Chapter 4Tissue:The Living Fabric

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Chapter 4-TissueThe Living Fabric
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HISTOLOGY-THE STUDY OF TISSUES

• MOST ORGANS CONTAIN ALL 4 TISSUE TYPES-BUT THEIR
  ARRANGEMENT DETERMINES THE STRUCTURE AND FUNCTION
  OF THE ORGAN.
• TISSUES-TYPES
• EPITHELIAL-COVERING
• CONNECTIVE-STRUCTURE
• MUSCLE-MOVEMENT
• NERVOUS-COMMUNICATION AND CONTROL

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EPITHELIAL TISSUE

• WHERE IT OCCURS IN THE BODY
• 1.COVERING AND LINING
• 2.GLANDULAR

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ROLE/FUNCTION

• 1.PROTECTION-DEFINES BOUNDARIES
• 2.ABSORPTION
• 3.FILTRATION
• 4.EXCRETION
• 5.SECRETION
• 6.SENSORY RECEPTION

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CHARACTERISTICS

• 1. CELLULARITY
• 2. SPECIALIZED CONTACT
• a.TIGHT JUNCTIONS
• b.DESMOSOMES
• 3. POLARITY
• a.APICALSURFACE
• -MICROVILLI/BRUSH BORDERS
• -CILIA
• b.BASAL SURFACE
• 4. BASEMENT MEMBRANE-THE SUPPORT AND BOUNDARY FOR
  EPITHELIAL LAYERS
• a.BASAL LAMINA-NON-CELLULAR GLYCOPROTEIN
  SELECTIVE FILTER AND SCAFFOLDING
• b.RETICULAR LAMINA-COLLAGEN PROTEIN FIBER
• 5 .INNERVATED BUT AVASCULAR
• 6 .REGENERATES

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CLASSIFICATION

• 1.LAYERS
• a.SIMPLE-SINGLE
• b.STRATIFIED-TWO OR MORE
• 2.SHAPES
• a.SQUAMOUS-FLAT,SCALE-LIKE-DISC SHAPED
  NUCLEUS
• b.CUBOIDAL-CUBED,W/ROUND NUCLEUS
• c.COLUMNAR-TALL,COLUMN SHAPE-NUCLEUS
  ELONGATED AND GENERALLY AT THE BASE OF THE
  CELL

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SIMPLE EPITHELIA

• 1.SIMPLE SQUAMOUS-FLATTENED LAYER,DISC SHAPED
  NUCLEUS,SPARSE CYTOPLASM
• FUNCTION-DIFFUSION AND FILTRATION OF
  MATERIALS. EG.LUNGS, KIDNEY GLOMERULI, HEART
  LINING, BLOOD AND LYMPHATIC VESSELS
  (ENDOTHELIUM), VENTRAL BODY CAVITY SEROSA
  (MESOTHELIUM)

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SIMPLE CUBOIDAL

• 2.SIMPLE CUBOIDAL-CUBE-LIKE CELLS W/DARK CIRCULAR
  NUCLEI FUNCTION-SECRETION/
• ABSORPTION. EG.KIDNEY TUBULES, SECRETORY PORTIONS
  OF SMALL GLANDS, OVARY SURFACE

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SIMPLE COLUMNAR

• 3.SIMPLE COLUMNAR-TALL CELLS, OVAL NULCEI AT
  BASE, OFTEN HAVE MICROVILLI, CILIA, OR MUCOUS
  SECRETING GLANDS CALLED GOBLET CELLS.
• -FUNCTION-ABSORPTION, SECRETION, MOVEMENT OF
  SUBSTANCES.EG. UTERINE TUBES, RESPIRATORY TRACT

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PSEUDOSTRATIFIED COLUMNAR

• 4.PSEUDOSTRATIFIED COLUMNAR-SINGLE LAYER OF TALL
  CELLS, BUT SOME DONT REACH THE APICAL SURFACE.
  NUCLEI ARE AT DIFFERENT LEVELS. SOME MAY HAVE
  CILIA OR GOBLET CELLS.
• FUNCTION-SECRETION AND THE MOVEMENT OF MOSTLY
  MUCOUS EG.DUCTS OF LARGE GLANDS, MALE URETHRA,
  TRACHEA AND RESPIRATORY TRACT.

