Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Tissues: Living Communities Tissues: Living Communities
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Tissues: Living CommunitiesTissues: Living Communities
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Learning ObjectivesLearning Objectives Describe the functions of epithelial tissues.Describe the functions of epithelial tissues. Differentiate between the three major types of cellular junctions Differentiate between the three major types of cellular junctions
found between epithelial cells.found between epithelial cells. Describe the structure of the basement membrane.Describe the structure of the basement membrane. List and describe the characteristics used to classify different List and describe the characteristics used to classify different
epithelial tissues. epithelial tissues. List and describe the characteristics used to classify different List and describe the characteristics used to classify different
glands.glands. List and describe the components that make up connective tissues.List and describe the components that make up connective tissues. Differentiate between areolar, adipose, and reticular connective Differentiate between areolar, adipose, and reticular connective
tissues.tissues. Differentiate between dense regular, dense irregular, and elastic Differentiate between dense regular, dense irregular, and elastic
connective tissues.connective tissues. Differentiate between hyaline cartilage, elastic cartilage, and Differentiate between hyaline cartilage, elastic cartilage, and
fibrocartilage.fibrocartilage. List and describe the components of bone.List and describe the components of bone.
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Types of TissuesTypes of Tissues
Tissues are classified into the following Tissues are classified into the following four primary types:four primary types:1. Epithelial tissue1. Epithelial tissue
2. Connective tissue2. Connective tissue
3. Muscle tissue3. Muscle tissue
4. Nervous tissue4. Nervous tissue
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Epithelial TissuesEpithelial Tissues
Sheets of cells that cover and line other Sheets of cells that cover and line other tissuestissues
Protect underlying tissues and may act to Protect underlying tissues and may act to filter biochemical substancesfilter biochemical substances
May absorb, secrete, or excrete May absorb, secrete, or excrete biochemical substancesbiochemical substances
May play a role in the reception of sensory May play a role in the reception of sensory inputinput
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Characteristics of EpitheliaCharacteristics of Epithelia
Each epithelial cell has an apical surface Each epithelial cell has an apical surface and a basal surfaceand a basal surface Apical surface faces the lumen or outside of Apical surface faces the lumen or outside of
the organ the organ Basal surface faces the basal lamina and blood Basal surface faces the basal lamina and blood
vesselsvessels Lateral surfaces are connected to Lateral surfaces are connected to
neighboring cells by junctional complexes.neighboring cells by junctional complexes. Epithelial cells are avascular. Epithelial cells are avascular. Most epithelial cells are innervated.Most epithelial cells are innervated.
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Cellular AttachmentsCellular Attachments
Three major types of cellular junctions Three major types of cellular junctions
1. Tight junctions1. Tight junctions
2. Desmosomes2. Desmosomes
3. Gap junctions3. Gap junctions
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Tight JunctionsTight Junctions
Formed by the fusion Formed by the fusion of the outermost of the outermost layers of the plasma layers of the plasma membranes of membranes of adjoining cells adjoining cells
Found in tissues in Found in tissues in which there can be no which there can be no leaks (urinary bladder, leaks (urinary bladder, digestive tract) digestive tract)
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DesmosomesDesmosomes
Mechanical coupling Mechanical coupling formed by filaments that formed by filaments that interlock with one anotherinterlock with one another
Tonofilaments extend from Tonofilaments extend from the plaque into the the plaque into the cytoplasm.cytoplasm.
Found in tissues that Found in tissues that undergo repeated undergo repeated episodes of tension and episodes of tension and stretching (skin, heart, stretching (skin, heart, uterus) uterus)
Hemidesmosomes link Hemidesmosomes link epithelial cells to the epithelial cells to the basement membrane.basement membrane.
