Tissues

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Tissues
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Definitions

• Tissues are groups of cells that have the same
  structure and functions.
• The study of tissues is called HISTOLOGY
• Histos tissue ology field of study

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Classification of tissues

• Epithelial
• Simple (one layer)
• Squamous
• Cuboidal
• Cilindrical
• With microvilli or brush border.
• Cilia
• Pseudostratified
• Stratified (several layers)
• Squamous
• Cuboidal
• Cilindrical
• Transition

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Classification of Tissues

• Connective
• Proper
• Mesenchyme
• Loose connective
• Areolar
• Reticular
• Adipose
• Dense connective tissue
• Dense regular
• Dense irregular
• Cartilage
• Hyaline
• Elastic
• Fibrocartilage
• Oseous
• Blood

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Classification of Tissues

• Muscular
• Skeletal muscle
• Cardiac muscle
• Smooth muscle
• Nervous tissue

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Epithelial tissue

• Characteristics
• Polarity posses apical surface and basal
  surface.
• Cellularity and special contacts (tight
  junctions).
• Supported by connective tissue through basement
  membrane (basal lamina reticular lamina).
• Avascular no blood vessels.
• Regenerative cells regenerate.
• Function lining of surfaces (interior or
  exterior to the body)

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Figure 3.5
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Simple Epithelium

• Simple Squamous epithelium
• Description scale like flat cells.
• Function Allows passage of substances through
  filtration and diffusion.
• Located in endothelium (lining of blood vessels),
  kidney glomeruli, air sacs in the lung (alveoli).

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Simple squamous
Figure 4.1
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Figure 4.2
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Simple Epithelium

• Simple cuboidal epithelium
• Description cells are of cubic form.
• Function secretion and absortion.
• Located in kidney tubules, ovary surface

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Figure 4.3
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Simple Epithelium

• Simple Columnar (cilindrical) epithelium
• Description tall cells with round or oval
  nucleus.
• Function Absorption that can be increase by
  cytoplasmatic projections of microvilli,
  secretion of mucus. If ciliated, it propels mucus
  by ciliary action.
• Located in digestive track, small intestine,
  uterus, lower respiratory system (bronchioles).

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Figure 4.4
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Figure 4.5
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Simple Epithelium

• Pseudostratified columnar
• Description single layer of cells, with apparent
  different heghts due to the position of the
  nucleus.
• Function secretion and propulsion of mucus.
• Located in the trachea.

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Figure 4.6
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Simple Epithelium

• Pseudostratified columnar
• Description appears to be stratified squamous
  and cylindrical.
• Function allows stretching and containing urine
  (avoiding leakage into adjacent tissues).
• Found in the bladder.

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Stratified Epithelium

• Stratified Squamous epithelium
• Description multilayer squamous cells.
• Function protection of underlying tissues.
• Location Non keratinized (thin skin) are found
  in the esphagous, mouth,vagina. Keratinized
  (thick skin) palm and feet.

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Figure 4.7
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Stratified Epithelium

• Stratified Cuboidal epithelium
• Descriptionbilayer of cuboidal cells.
• Function secretion.
• Found in the ducts of glands such as mammary,
  sweat and salivary.

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Figure 4.8
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Stratified Epithelium

• Stratified Columnar epithelium
• Description Several layers of cylindrical cells.
  
• Function secretion.
• Found in the male urethra.

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Figure 4.9
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Stratified Epithelium

• Transitional epithelium
• Description Resembles both stratified sqamous
  and stratified cuboidal epithelium basal scells
  are cuboidal or cylindrical surface cells are
  domed or squamous.
• Function Allows distension and stretching.
• Found in the lining of the urethers, bladder and
  par of the urethra.

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Figure 4.10
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Connective Tissue Proper

• Areolar loose connective tissue
• Description loose collagen reticular and elastic
  fibers, prescence of fibroblasts, macrophages,
  mast cells.
• Function wraps provide nutrients and cushions
  organs.
• Found under epithelia, surrounds capillaries and
  packages organs, .

