Histology Exam 2 PDF

LO1: List the four major tissue types. Tissue - a group or mass of similar cells working together to perform common functions. https://www.rxlist.com/histology/definition.htm  Epithelium = epithelial tissue LO2: Discuss general char...

LO1: List the four major tissue types. Tissue - a group or mass of similar cells working together to perform common functions. https://www.rxlist.com/histology/definition.htm  Epithelium = epithelial tissue LO2: Discuss general characteristics of epithelial tissue 2 Main types: Most epithelial cells are separated from the 1. Glandular epithelium- make up glands connective tissue by a sheet of extracellular material Cells are specialized to secrete substances called the BASEMENT MEMBRANE 2. Covering & Lining epithelium- Covers all apical surface body surfaces both inside and out. can be lined with Cells tightly microvilli or cilia packed together basal surface Usually has no vascular tissue (avascular) - no blood supply Innervated (supplied with nerves) Epithelial cells exhibit polarity (opposite sides Cells reproduce rapidly, results in rapid healing exhibit different features & functions) (and scarring)  LO3: Classify the different types of epithelial tissues based on distinguishing structural characteristics. Categorized based on : FIRST WORD SECOND WORD (1) Number of layers in the tissue: (2) Specific shape of each cell: Simple- single layer of cells Stratified- several layers of cells (square) (rectangle) One type of tissue can be arranged in different forms, each form has a different function. LO4: Describe the locations and functions of each type of epithelial tissue in the human body. Correlate function with structure for each tissue type. Endothelium (lining blood vessels) Lining of Air sacs in lungs kidney tubules round to oval nuclei *May contain mucus-secreting unicellular glands Disc-shaped (goblet cells) central nuclei digestive tract *Can have microvilli to increase surface area diffusion and filtration Named based on the shape of the cells in the (rare, in some glands) (rare) uppermost layer, even though the deeper layers might have different cell shapes. It can be further classified as: a modified stratified squamous epithelium (a) keratinized The surface cells are dead and packed with keratin protein (b) Nonkeratinized type line mouth, esophagus Ureters Bladder Cells are alive and lack keratin Urethra It lines hollow urinary system organs.  Pseudostratified Columnar Epithelium It is a simple columnar epithelium that appears stratified. -just a single layer of cells of differing heights, some not reaching the free surface, nuclei at different levels Can have cilia (hair-like projections) & mucus-secreting cells It lines most of the upper respiratory passages. Function: Mucus Secretion & propulsion of mucus by ciliary action  LO5: Describe the structure of the basement membrane Thin, acellular structure, specialized part of the extracellular matrix (ECM) Located between any form of epithelium and its underlying connective tissue Epithelium 2 layers: Lamina lucida BASAL LAMINA Lamina densa RETICULAR LAMINA lamina reticularis Connective tissue  Connective tissue LO6: Describe the structural elements of the connective tissue EXTRACELLULAR MATRIX (ECM) Limited # 3 Types of Fibers: Long & thin, form networks Strongest fibers matrix-secreting cell (-blast) Elastic (Elastin) fibers Collagen fibers Fills the space b/w cells & fibers Mature cell (-cyte) Gel-like, amorphous material 10% Large organic molecules + 90% Water (Interstitial fluid) Glycosaminoglycans (GAGs): unbranched polysaccharides. Examples include hyaluronic acid, chondroitin sulfate, and heparin sulfate. Proteoglycans: formed by GAGs linked to a core protein. Reticular fibers Glycoproteins Similar to collagen Also contains other molecules like adhesion proteins fibers but form (fibronectin) that help connect cells and other ECM components. networks for support "Connective tissue" is a term used to describe various body tissues that connect, support, and bind other tissues together. https://biologydictionary.net/connective-tissue/ https://courses.lumenlearning.com/  Connective tissue Proper Specialized loose dense bone blood cartilage consists of blood cells in a fluid areolar adipose reticular matrix (plasma) regular irregular elastic