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Gap JunctionsGap Junctions Tubular channel proteins Tubular channel proteins
(connexons) that extend (connexons) that extend from the cytoplasm of from the cytoplasm of one cell to the cytoplasm one cell to the cytoplasm of another of another
Allow exchange and Allow exchange and passage of ions and passage of ions and nutrients nutrients
Found in intestinal Found in intestinal epithelial cells, the heart, epithelial cells, the heart, and smooth muscle and smooth muscle tissuetissue
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Basement MembraneBasement Membrane
Meshwork of fibers that cements the Meshwork of fibers that cements the epithelial cell to the underlying connective epithelial cell to the underlying connective tissue tissue
Also called Also called basal laminabasal lamina Varies in thickness Varies in thickness Helps prevent the cell from being torn off Helps prevent the cell from being torn off
by intraluminal pressuresby intraluminal pressures Acts as a partial barrier between the Acts as a partial barrier between the
epithelial cell and the underlying epithelial cell and the underlying connective tissueconnective tissue
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Surface SpecializationSurface Specialization Surfaces of epithelial Surfaces of epithelial
cellsvary depending on cellsvary depending on where they are located where they are located and what role they play in and what role they play in the function of the tissuethe function of the tissue SmoothSmooth Microvilli (brush Microvilli (brush
border)border) CiliaCilia Keratin.Keratin.
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Classification of Epithelial Tissue Classification of Epithelial Tissue
Number of layers of Number of layers of cells: Simple or cells: Simple or stratifiedstratified
Shape of the cells: Shape of the cells: Squamous, cuboidal, Squamous, cuboidal, and columnarand columnar
Presence of surface Presence of surface specializations: Cilia, specializations: Cilia, keratin, etc.keratin, etc.
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Simple Squamous EpitheliumSimple Squamous Epithelium
Fragile and thin Fragile and thin Found lining surfaces Found lining surfaces
involved in the passage involved in the passage
of either gas or liquid of either gas or liquid Flat and smoothFlat and smooth
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Simple Cuboidal Epithelium Simple Cuboidal Epithelium
Single layer of cube-Single layer of cube-shaped cells shaped cells
Round, dark-stainingRound, dark-stainingnuclei aligned nuclei aligned
in a single row in a single row Occurs in areas of the Occurs in areas of the
body where secretionbody where secretion and absorption and absorption
take placetake place
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Simple Columnar Epithelium Simple Columnar Epithelium
Elongated and closely Elongated and closely packed togetherpacked together
Nuclei aligned in a Nuclei aligned in a row at the base of the row at the base of the cell near the cell near the basement membranebasement membrane
Found in many Found in many excretory ducts as excretory ducts as well as in the digestive well as in the digestive tracttract
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Stratified Squamous EpitheliumStratified Squamous Epithelium
Multilayered Multilayered Occur in areas of the Occur in areas of the
body subject to mechanical body subject to mechanical
and chemical stressesand chemical stresses Protect underlying Protect underlying
tissuestissues
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Stratified Cuboidal EpitheliumStratified Cuboidal Epithelium
Usually two layers of Usually two layers of cuboidal cellscuboidal cells
Found primarily along large Found primarily along large excretory ductsexcretory ducts
Protects underlying tissuesProtects underlying tissues
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Stratified Columnar EpitheliumStratified Columnar Epithelium
Found only in select parts Found only in select parts of the respiratory, digestive,of the respiratory, digestive,reproductive systems and reproductive systems and along some excretory ductsalong some excretory ducts
Function in secretion Function in secretion
and protectionand protection
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Pseudostratified Columnar Pseudostratified Columnar EpitheliumEpithelium
Cell nuclei are found at different Cell nuclei are found at different
levels across the length of the levels across the length of the tissuetissue
Some cells do not reach the Some cells do not reach the
luminal surface luminal surface Found in respiratory tract and Found in respiratory tract and
in portions of the male in portions of the male
reproductive tractreproductive tract
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Transitional EpitheliumTransitional Epithelium
