CBIO 2200 Edition Lecture 6 Outline of Last LectureI. Processes of membrane transportII. Vesicular TransportIII. The Cell InteriorChapter 5 - HistologyIV. Introduction to Ch. 5 Outline of Current Lecture I. Classes of Epithelium and Cell ShapeII. Simple EpitheliaIII. Stratified EpitheliaIV. Connective Tissue FunctionsV. Adipose TissueVI. CartilageCurrent LectureI. Classes of Epithelium and Cell Shapea. Simple epithelium: one layer of cellsb. Stratified epithelium: contains more than one layer; above the first layer, cells do not touch basement membranec. Shapes:i. Squamous – can be simple or stratifiedii. Columnar – simple or stratifiediii. Cuboidal – simple or pseudo-stratifiedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.d. Pseudo-stratified epithelium: looks stratified but it’s now; all of the cells touch the basement membranee. Stratified columnar is very rareII. Simple Epitheliaa. Four typesi. Simple squamous – single row of thin cellsii. Simple cuboidal – typically around ductsiii. Simple columnar – single row of tall and narrow cellsiv. Pseudo-stratified columnar – ciliated cells; tend to be found in respiratorytract; looks multilayered, nuclei at several layers1. Often associated with goblet cells – produce mucous for lubrication and getting rid of things; in respiratory tract to remove dust particles 2. Goblet cells are also associated with simple columnarIII. Stratified Epitheliaa. Some cells resting directly on othersb. Three stratified epithelia are names for their shapes of their surface cellsi. Stratified squamous – our skin1. Deepest layers undergo mitosis (divide)a. Exfoliation od desquamation – shedding off of cellsb. Die when they reach their surface because blood vessels don’t reach from basement membrane top layer; shed tope layer cells constantly2. Two kinds of stratified squamous epitheliaa. Keratinized – Keratin is a protein; in skin, has a very dark pink color to it because keratin is stained; usually where skin is dry (palms of hands, soles of feet)b. Non-keratinized stratified squamous epithelium – no dark stain because there is no keratin; most regions of epithelium (mouth, vagina)ii. Stratified cuboidal1. More than one layer of cuboidal cells2. Found in glands (sweat, hormones, sperm)iii. Stratified columnar (rare)c. Fourth type – transitional epithelium i. Associated with urinary system: in bladder, kidney, ureters, urethra, umbilical chordii. Stratified columnar – can tell by ballooning of cells on top, allow cell to transition/expand; ballooned cells flatten out and bladder can expandIV. Connective Tissue Functionsa. Main functionsi. Binding organs togetherii. Supportiii. Physical protectioniv. Immune protectionv. Movementvi. Storage (fat/adipose cells)vii. Heat production: for infants, because they are born with brown fat which produces heatviii. Transport – blood vessels in connective tissueb. Four broad categoriesi. Fibrous connective tissue: cells, fibers, ground substances1. Fibersa. Collagenous fibers – collagen b. Reticular fibers – collagen coated with glycoproteinc. Elastic fibers – made of elastin, provide flexibility2. Ground substance (the filler or matrix)a. Glycosaminoglycans (GAG) – composed of unusual disaccharides called amino sugars and have uronic acid attached to themi. Chondroitin sulfateii. Hyaluronic acidiii. Hepariniv. The above three play a part in joint’s healthb. Proteoglycanc. Adhesive glycoproteinsd. Play structural part in keeping tissues togetherii. Adipose tissueiii. Supportive connective tissue (bone and cartilage)iv. Fluid connective tissue (blood)c. Cellsi. Fibroblasts – produce fibersii. Macrophages – destroy foreign matteriii. Leukocytes – other white blood cells iv. Plasma cells – B-lymphocytes that produce antibodiesv. Mast cells – secrete heparin and histamine (causes swelling in nasal cavities)vi. Adipocytes – fat cells, main cell type in adipose tissuesd. Fibrous connective tissuei. Types:1. Loose connective tissue – has a lot of cells but a lot of matric/ground substance between cellsa. Areolar – stained pinki. Found in skin, blood vessels, etc.b. Reticular – must stain them with silveri. Find it in stroma which provides framework for organs2. Dense connective tissue – fibers with very little space between thema. Regular – tend to be a very regular patter to it; sometimes wavy, sometimes notb. Irregular – doesn’t look like any other cell; no patternV. Adipose Tissuea. We just see outline of fat cells/cell membranes (just looks like white space)b. Round shapec. Adipose tissue is mainly composed of adipocytes VI. Cartilagea. Supportive connective tissue with flexible, rubbery matrixb. Chondroblasts: produce cartilage, immature cellsi. Get trapped in cavities called lacunae and then become chondrocytesc. Chondrocytes: mature cartilage cellsd. Perichondrium: connective tissue that covers it, not all cartilage has thise. Types of cartilage vary with fiber typesi. Hyaline1. Glassy appearance 2. Contain lacunae 3. Covered with perichondrium4. Can be considered articular cartilage (elbow, knee, places where bones rub against each other)a. Keeps friction down between bonesb. Padding between bonesii. Fibrocartilage1. You can see bundles of collagen2. Does not have perichondrium3. Absorbs a lot of shock4. In vertebral column between disksiii. Elastic1. Contains elastic fibers2. Covered with perichondrium 3. In ear, places with flexible cartilagef. Does not have blood vessels associated with it, so it is difficult to healg. Nature of collagen fibers determine the type of