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STRATIFIED EPITHELIA

• 1.STRATIFIED SQUAMOUS-THE UPPER LAYERS ARE
  SQUAMOUS, LOWER LAYERS USUALLY CUBOIDAL. (APICAL
  LAYER DETERMINES THE CLASSIFICATION) MITOSIS FROM
  BASAL CELLS- CONSTANT SINCE UPPER LAYERS ARE
  SLOUGHED.THICK AND DURABLE
• FUNCTION-PROTECTION-UPPER LAYERS, KERATINIZED
  (PROTECTIVE PROTEIN) LOWER LAYERS ARE
  NON-KERATINIZED. EG.SKIN AND BODY OPENINGS THAT
  ARE CONTINUOUS W/SKIN.

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STRATIFIED CUBOIDAL

• 2.STRATIFIED CUBOIDAL-RARE,FORM LARGE DUCTS OF
  SOME GLANDS
• -FUNCTION-PROTECTION EG.LARGEST SWEAT, MAMMARY
  AND SALIVARY GLANDS.

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Stratified Columnar

• 3.STRATIFIED CULUMNAR- RARE, BASAL CELLS ARE
  USUALLY CUBOIDAL.
• FUNCTION-PROTECTION, SECRETION EG.MALE URETHRA,
  LARGE DUCTS IN SOME GLANDS.

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TRANSITIONAL EPITHELIUM

• 4.TRANSITIONAL EPITHELIUM-BASAL CELLS ARE
  CUBOIDAL OR COLUMNAR. APICAL CELLS VARY
• -FUNCTION-STETCHING, PERMITS DISTENTION
  EG.URINARY BLADDER.

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GLANDULAR EPITHELIA

• A GLAND IS ONE OR MORE CELLS THAT MAKE AND
  SECRETE A SUBSTANCE.
• CLASSIFICATION BY DUCTS
• 1.ENDOCRINE-DUCTLESS-HORMONE PRODUCTION
• 2.EXOCRINE-DUCTS-MANY TYPES OF SECRETIONS
  EG.SWEAT, OIL, SALIVA, BILE, MUCOUS
• 3.UNICELLULAR-NO DUCTS, SECRETE DIRECTLY. EG.
  GOBLET CELLS-MUCOUS

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GLANDULAR EPITHELIA, CONTD

• 4.MULTICELLULAR-HAVE DUCTS AND SECRETORY UNITS
• SIMPLE AND COMPOUND GLANDS

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GLANDULAR EPITHELIA, CONTD

• SECRETORY UNITS CAN BE CLASSIFIED STRUCTURALLY
• a.ALVEOLAR (ACINAR)-BULB-LIKE
• b.TUBULAR
• c.TUBULOALVEOLAR

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SECRETORY UNITS CAN BE CLASSIFIED FUNCTIONALLY

• 1.MEROCRINE-EXOCYTOSIS EG.PANCREAS,SWEAT AND
  SALIVARY GLANDS
• 2.HOLOCRINE-FILL UNTIL THEY RUPTURE.PRODUCT WILL
  CONTAIN REMAINS OF CELLS. NEW GLAND WILL FORM
  FROM THE BASAL CELLS. EG. SEBACEOUS(OIL) GLANDS
• 3.APOCRINE-APEX OF EACH CELL PINCHES OFF AND
  RELEASES CONTENTS INTO THE GLAND EG.MAMMARY

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APROCRINEMAMMARY
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CONNECTIVE TISSUE

• FUNCTIONS
• 1.BINDING AND SUPPORT
• 2.PROTECTION
• 3.INSULATION
• 4.TRANSPORTATION
• COMMON CHARACTERISTICS
• 1.COMMON ORGIN-MESENCHYME-EMBRYONIC MESODERM
  LAYER
• 2.DEGREES OF VASCULARITY-MUSCLES/NERVES HIGH
  VASCULARITY CARTILAGE-AVASCULAR
• 3.EXTRACELLULAR MATRIX-NON-LIVING MATERIALS
  CONSISTING OF GROUND SUBSTANCE AND FIBERS

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CONNECTIVE TISSUE STRUCTURAL ELEMENTS

• 1.GROUND SUBSTANCE-PROTEINS THAT ARE STICKY,STIFF
  LIKE BRUSHES, OR ARE CAPABLE OF HOLDING AND
  TRAPPING WATER AND OTHER FLUIDS.