Stratified epithelium with a basal Stratified epithelium with a basal layer of cuboidal or columnar layer of cuboidal or columnar cells and a superficial layer of cells and a superficial layer of cuboidal or squamous cellscuboidal or squamous cells
Found in areas of the body Found in areas of the body required to expand and contract required to expand and contract as part of their normal functionas part of their normal function
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Glandular EpitheliumGlandular Epithelium Groups of cells that Groups of cells that
manufacture and discharge a manufacture and discharge a secretionsecretion
Classification of glandsClassification of glands1.1. Presence or absence of ducts Presence or absence of ducts
2.2. Number of cells that compose Number of cells that compose them them
3.3. Shape of the secreting ductsShape of the secreting ducts
4.4. Complexity of the glandular Complexity of the glandular structurestructure
5.5. Type of secretion they produceType of secretion they produce
6.6. Manner in which the secretion is Manner in which the secretion is stored and dischargedstored and discharged
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Endocrine GlandsEndocrine Glands
Glands that do not have ducts or tubules Glands that do not have ducts or tubules and whose secretions are distributed and whose secretions are distributed throughout the bodythroughout the body
Produce and secrete Produce and secrete hormones hormones into the into the bloodstream or the lymphatic systembloodstream or the lymphatic system
Part of a complex, biochemical network Part of a complex, biochemical network known as the endocrine systemknown as the endocrine system
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Exocrine GlandsExocrine Glands
Discharge secretions via ducts directly into Discharge secretions via ducts directly into local areas (except for goblet cell)local areas (except for goblet cell)
Unicellular or multicellularUnicellular or multicellular
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Goblet CellGoblet Cell
Unicellular exocrine Unicellular exocrine gland gland
Ductless and composed Ductless and composed of modified columnar of modified columnar epithelial cell epithelial cell
Found among columnar Found among columnar cells of the respiratory cells of the respiratory and digestive tracts and and digestive tracts and the conjunctiva of the the conjunctiva of the eye eye
Secretes mucinSecretes mucin
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Multicellular Exocrine GlandsMulticellular Exocrine Glands
Composed of a secretory unit and a duct Composed of a secretory unit and a duct Secretory unit is usually surrounded by Secretory unit is usually surrounded by
connective tissue rich in blood vessels and connective tissue rich in blood vessels and nerve fibers nerve fibers
May be surrounded by myoepithelial cells May be surrounded by myoepithelial cells that assist with the discharge of secretions that assist with the discharge of secretions into the glandular ductinto the glandular duct
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Classification of Exocrine GlandsClassification of Exocrine Glands
Ducts:Ducts: Simple: main duct is unbranched Simple: main duct is unbranched Compound: main duct is branchedCompound: main duct is branched
Shape of secretory portions Shape of secretory portions Tubular: secretory cells form a long channel of Tubular: secretory cells form a long channel of
even widtheven width Alveolar or acinar: secretory unit forms a Alveolar or acinar: secretory unit forms a
rounded sacrounded sac Tubuloalveolar, or tubuloacinar: secretory units Tubuloalveolar, or tubuloacinar: secretory units
possess both tubular and alveolar qualitiespossess both tubular and alveolar qualities
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Classification of Exocrine GlandsClassification of Exocrine Glands
MerocrineMerocrine glands glands package their package their secretions and release secretions and release them via exocytosis as them via exocytosis as they are manufactured. they are manufactured.
ApocrineApocrine glands store glands store their secretions and their secretions and then release the top then release the top part of the cell into the part of the cell into the duct systemduct system
HolocrineHolocrine glands store glands store their secretions and their secretions and then release the entire then release the entire contents of the cellcontents of the cell
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Classification of Exocrine GlandsClassification of Exocrine Glands
Type of secretion producedType of secretion produced Serous secretions Serous secretions
Watery Watery Contain a high concentration of enzymesContain a high concentration of enzymes
Mucous secretionsMucous secretions Thick, viscousThick, viscous Composed of glycoproteins. Composed of glycoproteins.
Mixed exocrine glands contain both Mixed exocrine glands contain both mucousmucous and serous components.and serous components.
