The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane Basement membrane A darkly stained mat-like extracellular matrix (ecm) that separates cell layers, such as epithelium from endothelium or a layer of connective tissue. The ecm layer that supports an overlying epithelium or endothelium is called basal lamina. Basement membrane (bm) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. Bm, composed mainly of type IV collagen; glycoprotein laminin; and proteoglycan, provides barriers as well as channels between interacting cell layers. Thin Basement Membrane Nephropathy (TBMN), the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. The epithelium is classified according to the cells (squamous, cuboidal, columnar), the number of layers, and other unique characteristics either due to function (transitional epithelium allowing distention) or appearance (pseudostratified epithelium giving a false impression of multiple layers). The surface epithelium has multiple functions, which include protection, secretion Secretion Coagulation Studies, filtration, and sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology reception.
Last updated: Apr 18, 2023
A complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body:
These cells exhibit polarity:
The surface epithelium does not possess blood vessels; therefore, nutrients and oxygen are received from adjacent connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology.
Note that there are tissues that have both:
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