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2.FIBERS

• a.COLLAGEN-PROTEIN,WHITE FIBERS, FORM A FIBER
  MESH NETWORK
• STRONG, NOT VERY ELASTIC. GIVE STRENGTH TO
  TENDONS AND LIGAMENTS

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2.FIBERS, CONTD

• b.ELASTIC-COILED PROTEIN, ALLOWS STRETCH AND
  MAINTENANCE OF SHAPE, YELLOW FIBERS

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2.FIBERS, CONTD

• c.RETICULAR-FINE FIBERS THAT WORK WITH COLLAGEN
  TO FORM A MESH.MORE DELICATE- FUZZY NETS

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3. CELLS

• 3.CELLS-MAJOR CELL TYPES THAT PRODUCE AND
  SECRETE GROUND SUBSTANCE AND FIBERS.
• a.FIBROBLAST
• b.CHONDROBLAST
• c.OSTEOBLAST
• d.HEMOCYTOBLAST/HEMOPOIETIC STEM CELL

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OTHER CELLS

• OTHER CELLS
• FAT CELLS-NUTRIENT SUPPLIERS
• WHITE BLOOD CELLS-FIRST RESPONDERS TO INJURY
• MAST CELLS-SENTINELS
• MACROPHAGES-PHAGOCYTES
• PLASMA CELLS-ANTIBODY PRODUCERS

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OTHER CELLS, CONTD
PLASMA CELLS
MAST CELL
MACROPHAGE
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CONNECTIVE TISSUE TYPES

• 1.EMBRYONIC-MESENCHYME-STAR-SHAPED CELLS
  EX.WHARTONS JELLY

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CONNECTIVE TISSUE TYPES

• 2.CONNECTIVE TISSUE PROPER-LOOSE AND DENSE
• a.AREOLAR- GEL-LIKE MATRIX,W/FIBROBLASTS AND
  OTHER CELL TYPES. WRAPS AND PACKAGES ORGANS.PLAYS
  A ROLE IN INFLAMMATION.HOLDS AND CONVEYS EXCESS
  FLUID.ASSOCIATED W/EDEMA

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CONNECTIVE TISSUE TYPES

• b.ADIPOSE-FAT CELLS/ADIPOCYTES-SUPPORTS,PROVIDES
  RESERVE FUEL, INSULATES. FOUND UNDER SKIN,IN
  BREASTS AND ABDOMEN

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CONNECTIVE TISSUE TYPES

• c.RETICULAR-W/CELLS CAN FORM INTERNAL SKELETON IN
  SOME ORGANS SUCH AS SPLEEN

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CONNECTIVE TISSUE TYPES

• 3.DENSE REGULAR-MOSTLY PARALLEL COLLAGEN
  W/ELASTIN AND FIBROBLASTS,ATTACHES BONES TO
  MUSCLES TOGETHER OR BONES TO BONES.FOUND
  W/TENDONS AND LIGAMENTS.

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CONNECTIVE TISSUE TYPES

• 5.HYALINE CARTILAGE-GRISTLE CONTAINS COLLAGEN,
  HAS A GLASSY APPEARANCE, CONNECTS RIBS, END OF
  NOSE, LARYNX. PROVIDES SUPPORT WITH PLIABILITY

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6.ELASTIC CARTILAGE-LIKE HYALINE, BUT MORE
ELASTIC.EG.EXTERNAL EAR AND EPIGLOTTIS.
CONNECTIVE TISSUE TYPES
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CONNECTIVE TISSUE TYPES

• 7.FIBROCARTILAGE INTERMEDIATE BETWEEN BONE AND
  HYALINE CARTILAGE. CAN WITHSTAND HEAVY
  PRESSURE.EG. INVERTEBRAL DISCS IN SPINE AND
  CARTILAGE OF THE KNEE.

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CONNECTIVE TISSUE TYPES

• 8.BONE (OSSEOUS TISSUE)-PROVIDES SUPPORT, STORES
  FAT, SYNTHESIS OF RED BLOOD CELLS.THE CELLS OF
  THIS TISSUE ARE OSTEOBLASTS OSTEOCYTES.