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Connective TissueConnective Tissue
FunctionsFunctions Forms metabolic and structural connections Forms metabolic and structural connections
between other tissuesbetween other tissues Forms a protective sheath around organs and Forms a protective sheath around organs and
helps insulate the bodyhelps insulate the body Acts as a reserve for energyActs as a reserve for energy Provides the frame that supports the bodyProvides the frame that supports the body Composes the medium that transports Composes the medium that transports
substances from one region of the body to substances from one region of the body to another another
Plays a role in the healing process and in the Plays a role in the healing process and in the control of invading microorganismscontrol of invading microorganisms
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Connective Tissue ComponentsConnective Tissue Components
Extracellular matrixExtracellular matrix Extracellular fibersExtracellular fibers Ground substanceGround substance
Cells Cells
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Connective Tissue ComponentsConnective Tissue Components
Ground substanceGround substance Medium through which cells exchange nutrients Medium through which cells exchange nutrients
and waste with the bloodstreamand waste with the bloodstream Amorphous, homogeneous material Amorphous, homogeneous material Ranges in texture from a liquid or gel to a Ranges in texture from a liquid or gel to a
calcified solidcalcified solid Acts to protect the more delicate cells it Acts to protect the more delicate cells it
envelopesenvelopes Serves as an effective obstacle for invading Serves as an effective obstacle for invading
microorganismsmicroorganisms
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Connective Tissue ComponentsConnective Tissue Components
Extracellular fibersExtracellular fibers Collagenous fibersCollagenous fibers
Strong, thick strands of collagenStrong, thick strands of collagen Organized into bundles of long, parallel fibrils Organized into bundles of long, parallel fibrils
composed of bundled microfibrilscomposed of bundled microfibrils Variable density and arrangement of fibersVariable density and arrangement of fibers Found in tendons and ligaments Found in tendons and ligaments
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Connective Tissue ComponentsConnective Tissue Components
Extracellular fibersExtracellular fibers Reticular fibersReticular fibers
Thin, delicate, branched networks of collagenThin, delicate, branched networks of collagen Provide support for highly cellular organs (endocrine Provide support for highly cellular organs (endocrine
glands, lymph nodes, spleen, bone marrow, and liver) glands, lymph nodes, spleen, bone marrow, and liver) Also found around blood vessels, nerves, muscle fibers, Also found around blood vessels, nerves, muscle fibers,
and capillariesand capillaries
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Extracellular fibersExtracellular fibers Elastic fibers Elastic fibers
Branched networks composed primarily of the protein Branched networks composed primarily of the protein elastinelastin
Composed of coiled bundles of microfibrilsComposed of coiled bundles of microfibrils Occur in tissues commonly subjected to stretching Occur in tissues commonly subjected to stretching
(vocal cords, lungs, skin, and walls of blood vessels)(vocal cords, lungs, skin, and walls of blood vessels)
Connective Tissue ComponentsConnective Tissue Components
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Connective Tissue ComponentsConnective Tissue Components
Cell TypesCell Types Fixed Cells: involved in production and Fixed Cells: involved in production and
maintenance of the matrixmaintenance of the matrix Fibroblasts, chondroblasts, osteoblasts, adipocytes, Fibroblasts, chondroblasts, osteoblasts, adipocytes,
reticular cellsreticular cells Transient Cells: involved in the repair and Transient Cells: involved in the repair and
protection of tissuesprotection of tissues Leukocytes, mast cells, macrophagesLeukocytes, mast cells, macrophages
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Connective Tissue ProperConnective Tissue Proper
Loose connective tissue Loose connective tissue AreolarAreolar AdiposeAdipose ReticularReticular
Dense connective tissue Dense connective tissue Dense regularDense regular Dense irregularDense irregular ElasticElastic
