CHAPTER 3 Tissues Four Major Families of Tissues body cavities lines ducts Epithelial tissue covers body surfaces lines organs lines Connective tissue protects supports body organs binds organs together site of storage energy provides immunity Muscular tissue provides physical force generates body heat during movement Nervous tissue controls body activities dictates what the response will be to that stimuli Tissues Group of cells with similar functions Pathologist exams tissues to see if anything is going on makes a diagnosis Histologist study tissues Cell Junctions There are five major types of cell junctions 1 Tight junctions water tight Plasma membranes are made out of proteins They stop anything from getting past the plasma membrane Found in stomach intestines urinary bladder Alludes access from from cell to another 2 Adherens junctions plaque bearing junctions Fastens cells together as well to help resist separation Stratified squamas 3 Desmosomes keratin similar to adhearing junctions except they have intermedicare filaments attachted to them Found where tissue is under great stress cardiac 4 Hemidesmosomes half a desmosome connect epithelial tissue and connective tissue 5 Gap junctions connexons fluid filled bridges help things get from one cell to another get electrical signals through from one cell to another Found in heart GI tract Comparison Between Epithelial and Connective Tissue Epithelial tightly packed Connective large amount of blood vessels Epithelial Tissue or Epithelium General features tightly packed Epithelium arranged in continuous sheets single or multiple layers good nerve supply avascular Cells are arranged in continuous sheets Cells have lateral surfaces apical free surface and basal surface attached to basement membrane Surfaces of Epithelial Cells Basement Membrane Basement membrane is made up of Basal lamina Reticular lamina secreted by connective tissue Copyright 2012 John Wiley Sons Inc Numerous cell junctions that securely attach neighboring Epithelium cells Avascular High capacity for cell division Numerous functions Covering and Lining Epithelium Arrangement of cells into layers reflects its location and function Simple unilaminar epithelium Pseudostratified epithelium Stratified multilaminar epithelium Covering and Lining Epithelium Cells may be categorized by cell shape Squamous flat Cuboidal cubed Columnar Transitional Types of Epithelial Tissues Simple epithelium Simple squamous Simple cuboidal Simple columnar Nonciliated Ciliated Pseudostratified columnar Nuclei in cells close together one layer thick simple squamos flat nuclei are simply located found in areas with very little wear and tear lungs or where you might need filtration kidneys on test actual histology picture One layer of cells that are cubed shaped secretion absorption lines tubles of kidneys also some ducts of a lot of our glands Column shaped cells one layer non ciliated found in small intestines have micro vili used to help increases efficiency of absorption One layer column shaped DO contain cilia found in urine tube upper respiratory system there to move something One layer scattered nuclei out of trachea know where nuclei are movement of material using ciliary action contains cilia MOST of upper resp system all psuedostratified are columnar Stratified Epithelial Tissues Stratified squamous Stratified cuboidal Stratified columnar Transitional Unlike simple epithelium cause it has more than one layer keratin surface cells that are dead they are filled with keratin found in lining of mouth and vagina Pap smear ratio of keratin and non keratinized cells most living cells often missed Offers protection lines ducts of sweat glands rare Rare protection secretion is its functions lines large ducts of some adult glands From urinary bladder has disk shaped but when extended stretched it changes shape transitional Glandular Epithelium Specialized epithelial cells organized to form glands that secrete substances into ducts onto a surface or into the blood Endocrine glands ductless secretes hormones ex thyroid pituitary Exocrine glands have ducts secretes saliva sweat pic know that this is an endocrine gland pic know that this is an exocrine gland Connective tissue is one of the most abundant and widely Connective Tissue distributed tissues in the body does not occur on a free surface binds things together supports other tissues protects other organs main source of immunity highly innovative has good nerve blood supply EXCEPT in tendons cartilage Fibroblasts make site cells retain capacity for cell division Macrophages develop from monosites engulf bacteria Plasma cells develop from V lymphosites produce debris antibodies Mast cells produce histomines Adipocytes fat cells White blood cells lucosites Connective Tissue Extracellular Matrix Glycosaminoglycans GAGs from carbs that are essential for life Hyaluronic acid found in joints helps lubricate joints Cells and Fibers in Connective Tissue Collagen provide strength flexibility to most of our Fibers Embedded in Extracellular Matrix tissue most abundant protein we have in our body tough resistant but pliable you can form it formed from protein collagen Elastic provides strength elasticity found in lungs can stretch up to 50 of original length then can go back Reticular spleen lymphnodes framework for organs Connective Tissue Embryonic connective tissue Mature Loose Dense Cartilage Bone Liquid Found almost exclusively in the embryo give rise to all other connective tissue AKA Wharton s jelly comes from umbilical cord found primary there DON T confuse with Mesenchyme cord blood transplants Has most stuff in it has all three of the fibers in it collagen reticular elastic highly vascularized good blood supply found in blood vessels skin be able to identify which is which by picture or she could draw arrows say what is that so know parts Adipose fill with fat two types white storing energy protects organs brown generates heat found in newborn you may see a newborn go under a heat lamp if they re small Has reticular fibers they form the framework stroma of organs binds things like muscle tissue together Nice parallel rows of collagen fibers imbedded in them is fibroblasts which make site cells forms tendons most ligaments less vascularized than loose connective tissue found in parts of body like knees shoulders elbows Some fibroblasts but collagen fibers are irregular located in dermis periostium bones heart valves Elastic provides