EPITHELIUM CONNECTIVE TISSUE SKIN
EPITHELIA GLANDS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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that it contains many blood vessels.
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that it does not contain any blood vessels.
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that it is made of many layers.
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that it secretes mucous.
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Detailed explanation-1: -Epithelial tissues do not contain blood vessels and as such are avascular. Connective tissues are usually highly vascular and so the nearby connective tissue provides essential nutrients (from the blood) to the epithelial tissue.
Detailed explanation-2: -Epithelial layers contain no blood vessels (avascular), so they must receive nourishment via diffusion of substances from the underlying connective tissue, through the basement membrane. Cell junctions are especially abundant in epithelial tissues.
Detailed explanation-3: -Epithelial tissue does not contain blood vessels to prevent bleeding because this tissue is constantly exposed to mechanical and chemical wear and tear. Although this tissue is avascular, it is well supplied with nutrients through diffusion mechanism.
Detailed explanation-4: -Epithelia do not have their own blood supply (avascular), they rely on diffusion for exchange of oxygen and metabolites. Epithelia contain specialised cell-cell junctions that bind adjacent cells to each other.