Functions:ProtectionSecretionAbsorptionTransportExcretionOthers: Sensation,
Protection Secretion Absorption Transport Excretion Others: Sensation, . Functions:
2.What are the characteristics ofepithelialtissue?
2.What are the characteristics of epithelial tissue?
Characteristics1.Epithelium covers free surfaces of the body(internalandexternal),forms glands,andtheductsfromglandsororgans.2.Most epithelia havea basement membranewhich attaches the epithelial cells to underlyingtissue.3.Epitheliumis mostly cellswithlittle extracellularmaterial.4.Epithelium is avascular (no blood vessels).Allexchangebetweenepitheliaand bloodtakesplacebydiffusionacrossthebasement membrane.5.Innervation
1. Epithelium covers free surfaces of the body (internal and external), forms glands, and the ducts from glands or organs. 2. Most epithelia have a basement membrane which attaches the epithelial cells to underlying tissue. 3. Epithelium is mostly cells with little extracellular material. 4. Epithelium is avascular (no blood vessels). All exchange between epithelia and blood takes place bydiffusion across the basement membrane. 5.Innervation Characteristics
(1+2)Polarisaton:---free surface: face air or other things;---basal surface: face underlying CT, havebasementmembrane.freesurface一Basementmembrane
(1+2) Polarisaton: -free surface: face air or other things; -basal surface: face underlying CT, have basement membrane. basal surface free surface
(3)Containmorecellsandverysmallamounts of extracellular matrix;福福
(3) Contain more cells and very small amounts of extracellular matrix;