Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 4 Tissues Copyright 2010, John Wiley & Sons, Inc. Tissues 4 basic types: Epithelial Connective Muscular Nervous Copyright 2010, John Wiley & Sons, Inc. Epithelial Tissue Cells lie close together in continuous sheets with little extracellular material Cover surfaces and line cavities; always a free (apical) surface Forms glands Basement membrane of connective tissue Has no blood vessels (avascular) Has a nerve supply Has a high capacity for cell division Copyright 2010, John Wiley & Sons, Inc. Categories- Table 4.1 Arrangement of cells in layers Simple: 1 layer of cells Stratified: more than 1 layer of cells Cell Shapes Squamous - flat Cuboidal - squares Columnar - rectangle Transitional - change shape Copyright 2010, John Wiley & Sons, Inc. Simple Squamous Epithelium Single layer flat cells Important for filtration (kidneys) or diffusion (lungs, capillaries) Called endothelium when lining heart, blood and lymphatic vessels Called mesothelium when in serous membranes Copyright 2010, John Wiley & Sons, Inc. Simple Squamous Epithelium Copyright 2010, John Wiley & Sons, Inc. Simple Squamous Epithelium Copyright 2010, John Wiley & Sons, Inc. Simple Squamous Epithelium Copyright 2010, John Wiley & Sons, Inc. Simple Cuboidal Epithelium • • • • • Single layer - Cube shaped cells Rounded nuclei function in secretion & absorption in kidneys cover ovaries function in secretion in glands Copyright 2010, John Wiley & Sons, Inc. Simple Cuboidal Epithelium Copyright 2010, John Wiley & Sons, Inc. Simple Columnar Epithelium Single layer rectangle shaped cells cilated or noncilated • all nuclei near basement membrane • intestine - microvilli • increases surface area for absorption • often have goblet cells – secrete mucus • line uterus, stomach, etc. – protects underlying tissues, secretes digestive fluids, & absorbs nutrients Copyright 2010, John Wiley & Sons, Inc. Simple Columnar Epithelium Copyright 2010, John Wiley & Sons, Inc. Pseudostratified Columnar Appears stratified; nuclei at various levels • often have cilia & goblet cells – line & sweep debris from respiratory tubes • female reproductive tract cilia aid in moving eggs Copyright 2010, John Wiley & Sons, Inc. Pseudostratified Columnar Copyright 2010, John Wiley & Sons, Inc. Stratified Squamous Epithelium Apical layer cells are flat Deep layers vary from cuboidal to columnar Cells in basal layer divide and move upward toward apical surface Found in areas of surface wear and tear Copyright 2010, John Wiley & Sons, Inc. Stratified Squamous Epithelium • protect underlying layers • can accumulate keratin in outer layer • outer layer of skin • line oral cavity (mouth), throat, vagina, and anal canal Copyright 2010, John Wiley & Sons, Inc. Stratified Squamous Epithelium Copyright 2010, John Wiley & Sons, Inc. Stratified Cuboidal Epithelium Rare 2-3 layers of cube-shaped cells line ducts of mammary glands, sweat glands, salivary glands, and the pancreas Several layers provide greater protection Copyright 2010, John Wiley & Sons, Inc. Stratified Cuboidal Epithelium Copyright 2010, John Wiley & Sons, Inc. Stratified Columnar Epithelium Rare top layer elongated cells cube-shaped cells in deeper layers line vas deferens, male urethra, and part of pharynx Copyright 2010, John Wiley & Sons, Inc. Stratified Columnar Epithelium Copyright 2010, John Wiley & Sons, Inc. Transitional Epithelium cells can stretch cube-shaped and elongated cells Designed to distend & return to normal size line urinary bladder, ureters, and part of urethra Copyright 2010, John Wiley & Sons, Inc. Transitional Epithelium Copyright 2010, John Wiley & Sons, Inc. Glandular Epithelium cells that are specialized to produce and secrete substances Endocrine glands are ductless Exocrine glands have ducts Unicellular • composed of one cell (goblet cell) Multicellular • composed of many cells • sweat glands, salivary glands, etc. Copyright 2010, John Wiley & Sons, Inc. Glandular Epithelium-Endocrine