Tissue Level of Organization Chapter 4 Lecture Notes

1
Tissue Level of OrganizationChapter 4 Lecture
Notes

• to accompany
• Anatomy and Physiology From Science to Life
• textbook by
• Gail Jenkins, Christopher Kemnitz, Gerard Tortora

2
Chapter Overview

• 4.1 Human Tissue Classifications
• 4.2 Epithelial Tissue
• 4.3 Connective Tissue
• 4.4 Membranes
• 4.5 Muscular Tissue
• 4.6 Nervous Tissue
• 4.7 Tissue Repair

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Essential Terms

• tissue
• group of similar cells that function together to
  carry out specialized activities and usually have
  a common embryonic origin
• histology
• science that deals with the study of tissues
• pathologist
• physician who specializes in laboratory studies
  of cells and tissues for changes that might
  indicate disease

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Introduction

• While cells are basic functional and structural
  unit of life, they function in groups as tissues
  to carry out specialized activities
• Properties of tissues are influenced by factors
  such as extracellular material and connections
  between cells
• Tissues may be hard, semisolid, or liquid
• Vary with kind of cells present, cellular
  arrangement, and types of fibers present

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Concept 4.1Human Tissue Classifications
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Human Body Tissues

• Classified into four groups according to
• function
• structure
• Groups
• epithelial
• connective
• muscle
• nervous

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Body Tissues Classification

• Epithelial Tissue
• covers body surfaces, lines hollow organs,
  cavities, and ducts, and forms glands
• Connective Tissue
• protects and supports body and organs
• binds organs together
• stores energy reserves as fat
• helps provide immunity

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Body Tissues Classification

• Muscular Tissue
• generates physical force
• Nervous Tissue
• monitors and responds to changes in a variety of
  conditions inside and outside the body
• helps maintain homeostasis

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Concept 4.2 Epithelial Tissues
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General Features

• Epithelium (singular) or epithelia (plural)
• lines body surfaces
• cells closely packed
• tightly held together with numerous junction
• cells arranged in sheets
• single layers simple
• multiple layers stratified
• surfaces
• apical free surface or superficial layer
• basal attached to basement membrane or deepest
  layer

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Figure 4.1
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Epithelial Tissue

• basement membrane
• thin extracellular layer made up of
• basal lamina
• closest to epithelial cells
• secreted by epithelial cells
• components
• collagen, laminin, and glycoproteins
• reticular lamina
• deep to basal lamina
• part of connective tissue layer
• produced by fibroblasts

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Epithelial Tissue

• Basement membrane functions
• attach and support epithelium
• migration surface for growth and repair
• filter large molecules and cells
• Epithelium characteristics
• avascular
• high rate of cell division
• because apical surface cells sloughed off, worn
  off, and damaged then replaced
• two types
• covering and lining
• glandular

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Figure 4.2
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Covering and Lining Epithelia

• Classified according to
• arrangement of cells in layers
• simple single
• stratified multiple
• pseudostratified single but appears multiple
• cell shapes
• squamous flat apical surface
• cuboidal shaped like cubes or hexagons
• columnar taller than wide, apical surface may
  have cilia or microvilli
• transitional change shape from cuboidal to flat
  and back allowing stretch and recoil

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Table 4.1 pt 1
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Table 4.1 pt 2
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Table 4.1 pt 3
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Table 4.1 pt 4
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Table 4.1 pt 5
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Table 4.1 pt 6
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Table 4.1 pt 7
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Glandular Epithelia

• Glandular cell function is secretion
• often lie in clusters deep to covering and lining
  epithelium
• consist of single or multiple cells
• Classification of glands
• exocrine
• into ducts
• onto a surface
• endocrine
• into the blood

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Table 4.1 pt 8
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Table 4.1 pt 9
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Concept 4.3 Connective Tissues
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Connective Tissue

• Most abundant tissue type
• Functions
• binds together, supports, strengthens other
  tissue types
• protects and insulates internal organs
• compartmentalizes structures
• major transport system
• major site of stored energy reserves
• main site of immune responses

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General Features

• Two basic elements
• cells
• extracellular matrix
• Characteristics
• do not occur on surfaces
• usually highly vascular
• exceptions include cartilage and tendons
• have nerve supply

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Types of Cells

• Major types of connective tissues have immature
  blast cells
• fibroblasts in loose and dense connective
• chondrobasts in cartilage
• osteoblasts in bone
• Blast cell characteristics
• mitotic
• secret matrix
• differentiate into -cyte cells

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Types of Cells

• fibroblasts
• macrophages
• mast cells
• adipocytes
• white blood cells (WBC)

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Figure 4.3
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Extracellular Matrix

• determines classification of connective tissues
• two components
• ground substance
• fibers

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Ground Substance

• between cells and fibers
• can be fluid, semifluid, or calcified
• functions
• supports cells
• binds cells together
• stores water
• provides medium for substance exchange
• active in tissue development, migration,
  proliferation, shape and metabolic functions

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Ground Substance

• contains large organic molecules
• complex combinations of polysaccharides and
  proteins
• glycosaminoglycans or GAGs
• trap water
• example hyaluronic acid

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Fibers

• Function to strengthen and support
• Three major types
• collagen
• elastic
• reticular

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Collagen Fibers

• very strong
• resist pulling forces
• not stiff
• often occur in parallel bundles
• most abundant protein in body 25 of total
  proteins
• found in most connective tissue types
• bone
• cartilage
• tendons
• ligaments