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Areolar Connective TissueAreolar Connective Tissue
Loose connective tissue Loose connective tissue Fibers and cells suspended in a Fibers and cells suspended in a
thick, translucent ground substance thick, translucent ground substance Predominant cell is the fibroblastPredominant cell is the fibroblast
Manufactures the elastic, reticular, Manufactures the elastic, reticular, and collagenous fibersand collagenous fibers
Surrounds every organ; forms the SQ Surrounds every organ; forms the SQ layer that connects skin to muscle; layer that connects skin to muscle; envelopes blood vessels, nerves, envelopes blood vessels, nerves, and lymph nodes; present in all and lymph nodes; present in all mucous membranesmucous membranes
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Adipose TissueAdipose Tissue
Loose connective tissueLoose connective tissue Areolar tissue in which Areolar tissue in which
adipocytes predominate adipocytes predominate Highly vascularHighly vascular Acts as an energy Acts as an energy
storehouse and a thermal storehouse and a thermal insulator insulator
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Reticular Connective TissueReticular Connective Tissue
Loose connective tissue Loose connective tissue Network of thin reticular Network of thin reticular
fibers. fibers. Contains loosely arranged Contains loosely arranged
fibers and many fibroblasts fibers and many fibroblasts suspended in a supportive suspended in a supportive ground substanceground substance
Forms the stroma Forms the stroma (framework of several (framework of several organs)organs)
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Dense Regular Connective TissueDense Regular Connective Tissue
Composed of tightly Composed of tightly packed, parallel packed, parallel collagen fibers collagen fibers
Relatively avascular Relatively avascular Makes up the tendons Makes up the tendons
and ligaments and ligaments Can be found in fascial Can be found in fascial
sheets that cover musclessheets that cover muscles
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Dense Irregular Connective TissueDense Irregular Connective Tissue
Composed primarily of collagen Composed primarily of collagen fibers arranged in thick bundles fibers arranged in thick bundles
Fibers are interwoven to form a Fibers are interwoven to form a single sheet single sheet
Found in the dermis of the skin Found in the dermis of the skin and in the fibrous coverings of and in the fibrous coverings of many organsmany organs
Forms the tough capsule of jointsForms the tough capsule of joints
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Elastic Connective TissueElastic Connective Tissue
Primarily composed of elastic fibersPrimarily composed of elastic fibers Fibers may be arranged parallel or in Fibers may be arranged parallel or in
interwoven patterns with fibroblasts and interwoven patterns with fibroblasts and collagenous fibers interspersedcollagenous fibers interspersed
Found in spaces between vertebrae and in Found in spaces between vertebrae and in areas of the body that require stretching areas of the body that require stretching (walls of arteries, stomach, bronchi, (walls of arteries, stomach, bronchi, bladder, etc.)bladder, etc.)
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Specialized Connective TissuesSpecialized Connective Tissues
CartilageCartilage Hyaline cartilageHyaline cartilage Elastic cartilageElastic cartilage FibrocartilageFibrocartilage
BoneBone BloodBlood
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CartilageCartilage
Found in joints and in the ear, nose, and vocal Found in joints and in the ear, nose, and vocal cords cords
Forms a framework on which bone is formedForms a framework on which bone is formed No innervation; avascularNo innervation; avascular Cells:Cells:
Chondrocytes: live in hollowed-out pockets in the matrix Chondrocytes: live in hollowed-out pockets in the matrix called called lacunaelacunae
Matrix:Matrix: Ground substance: gel of chondroitin sulfate, hyaluronic Ground substance: gel of chondroitin sulfate, hyaluronic
acid, and chondronectin acid, and chondronectin Collagen fibers are most commonly found in the matrix, Collagen fibers are most commonly found in the matrix,
but elastic fibers are also present in varying amounts.but elastic fibers are also present in varying amounts.