Copyright 2010, John Wiley & Sons, Inc. Structural Types of Exocrine Glands Copyright 2010, John Wiley & Sons, Inc. 5-9 Types of Glandular Secretions Merocrine glands Apocrine glands • fluid product exocytosis • salivary glands • pancreas •sweat glands • cellular product • portions of cells • mammary glands • ceruminous glands Copyright 2010, John Wiley & Sons, Inc. Holocrine glands • secretory products • whole cells • sebaceous glands 5-10 Glandular Epithelium-Exocrine Copyright 2010, John Wiley & Sons, Inc. Glandular Epithelium-Exocrine Copyright 2010, John Wiley & Sons, Inc. Connective Tissue Most abundant tissue type typically found between other tissues Small cells far apart with large amount of extracellular material (matrix) Has good blood supply exception: cartilage - avascular Copyright 2010, John Wiley & Sons, Inc. Connective Tissue Cells Fibroblasts: Macrophages: Secrete fibers Engulf bacteria and cell debris - phagocytosis Plasma cells: Make antibodies Copyright 2010, John Wiley & Sons, Inc. Connective Tissue Cells Mast cells: Part of an inflammatory reaction: produce histamine - dilates blood vessels Adipocytes: fat cells energy provide protection Copyright 2010, John Wiley & Sons, Inc. Extracellular Matrix Fluid, gel or solid + protein fibers found between cells and fibers Fibers: 3 types Collagen fibers: very strong and flexible Elastic fibers: smaller stretch and return to original length Reticular fibers: provide support and strength Found in basement membranes Copyright 2010, John Wiley & Sons, Inc. Connective Tissue Copyright 2010, John Wiley & Sons, Inc. Loose Areolar Connective Tissue • mainly fibroblasts • fluid to gel-like matrix • collagenous fibers • elastic fibers • bind skin to structures • beneath most epithelia • between muscles Copyright 2010, John Wiley & Sons, Inc. Areola Connective Tissue Copyright 2010, John Wiley & Sons, Inc. Adipose Tissue • cushions • insulates • store fats • beneath skin • behind eyes • around kidneys and heart Copyright 2010, John Wiley & Sons, Inc. Adipose Tissue Copyright 2010, John Wiley & Sons, Inc. Reticular Connective Tissue composed of reticular fibers supports walls of liver, spleen, lymphatic organs Copyright 2010, John Wiley & Sons, Inc. Reticular Connective Tissue Copyright 2010, John Wiley & Sons, Inc. Dense Regular Connective Tissue • packed collagenous fibers • elastic fibers • few fibroblasts • bind body parts together • tendons, ligaments, dermis • poor blood supply Copyright 2010, John Wiley & Sons, Inc. Dense Regular Connective Tissue Copyright 2010, John Wiley & Sons, Inc. Elastic Connective Tissue • abundant in elastic fibers • some collagenous fibers • fibroblasts • attachments between vertebrae • walls of large arteries, airways, heart Copyright 2010, John Wiley & Sons, Inc. Elastic Connective Tissue Copyright 2010, John Wiley & Sons, Inc. Cartilage Dense network of collagen and elastic fibers Stronger than dense fibrous connective tissue Cells: chondrocytes Very few; occur singularly or in groups Found in spaces called lacunae Has no blood vessels or nerves rigid matrix Copyright 2010, John Wiley & Sons, Inc. Classification: Cartilage Types Hyaline: Fibrocartilage: Elastic: Copyright 2010, John Wiley & Sons, Inc. Hyaline Cartilage appears clear because fibers are not easily visible • most abundant • ends of bones • nose, respiratory passages • embryonic skeleton Copyright 2010, John Wiley & Sons, Inc. Hyaline Cartilage Copyright 2010, John Wiley & Sons, Inc. Fibrocartilage fibers visible Strongest type shock absorber • intervertebral discs • pads of knee and pelvic girdle Copyright 2010, John Wiley & Sons, Inc. Fibrocartilage Copyright 2010, John Wiley & Sons, Inc. Elastic Cartilage chondrocytes in threadlike elastic network • flexible • external ear, larynx Copyright 2010, John Wiley & Sons, Inc. Elastic Cartilage Copyright 2010, John Wiley & Sons, Inc. Bone: Osseous Tissue Forms most of the skeleton Supports, protects, and allows movements site of blood formation and storage