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Connective Tissue

• Function Support/connect tissues.
• Description
• Cells
• Fibroblast most common.
• Chondrocytes, ostoecytes secrete respective
  extracellular matrix.
• Myofibroblasts
• Adipocytes
• Fibres
• Collagen
• Estastin
• Reticulin
• Ground substance amorphous transparent material.
• Glucosaminoclycans (GAGs) Hyaluronic acid
• Glycoproteins fribrillin, fibronectin, integrin.

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Figure 4.11
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Connective Tissue Proper

• Reticular loose connective tissue
• Description predominant reticular fibers in a
  network.
• Function Provides structure to lymph organs.
• Located Found in lymph organs (thymus, lymph
  nodes).

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Figure 4.13
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Connective Tissue Proper

• Regular Dense connective tissue
• Parallel arranged collagen fibers with
  fibroblasts.
• Function Attaches muscles to bones or bones to
  bones. Posses great tensile strength in one
  direction.
• Forms tendons, ligaments, aponeurosis.

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Figure 4.15
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Connective Tissue Proper

• Irregular Dense connective tissue
• Description Irregular arranged fibers with
  fibroblasts. Forms the articulation capsules of
  organs and joints.
• Function Posses great tensile strength in
  several directions.
• Location reticular layer of the dermis, fibrous
  capsues of organs and joints.

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Figure 4.14
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Connective Tissue Proper

• Elastic Connective tissue
• Description Irregular arranged elastic fibers
  with fibroblasts. Makes the tunica media in blood
  vessels.
• Function Provides elasticity to the blood
  vessels.
• Location Tunica media of arteries and veins.

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Figure 4.16
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Connective Tissue Proper

• Adipose loose connective tissue
• Description adipocytes embeded in scarce areolar
  tissue.
• Function Energetic reserve, cushioning, thermal
  insulation.
• Location Hypodermis, kidneys, abdomen, breasts.

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Figure 4.12
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Cartilage

• Hyaline Cartilage
• Description firm amorphous matrix synthesized by
  chondroblasts. Mature matrix holds chondrocytes
  in lacunae.
• Function Allows resilience, flexibility and
  compressibility to forces.
• Located embryonic skeleton, joints, nose,
  trachea, ribs.

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Figure 4.17
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Cartilage

• Elastic cartilage
• Description similar to hyaline, but a grater
  ratio of elastic fibers.
• Function maintain structure while possesing
  great flexibility.
• Location outer ear, epiglotis.

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Figure 4.18
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Cartilage

• Fibrocartilage
• Descriptionsimilar to hyaline but a greater
  ratio of collagen fibers.
• Function posses high tensile strength but
  maintaining compressibility.
• Located intervertebral discs, knee joint, pubic
  symphisis.

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Figure 4.19
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Bone

• Compact bone
• Description Hard, calcified matrix.
  Impereameable. Vascularized. Osteocytes in
  lacunae.
• Function hematopoiesis (reb blood cell
  formation), storage of calcium and minerals.
  Composes the skeleton.
• Location bones

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Figure 4.20
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Figure 4.21
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Blood

• Description red, white cells and fibrous
  proteins (firbinogen) in a fluid matrix (plasma)
• Function transport of nutrients, wates, gases
  throughout the body.
• Located within blood vessels.

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Figure 4.22
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Muscle

• Skeletal muscle
• Description long, cylindrical, multinucleated,
  and striated.
• Function Voluntary movement locomotion.
• Located skeleton

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Figure 4.28
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Figure 4.30
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Muscle

• Cardiac Muscle
• Description branched, striated, uninucleated
  cells, connected by cell juntions (intercalated
  discs)
• Function propulsion of blood from the heart.
• Location heart.

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Figure 4.31
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Muscle

• Smooth muscle
• Description spindle shaped, uninucleated, no
  striations.
• Function creates peristaltic movement in
  digestive system and involuntary contraction of
  arrestor pili.
• Lacted hollow organs, dermis

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Figure 4.32
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Nervous tissue

• Description Composed mainly by neurons and
  support cells (glial cells).
• Function transmit electrochemical signals to
  sense and control the body.
• Location. Brain, spinal cord, nerves.

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Figure 4.33
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Figure 4.35
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Figure 4.37
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Figure 4.38
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• Note to extra practice, you find an atlas in the
  lab book as well as a tutorial in the PhysioEx CD.