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Hyaline CartilageHyaline Cartilage Most common type of cartilage Most common type of cartilage
found in the bodyfound in the body Composed of closely packed Composed of closely packed
collagen collagen FoundFound in jointsin joints at the ends of long at the ends of long
bones, growth plates of long bones, bones, growth plates of long bones, tracheal rings, and connections of tracheal rings, and connections of the ribs to the sternum the ribs to the sternum
Composes most of the embryonic Composes most of the embryonic skeleton Enclosed within a skeleton Enclosed within a perichondriumperichondrium
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Elastic CartilageElastic Cartilage
Contains elastic fibers in Contains elastic fibers in dense branching bundles dense branching bundles
Flexible: can withstand Flexible: can withstand repeated bending repeated bending
Found in the epiglottis of the Found in the epiglottis of the larynx and in pinnae of ears larynx and in pinnae of ears of animalsof animals
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FibrocartilageFibrocartilage Usually found merged with hyaline Usually found merged with hyaline
cartilage and dense connective cartilage and dense connective tissue tissue
Contains thick bundles of collagen Contains thick bundles of collagen fibers with fewer chondrocytes fibers with fewer chondrocytes than hyaline cartilagethan hyaline cartilage
Lacks a perichondrium Found in Lacks a perichondrium Found in spaces between vertebrae of the spaces between vertebrae of the spine, between bones in the pelvic spine, between bones in the pelvic girdle, and in the knee jointgirdle, and in the knee joint
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BoneBone
Matrix is a combination of organic Matrix is a combination of organic collagen fibers and inorganic collagen fibers and inorganic calcium saltscalcium salts
Well vascularizedWell vascularized Haversian canal contains both a Haversian canal contains both a
vascular and a nerve supply vascular and a nerve supply Canaliculi: channels within the Canaliculi: channels within the
matrix support passage of blood matrix support passage of blood vessels into deeper portions vessels into deeper portions of tissue of tissue
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BoneBone
Osteoblasts: manufacture the fibers Osteoblasts: manufacture the fibers that are part of the matrixthat are part of the matrix Lacunae and canaliculi are Lacunae and canaliculi are
created as the osteoblasts created as the osteoblasts manufacture the bony matrix. manufacture the bony matrix.
Osteocytes reside in lacunae. Osteocytes reside in lacunae. Cellular extensions pass Cellular extensions pass
through the canaliculi.through the canaliculi.
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BloodBlood
Matrix: Matrix: Ground substance: plasma Ground substance: plasma fibrous component: protein fibrous component: protein
CellsCells Erythrocytes Erythrocytes Leukocytes Leukocytes ThrombocytesThrombocytes
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Mucous MembranesMucous Membranes
Mucous membranes (mucosae)Mucous membranes (mucosae) Line organs with connections to the outside environment Line organs with connections to the outside environment
(mouth, intestines, nasal passages, etc.)(mouth, intestines, nasal passages, etc.) Usually composed of either stratified squamous or simple Usually composed of either stratified squamous or simple
columnar epithelium covering a layer of loose connective columnar epithelium covering a layer of loose connective tissue tissue
Submucosa : connective tissue layer that connects the Submucosa : connective tissue layer that connects the mucosa to underlying structuresmucosa to underlying structures
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Mucous MembranesMucous Membranes
Mucous membranes (mucosae)Mucous membranes (mucosae) May contain goblet cells or multicellular glands May contain goblet cells or multicellular glands
Can produce large quantities of mucus Can produce large quantities of mucus Mucus consists primarily of water, electrolytes, and the protein Mucus consists primarily of water, electrolytes, and the protein
mucinmucin Some mucosae also can absorb (e.g., the epithelial layer in Some mucosae also can absorb (e.g., the epithelial layer in
the intestine)the intestine)
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Serous MembranesSerous Membranes
Serous membranesSerous membranes (serosae)(serosae) Line walls and cover organs of body cavities (e.g., thorax and Line walls and cover organs of body cavities (e.g., thorax and
abdominopelvic cavities) abdominopelvic cavities) Consist of a continuous sheet doubled over on itself to form two Consist of a continuous sheet doubled over on itself to form two
layers layers The portion of the membrane that lines the cavity wall is called theThe portion of the membrane that lines the cavity wall is called the
parietal layer.parietal layer. The portion of the membrane that covers the outer surface of The portion of the membrane that covers the outer surface of
organs is called theorgans is called the visceral layer. visceral layer. In abdominopelvic cavity, visceral layers of serosa merge to form In abdominopelvic cavity, visceral layers of serosa merge to form
mesenteries.mesenteries.