of minerals Solid matrix made rigid by calcium and phosphorus salts osteocytes (mature bone cell) in lacunae (hollow space) Copyright 2010, John Wiley & Sons, Inc. Copyright 2010, John Wiley & Sons, Inc. Liquid Connective Tissue Blood: found within blood vessels Matrix is plasma (fluid) Cells: red blood cells, white blood cells, platelets transports defends clotting Copyright 2010, John Wiley & Sons, Inc. Liquid Connective Tissue Lymph: found within lymph vessels Matrix is lymph: similar to plasma but with much less protein Some white blood cells Copyright 2010, John Wiley & Sons, Inc. Body Membranes: Four Types Mucous membranes: line body cavities and passageways open to the exterior 1. Secrete mucus Serous membranes: line closed cavities and surrounds organs located there 2. Serous fluid reduces friction Parietal and visceral layers Pleura, pericardium, peritoneum Copyright 2010, John Wiley & Sons, Inc. Body Membranes: Four Types 3. Synovial membranes: line cavities of most joints Made of connective tissues (no epithelium) Secrete synovial fluid that reduces friction and lubricates and nourishes cartilage 4. Cutaneous membranes: skin (chapter 5) Copyright 2010, John Wiley & Sons, Inc. Muscular Tissue Functions Cells Produce movements, release heat Elongated, contractile (muscle fibers) Three Types 1. 2. 3. Skeletal muscle: Cardiac muscle: Smooth muscle: Copyright 2010, John Wiley & Sons, Inc. Skeletal Muscle attached to bones striated voluntary Copyright 2010, John Wiley & Sons, Inc. Smooth Muscle walls of organs skin walls of blood vessels involuntary not striated Copyright 2010, John Wiley & Sons, Inc. Cardiac Muscle Intercalated disks Striated Not voluntary Copyright 2010, John Wiley & Sons, Inc. Nervous Tissue Functions: conduct nerve impulses Types of cells Neurons: convert stimuli into nerve impulses and conduct them Neuroglia: do not generate nerve impulses, serve supportive functions • found in brain, spinal cord, and peripheral nerves • sensory reception Copyright 2010, John Wiley & Sons, Inc. Nervous Tissues Copyright 2010, John Wiley & Sons, Inc. 5-23 Tissue Repair Epithelial cells originate from stem cells in defined areas of tissue layer Bone regenerates readily, cartilage poorly Muscular tissue can replace cells but slowly Nerve tissue is poorest at replacement although some stem cells seem to be available Replacement scar tissue with functional loss. Copyright 2010, John Wiley & Sons, Inc. Tissue and Organ Sourcing Histocompatability: ABO/Rh; HLA (Human Leukocyte Antigens) Autograft (Autologous) – Auto = self 1. • • Use your own tissue No rejection Isograft (Isologous) – Iso = equal 2. • • Use tissue from an identical twin First Kidney Transplant – Dec 23, 1954 Copyright 2010, John Wiley & Sons, Inc. Allograft (Allogenic) – Allo = Different 3. Use tissue from a different person Rejection – may need immunosuppression Xenograft (Xenologous) – Xeno = Foreign 4. • Use tissue from a different species Biocompatible/Biodegradable material – inert = not rejected (no immune response) 5. • • • Plastic, titanium, aluminum, gortex Used as scaffold in tissue engineering 1938 – Growing organs in laboratory Copyright 2010, John Wiley & Sons, Inc. What causes rejection? Immune Response: Host v. Graft – most rejections Host rejects the transplanted tissue Graft v. Host – some rejections Transplanted tissue rejects the host GVHD (Graft Versus Host Disease) Bone marrow transplants/Face transplants Copyright 2010, John Wiley & Sons, Inc. Donor Cell or Tissue Sources: Donation Stem Cells – Embryonic Stems/Adult Stems iPS (induced Pluripotent Stem – made from skin) Copyright 2010, John Wiley & Sons, Inc. Clinical Application Collagen Disorders Chondrodysplasia Dystrophic epidermolysis bullosa • collagen chains too wide • stunted growth • deformed joints • breakdown of collagen that attaches skin layers • stretchy skin • lax joints Hereditary osteoarthritis • change in amino acid in collagen • painful joints Copyright 2010, John Wiley & Sons, Inc. 5-25