(精选)【医学英文课件】 Histology – Epithelial Tissue教学课件.ppt

Histology – Epithelial Tissue Biology 2121 Introduction Histology There are (4) types of tissue: 1. Epithelial 2. Connective 3. Muscle 4. Nervous Similarities between tissue types: 1. All contain cells 2. Cells that make up tissues have similar functions Characteristics of Epithelial Tissue General Characteristics 1. Covers and lines organs/cavity walls 2. Forms boundaries Special Characteristics 1. As an interface tissue Protection, absorption, filtration, secretion and excretion 2. Exhibits polarity Apical (superior) and basal (inferior) surfaces 3. Avascular, but innervated 4. Supported by connective tissue Cells are attached to a ‘basement’ membrane 5. Ability to regenerate 6. “Cellular” Epithelial Structure Apical Basement Membrane Apical Basement Membrane The epithelial cells lie on the reticular lamina (collagen – CT) Reticular lamina is bound to another CT called areolar CT. Together this structure is called the basement membrane” Classification and Examples 1. Simple Epithelium Single layer All cells anchored to basement membrane 2. Simple Squamous Kidney – filtration 3. Simple Cuboidal Kidney tubules Filtration; secretion, absorption Simple Epithelia 4. Simple Columnar Tall, thin cells Absorptive cells (small intestine) Goblet Cells 5. Pseudostratified ‘Ciliated’ Columnar Epithelium “Pseudostratified” ? Trachea Goblet Cells and Mucus