar cells, which line the major part of the lung alveoli, are also of simple squamous variety.
Squamous is a Latin term derived from squama which means scale of a tish. In anatomy the term squanious is used to denote a flat, plate-like structure.
Because of its thinness, the simple squamous epithelium allows rapid diffusion of gases, water, and water-soluble molecules. However, in many locations, the simple squamous epithelium is also engaged in active transport and vesicular transport.
FOUND IN:
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| Simple squamous epithelium |
On surface view the closely fitting polygonal cells appear like a mosaic. Sections made perpendicular to the epithelial sheet show that in profile (ie, in side view) the individual cells give fusiform (spindle-shaped) appearance because the central region of each cell is thicker (due to the presence of the nucleus), while peripherally the cytoplasm is very (having a thickness of 0.1um or less). thin Simple squamous epithelium is of common occurrence in the body. Chief examples of this type of epithelium are the eindothelium which covers the internal surface of heart, blood vessels and lymph vessels, and the mesothelium which lines the pericardial, pleural and peritoneal cavities. The type I alveolar cells, which line the major part of the lung alveoli, are also of simple squamous variety.
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| Simple squamous epithelium. |
Squamous is a Latin term derived from squama which means scale of a tish. In anatomy the term squanious is used to denote a flat, plate-like structure.
Because of its thinness, the simple squamous epithelium allows rapid diffusion of gases, water, and water-soluble molecules. However, in many locations, the simple squamous epithelium is also engaged in active transport and vesicular transport.
FOUND IN:
- Lining of blood vessels and heart
- Lining of alveoli of lungs
- Kidney parietial layer of bowman capsule
