Tissues

1
Tissues

• Chapter 4

2
Tissues

• groups of cells with common role
• 4 basic types
• Epithelial
• Connective
• Muscular
• Nervous

3
Epithelial Tissue

• Cells close together continuous sheets
• Cover surfaces line cavities- always a free
  surface Apical surface
• Basement membrane of connective tissue
• No blood vessels- avascular
• Have a nerve supply
• High capacity for cell division.

4
Categories- Table 4.1

• Simple epithelium
• 1 layer of cells
• Stratified Epithelium
• more than 1 layer of cells
• Cell Shapes
• squamous, cuboidal, columnar, transitional
  (change shape)

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Simple Epithelium

• Squamous single layer of 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

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Simple Squamous Epitheliumsingle layer of flat
cells
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Simple Squamous Epitheliumsingle layer of flat
cells
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Simple Squamous Epitheliumsingle layer of flat
cells
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Simple Cuboidal Epitheliumcube shaped cells,
rounded nuclei
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Simple Cuboidal Epitheliumcube shaped cells,
rounded nuclei
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Simple Columnar EpitheliumMay be ciliated or
non-ciliated
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Simple Columnar EpitheliumMay be ciliated or
non-ciliated
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Simple Columnar EpitheliumMay be ciliated or
non-ciliated
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Simple Columnar EpitheliumMay be ciliated or
non-ciliated
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Pseudostratified Columnar appears stratified
nuclei at various levels
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Pseudostratified Columnar appears stratified
nuclei at various levels
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Stratified Squamous Epithelium

• Apical layer cells are flat
• Deep layers vary from cuboidal to columnar
• Cells in the basal layer divide and move upward
  toward apical surface
• Found in areas of surface wear tear

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Table 4.1f figure 1
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Table 4.1f figure 2
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Stratified Cuboidal Epitheliumrare
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Stratified Cuboidal Epitheliumrare
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Stratified Columnar Epitheliumrare
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Stratified Columnar Epitheliumrare
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Transitional Epitheliumvariable in
appearancecells can stretch
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Transitional Epitheliumvariable in
appearancecells can stretch
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Glandular Epithelium-Endocrine
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Glandular Epithelium-Endocrine
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Glandular Epithelium-Endocrine
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Glandular Epithelium-Endocrine
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Connective Tissue

• Most abundant tissue type
• small cells far apart
• large amount of extracellular material (matrix)
• Often good blood supply
• Found between other tissues
• Classified using matrix characteristics

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Connective Tissue Cellsvary with tissue type

• Fibroblasts- present in several tissues
• secrete fibers ground substance
• Macrophages- from monocytes
• Engulf bacteria cell debris by phagocytosis
• Plasma cells- develop from B lymphocytes
• Make antibodies

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Connective Tissue Cells

• Mast cells- near blood cells
• part of reaction to injury- histamine
• Adipocytes fat cells or adipose cells
• Store triglycerides (fat)

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Extracellular Matrix

• Fluid, gel or solid plus protein fibers
• Ground substance-between cells and fibers
• Fibers- 3 types
• Collagen fibers very strong flexible
• Elastic fibers smaller stretch and return to
  original length
• Reticular fibers provide support strength
• found in basement membranes organ support

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Figure 4.2
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Loose Connective Tissue

• Areolar
• Adipose
• Reticular

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Table 4.2a figure 1
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Table 4.2a figure 2
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Table 4.2b figure 1
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Table 4.2b figure 2
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Table 4.2c figure 1
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Table 4.2c figure 2
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Classification

• Dense Connective tissue
• Dense regular
• Dense irregular
• Elastic

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Table 4.2d figure 1
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Table 4.2d figure 2
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Table 4.2e figure 1
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Table 4.2e figure 2
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Table 4.2f figure 1
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Table 4.2f figure 2
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Cartilage

• Dense network of collagen elastic fibers
  embedded in chondroitin sulfate
• stronger than dense fibrous
• Cells chondrocytes
• Occur singly or in groups
• Found in spaces called lacunae
• Surrounded by perichondrium
• No blood vessels or nerves

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Classification - Cartilage

• 3 types
• Hyaline- fibers not easily visible
• Fibrocartilage- fibers visible
• Strongest type. E.g. in vertebral discs
• Elastic- chondrocytes in threadlike network e.g.
  ear cartilage

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Table 4.2g figure 1
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Table 4.2g figure 2
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Table 4.2h figure 1
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Table 4.2h figure 2
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Table 4.2i figure 1
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Table 4.2i figure 2
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Bone Osseous Tissue

• More dense matrix includes Calcium phosphorus
  salts
• Details in Chapter 6

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Liquid Connective Tissue

• Blood- matrix plasma
• More in chapter 14
• Lymph- matrix like blood but with less protein
• More in chapter 17

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Muscular Tissue

• large, elongated cells
• contractile cells
• Skeletal muscle tissue -named for location
• Cardiac muscle tissue- forms wall of heart
• Smooth muscle tissue found in walls of hollow
  organs

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Neural Tissue

• Nerve cells neuroglia
• Neurons- convert stimuli into nerve impulses and
  conduct them
• Neuroglia do not generate nerve impulses.
• Serve supportive functions

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Body Membranes

• 4 types of body (not cell) membranes
• Mucous Membranes line body cavities opening to
  exterior
• Secrete mucus
• Serous Membranes- surround moving organs
• Secrete serous fluid
• Synovial Membranes- line cavities of some joints.
• Secrete synovial fluid

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Tissue Repair

• New cells from stroma or parenchyma
• 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 from stroma gt scar tissue
  functional loss.