Copyright 2010, John Wiley & Sons, Inc. Chapter 4 Tissues.
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Transcript of Copyright 2010, John Wiley & Sons, Inc. Chapter 4 Tissues.
Copyright 2010, John Wiley & Sons, Inc.
Chapter 4Tissues
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 Cuboidal Epithelium• 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 Columnar Epithelium 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.
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.
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 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 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.
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.
Glandular Epitheliumcells that are specialized to produce and secrete substancesEndocrine glands are ductlessExocrine 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.
Structural Types of Exocrine Glands
5-9
Copyright 2010, John Wiley & Sons, Inc.
Types of Glandular SecretionsMerocrine glands
• fluid product - exocytosis• salivary glands• pancreas•sweat glands
Apocrine glands • cellular product• portions of cells• mammary glands• ceruminous glands
Holocrine glands• secretory products• whole cells• sebaceous glands
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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:
Secrete fibers Macrophages:
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.
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.
Adipose Tissue• cushions• insulates• store fats• beneath skin• behind eyes• around kidneys and heart
Copyright 2010, John Wiley & Sons, Inc.
Reticular Connective Tissue composed of reticular fibers supports walls of liver, spleen, lymphatic organs
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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.
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.
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:
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Hyaline Cartilageappears clear because fibers are not easily visible
• most abundant• ends of bones• nose, respiratory passages• embryonic skeleton
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Fibrocartilage fibers visible
Strongest typeshock absorber
• intervertebral discs• pads of knee and pelvic girdle
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Elastic Cartilage chondrocytes in threadlike elastic network
• flexible• external ear, larynx
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.
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 Types1. Mucous membranes: line body cavities
and passageways open to the exterior Secrete mucus
2. Serous membranes: line closed cavities and surrounds organs located there
Serous fluid reduces friction Parietal and visceral layers Pleura, pericardium, peritoneum
Copyright 2010, John Wiley & Sons, Inc.
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)
Body Membranes: Four Types
Copyright 2010, John Wiley & Sons, Inc.
Muscular Tissue Functions
Produce movements, release heat Cells
Elongated, contractile (called muscle fibers) ThreeTypes
Skeletal muscle: Cardiac muscle: Smooth muscle:
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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
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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, but serve supportive functions
• found in brain, spinal cord, and peripheral nerves
• sensory reception
Copyright 2010, John Wiley & Sons, Inc.
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)
1. Autograft (Autologous) – Auto = self• Use your own tissue• No rejection
2. Isograft (Isologous) – Iso = equal• Use tissue from an identical twin• First Kidney Transplant – Dec 23, 1954
Copyright 2010, John Wiley & Sons, Inc.
3. Allograft (Allogenic) – Allo = Different Use tissue from a different person Rejection – may need immunosuppression
4. Xenograft (Xenologous) – Xeno = Foreign
• Use tissue from a different species
5. Biocompatible/Biodegradable material – inert = not rejected (no immune response)
• 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 ApplicationCollagen Disorders
Chondrodysplasia• collagen chains too wide• stunted growth• deformed joints
Dystrophic epidermolysis bullosa• breakdown of collagen that attaches skin layers• stretchy skin• lax joints
Hereditary osteoarthritis• change in amino acid in collagen• painful joints
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