Study GuideAnatomy and Physiology–Tissues1.Epithelial TissueWhat is Epithelial Tissue?Epithelial tissue (epithelium)is a type of tissue made ofclosely packed cells. It forms thecoverings and liningsof many parts of the body.These cells are usually arranged like a “sheet,” and they protect body surfaces and control whatpasses in and out.1.1Main Characteristics of EpitheliumEpithelial tissue has some special features:1. Cells are tightly packedThe cells are close together withvery little spacebetween them.This means there isvery little intercellular material.2. Epithelium has no blood vessels (Avascular)Epithelium isavascular, which means itdoes not contain blood vessels.So how does it get nutrients and remove wastes?Bydiffusionfrom nearbyconnective tissue.3. It has two surfacesEpithelium has:•afree (apical) surface→ faces outside the body or inside a body cavity•abasal surface→ rests on connective tissueBetween the epithelium and connective tissue, there is a thin supportive layer called thebasementmembrane.Preview Mode
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