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CONNECTIVE TISSUE TYPES

• 9.BLOOD-VARIETY OF CELLS SURROUNDED BY A MATRIX
  OF NON-LIVING MATERIAL.BLOOD FUNCTIONS AS THE
  TRANSPORT MECHANISM FOR NUTRIENTS, RESPIRATORY
  GASES, WASTES.

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EPITHELIAL MEMBRANES

• COMPOSED OF AT LEAST TWO PRIMARY TISSUE TYPES
• EPITHELIAL CELLS AND CONNECTIVE TISSUE
• TYPES
• 1.CUTANEOUS MEMBRANES-SKIN,KERATINIZED,STRATIFIED
  SQUAMOUS AND DENSE CONNECTIVE TISSUE, EXPOSED TO
  AIR, DRY MEMBRANE
• 2.MUCOUS MEMBRANES-DIGESTIVE, RESPIRATORY,
  UROGENITAL, LINE BODY CAVITIES, BUT OPEN TO
  EXTERIOR,WET MEMBRANES COMPOSED OF STRATIFIED
  SQUAMOUS OR SIMPLE COLUMNAR AND LOOSE CONECTIVE
  TISSUE(LAMINA PROPRIA),SOME HAVE A THIRD LAYER OF
  SMOOTH MUSCLE,SOME SECRETE MUCOUS,BUT NOT ALL DO.
• 3.SEROUS MEMBRANES-CLOSED BODY CAVITIES-
  PERICARDIUM,PLEURA,PERITONIUM,SIMPLE SQUAMOUS ON
  LOOSE CONNECTIVE TISSUE,SEROUS FLUID LUBRICATES
  LAYERS.

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MUSCLE TISSUEHIGHLY CELLULAR,ELONGATED,
MYOFILAMENTS OF ACTIN AND MYOSIN

• TYPES
• 1.SKELETAL-LONG,CYLINDRICAL CELLS W/MANY
  NUCLEI,ATTACHED TO BONES,FUNCTION-VOLUNTARY
  MOVEMENT

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MUSCLE TISSUE

• 2.CARDIAC-STRIATED,UNINUCLEATE,BRANCHING CELLS,
  TIGHTLY BOUND W/INTERCALATED DISCS,FOUND ONLY IN
  THE HEART,INVOLUNTARY CONTROL,FUNCTION-PUMPING
  BLOOD

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MUSCLE TISSUE

• 3.SMOOTH-NO STRIATIONS,SPINDLE-SHAPED,ONE
  NUCLEUS,FOUND ALONG WALLS OF HOLLOW ORGANS TO
  PROPEL SUBSTANCES, INVOLUNTARY.

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NERVOUS TISSUE

• 1.NEURONS-BRANCHING STELLATE CELLS FOUND IN
  BRAIN,SPINAL CHORD, AND NERVES.CONDUCT ELECTRICAL
  IMPULSES
• 2.SUPPORTING TISSUE-CELLS WHICH ARE
  NON-CONDUCTING, BUT SUPPORT AND INSULATE NEURONS

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TISSUE REPAIR

• HOW TISSUES ARE REPAIRED DEPENDS ON
• A.TYPE OF TISSUE DAMAGED
• B.SEVERITY OF INJURY
• C.NUTRITION
• D.ADEQUACY OF BLOOD SUPPLY
• E.AGE
• F.STATE OF HEALTH

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TYPES OF REPAIR

• 1.REGENERATION-REPLACEMENT OF DESTROYED TISSUE
• 2.FIBROSIS-PROLIFERATION OF FIBROUS CONNECTIVE
  TISSUE-SCAR TISSUE

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STEPS IN REPAIR

• 1.INFLAMMATION
• 2.ORGANIZATION
• 3.REGENERATION

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DEVELOPMENTAL ASPECTS OF TISSUES

• GERM LAYERS
• 1.ECTODERM-EPITHELIUM,BUT IT ARISES FROM MESODERM
  AND ENDODERM,TOO
• 2.MESODERM-MUSCLE,CONNECTIVE TISSUE
• 3.ENDODERM-NERVOUS TISSUE
• THE EFFECTS OF AGING
• MASS AND VIABLITY DECREASES W/AGE DUE TO
  NUTRITIONAL AND CIRCULATORY DEFICITS