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Figure 4.3
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Elastic Fibers

• smaller in diameter than collagen
• branch and join together forming network
• protein named elastin
• can stretch up to 150 of relaxed length without
  breaking
• ability to return to original shape
• plentiful in
• skin
• blood vessel walls
• lung tissue

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Reticular Fibers

• collagen arranged in fine bundles
• coated with glycoprotein
• provide support in walls of blood vessels
• help form the basement membrane
• form network around cells of some tissues
• areolar
• adipose
• smooth muscle
• plentiful in reticular connective tissue

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Connective Tissue Types

• Two basic groups
• embryonic connective tissue
• mature connective tissue
• loose
• dense
• cartilage
• bone
• liquid

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Mature Connective Tissue

• loose
• areolar connective tissue
• adipose tissue
• reticular connective tissue
• dense
• dense regular
• dense irregular
• elastic connective
• cartilage
• hyaline
• fibrocartilage
• elastic cartilage
• bone
• liquid
• blood

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Figure 4.4
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Table 4.2a
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Table 4.2b
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Table 4.2c
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Table 4.2d
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Table 4.2e
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Table 4.2f
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Table 4.2g
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Table 4.2h
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Table 4.2i
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Table 4.2j
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Table 4.2k
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Concept 4.4 Membranes
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Membranes

• flat sheets of pliable tissue
• cover or line a part of the body
• epithelial membrane
• combination of epithelium and underlying
  connective tissue layer
• principle membrane types
• mucus membranes
• serous membranes
• cutaneous membrane
• synovial membrane

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Figure 4.5a
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Figure 4.5b
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Figure 4.5c
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Figure 4.5d
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Mucus Membrane

• also known as mucosa
• epithelial membrane
• epithelium and underlying connective tissue
• lines a body cavity that opens directly to
  exterior
• line entire
• digestive, respiratory, and reproductive tracts
• line most of
• urinary tract
• barrier to microbes and other pathogens
• mucus prevents drying out
• connective tissue layer is areolar
• lamina propria

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Figure 4.5a
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Figure 4.5b
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Figure 4.5c
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Figure 4.5d
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Serous Membrane

• also known as serosa
• epithelial membrane
• lines a cavity that does NOT open directly to
  surface
• covers organs within cavity
• connective tissue layer is areolar
• epithelium is simple squamous
• two layers
• parietal layer attaches to wall
• visceral attaches to organ

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Serous Membranes

• secretes serous fluid to lubricate membranes and
  allow layers to glide over one another
• pleura
• lungs and thoracic cavity
• pericardium
• heart and heart cavity
• peritoneum
• abdominal organs and cavity

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Cutaneous Membranes

• skin
• epithelial membrane
• covers surface of body
• superficial portion epidermis
• deeper portion dermis
• see Chapter 5

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Synovial Membranes

• lack epithelium
• not epithelial membranes
• line cavities of freely moveable joints
• composed of
• areolar connective tissue
• variable amounts of adipocytes, elastic fibers,
  and collagen fibers
• secret synovial fluid into joint cavity
• lubricates and nourishes cartilage covering bones
• line bursae (cushioning sacs) and tendon sheaths
• easing movement of muscle tendons

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Concept 4.5 Muscular Tissues
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Muscular Tissue

• generates physical force needed to make body
  structures move
• produces movement
• maintains posture
• generates heat
• three types
• skeletal
• cardiac
• smooth

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Skeletal Muscle

• striated
• long cells (up to 30-40cm)
• cylindrical in shape
• many nuclei at periphery of cell
• fibers are parallel
• voluntary

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Cardiac Muscle

• striated
• branched
• single nucleus at center of cell
• sometimes two nuclei
• intercalated discs
• cell junctions
• strengthen tissue and hold cells together
• provide route for quick conduction of impulses
• involuntary

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Smooth Muscle

• nonstriated
• unbranched
• small
• spindle shaped (thick middle, tapered ends)
• single nucleus at center of cell
• intercalated discs
• cell junctions
• strengthen tissue and hold cells together
• provide route for quick conduction of impulses
• involuntary

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Table 4.3 pt 1
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Table 4.3 pt 2
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Table 4.3 pt 3
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Concept 4.6 Nervous Tissues
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Nervous Tissue

• two principal types of cells
• neurons
• sensitive to various stimuli
• convert stimuli into impulses
• conduct impulses to
• other neurons
• muscular tissue
• glands
• parts of a cell
• cell body
• dendrites
• axon
• neuroglia
• smaller than neurons
• support, nourish, protect neurons

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Table 4.4
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Concept 4.7 Tissue Repair
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Tissue Repair

• ability to repair depends on
• extent of damage
• tissue type
• epithelium
• continuous capacity for renewal
• connective
• some have continuous capacity for renewal
• others replenish less readily because of smaller
  blood supply
• muscle
• relatively poor capacity for renewal
• nervous
• poorest capacity for renewal

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Tissue Repair

• New cells originate by cell division from
• parenchyma (functioning part of tissue)
• repair will be near-perfect reconstruction
• stroma (supporting connective tissue)
• repair will include new connective tissue and
  scar formation will occur
• original function of tissue or organ is impaired
• tissue repair affected by
• nutrition
• blood circulation

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End Chapter 4