KIN 2500 Tissues Supplemental Instruction Histology study of tissues Cytology study of cells Tissue a group of cells that usually have a common origin and function together to carry out specific activities Types of Tissues matching 1 Epithelial tissue b 2 Connective tissue d 3 Muscular tissue a 4 Nervous tissue c a Composed of cells specialized for contraction and generation of force b Covers body surfaces and lines hollow organs body cavities and ducts c Detects changes in a variety of conditions inside and outside the body and responds by generating electrical signals called nerve impulses that activate muscular contractions d Protects and supports the body and its organs Types of Cell Junctions fill in the blank 1 Gap Junctions membrane proteins called connexins form fluid filled tunnels called connexons plasma membranes are separated by a gap allow cells within a tissue to communicate with one another 2 Desmosomes contain plaque contain transmembrane glycoproteins that attach cells to one another the plaque attaches to intermediate filaments contribute to the stability of the cell 3 Tight Junctions consists of weblike strands of transmembrane proteins that fuse together the outer surfaces of two PMs inhibit passage of substances between the cells 4 Hemidesmosomes do not link adjacent cells the transmembrane glycoprotein integrin connect and anchor the cell to a basement membrane 5 Adherens Junctions contain plaque cells are joined together by transmembrane proteins called cadherins this junction resists separation of cells Epithelial vs Connective Tissues Epithelial Avascular Connective Vascular Numerous cells tightly put together On the surface of glands and body structures Widely scattered large amounts of extracellular material intertwined Under epithelial tissue almost everywhere in the body KIN 2500 Tissues Supplemental Instruction Vascular or avascular Vascular lots of blood flow Avascular not a lot of blood flow Number and spacing of cells Location in body Epithelial Tissue 1 Basement membrane b 2 Lateral surface e 3 Epithelial tissue a 4 Basal surface d 5 Apical free surface c a Forms the innermost and outermost surfaces of body structures and forms glands b Thin extracellular layer between epithelium and connective tissue c The surface that faces the body surface a body cavity the lumen of an internal organ or a tubular duct d The surface that is found opposite of the apical surface e The surface of an epithelial cell that faces an adjacent cell on either side Classification of Epithelial Tissues Arrangement of Cells in Layers Simple Epithelium Single layer of cells Filtration Diffusion osmosis secretion and absorption Pseudostratified Epithelium False Epithelium One layer looks like more than one Secretion of mucous Stratified Epithelium Multiple layers Protection Wear and tear KIN 2500 Tissues Supplemental Instruction Always touch the basal layer but not always the apical Cell Shapes Squamous Thin allow for the rapid passage of substances Cuboidal As tall as they are wide function in secretion and absorption Columnar Taller than wide protect underlying tissues secretion and absorption Transitional Change shape as organs expand and collapse Covering and Lining Epithelium 1 Simple squamous single layer of flat cells centrally located nucleus 2 Simple cuboidal single layer of cube shaped cells centrally located nucleus 3 Simple non ciliated columnar single layer of nonciliated column like cells nucleus near base of cell a Two types of cells i Goblet cells modified columnar epithelium cells that secrete mucous onto their apical surface projections are found on the apical surface ii Columnar epithelium with microvilli fingerlike cytoplasmic 4 Simple ciliated columnar single layer of ciliated column like cells nucleus near bottom of cell can contain goblet cells 5 Pseudostratified Columnar several layers of cells nuclei found at different levels all cells are attached to basement membrane but not all reach apical surface 6 Stratified squamous two or more layers of cells cells in superficial layers are squamous cells in deeper layers are cuboidal or columnar 7 Stratified cuboidal two or more layers of cells cells in apical layer are cube shaped rare type of epithelium 8 Stratified columnar basal layers consist of shortened and irregularly shaped cells column shaped cells found in apical layer rare 9 Transitional appearance is variable looks very similar to stratified cuboidal epithelium Glandular Epithelium Function secretion KIN 2500 Tissues Supplemental Instruction o Accomplished by glands that can consist of a single cell or a group of cells All glands in the body are classified as either endocrine or exocrine Endocrine make hormones and secrete them into interstitial fluid and diffuse into the bloodstream without flowing through ducts maintain homeostasis Exocrine secretory products are released into ducts that empty onto the covering and lining epithelium produce sweat oil earwax saliva etc Connective Tissue Functions o Supports and strengthens other body tissues o Protects internal organs o Compartmentalizes structures such as skeletal muscles o Serves as a transport system throughout the body blood o Stores energy adipose fat tissue o Immune responses Types of Connective Tissue Cells 1 Fibroblasts large flat cells with branching processes a Present in all general connective tissues very numerous b Migrate through the connective tissue secreting the fibers and certain components of the ground substance of the extracellular matrix 2 Macrophages have an irregular shape with short branching projections a Develop from monocytes can be fixed or wandering 3 Plasma cells small cells that develop from B lymphocytes a type of white blood cell a Secrete antibodies 4 Mast Cells found in large numbers along the blood vessels that supply connective tissue produce histamine a chemical that dilates small blood vessels as part of the inflammatory response 5 Adipose Cells also called fat cells a Store triglycerides b Found deep to the skin and around organs 6 White blood cells not found in large numbers in connective tissue but migrate from blood to connective tissue during certain conditions Embryonic Connective Tissue KIN 2500 Tissues Supplemental Instruction 1 Mesenchyme consists of irregularly shaped mesenchymal cells found in embryos forms all other types of connective tissue 2 Wharton s Jelly exclusively in the umbilical cord of the fetus Mature Connective Tissue LOOSE