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Cutaneous MembraneCutaneous Membrane
Also called Also called integumentintegument (or, more simply, (or, more simply, skinskin) ) Composed of an outer keratinized stratified Composed of an outer keratinized stratified
squamous epithelium, or squamous epithelium, or epidermisepidermis Epidermis is attached to an underlying layer of Epidermis is attached to an underlying layer of
dense irregular connective tissue called the dense irregular connective tissue called the dermisdermis. .
Dermis contains collagenous, reticular, and elastic Dermis contains collagenous, reticular, and elastic fibers which enable skin to be both strong and fibers which enable skin to be both strong and elasticelastic
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Synovial MembranesSynovial Membranes
Line the cavities of joints Line the cavities of joints Composed of loose connective tissue and Composed of loose connective tissue and
adipose tissue covered by a layer of adipose tissue covered by a layer of collagen fibers and fibroblasts collagen fibers and fibroblasts
Manufacture the synovial fluid that fills the Manufacture the synovial fluid that fills the joint spacesjoint spaces
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Muscle TissueMuscle Tissue
Composed of actin and myosin fibersComposed of actin and myosin fibers Three types of muscle tissueThree types of muscle tissue
SkeletalSkeletal SmoothSmooth CardiacCardiac
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Skeletal MuscleSkeletal Muscle Large cells that contain hundreds of nuclei Large cells that contain hundreds of nuclei
and mitochondriaand mitochondria Usually controlled through conscious efforts Usually controlled through conscious efforts
(voluntary muscle)(voluntary muscle) Skeletal muscle cells are striated.Skeletal muscle cells are striated. Skeletal muscle cells are bundles of fibers Skeletal muscle cells are bundles of fibers
held together by loose connective tissue. held together by loose connective tissue. The collagen fibers that surround the cells The collagen fibers that surround the cells
merge with merge with the collagen fibers in tendons.the collagen fibers in tendons.
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Smooth MuscleSmooth Muscle Composed of small, spindle-shaped cells Composed of small, spindle-shaped cells
that lack striationsthat lack striations Muscle contractions cannot be consciously Muscle contractions cannot be consciously
controlled (nonstriated involuntary muscle)controlled (nonstriated involuntary muscle) Found in the walls of hollow organs, in Found in the walls of hollow organs, in
exocrine glands, and along the exocrine glands, and along the respiratory tract respiratory tract Responsible for Responsible for peristalsisperistalsis in in
gastrointestinal tract, constriction gastrointestinal tract, constriction of blood vessels, and emptying of of blood vessels, and emptying of urinary bladderurinary bladder
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Cardiac MuscleCardiac Muscle
Found only in the heart Found only in the heart Contains specialized pacemaker cells Contains specialized pacemaker cells
that supply signal for heart to contract that supply signal for heart to contract at regular intervals at regular intervals
Entirely involuntary and striatedEntirely involuntary and striated Cardiac muscle cells connected to Cardiac muscle cells connected to
one another via one another via intercalated disksintercalated disks
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Nervous TissueNervous Tissue
Found in the brain, spinal cord, and Found in the brain, spinal cord, and peripheral nerves peripheral nerves
Composed of two general cell types:Composed of two general cell types: Neurons Neurons Supporting neuroglial cellsSupporting neuroglial cells
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Nervous TissueNervous Tissue
NeuronsNeurons Longest cells in the body; Longest cells in the body;
three primary parts:three primary parts: PerikaryonPerikaryon – the cell body; – the cell body;
contains the nucleuscontains the nucleus DendritesDendrites –– short cytoplasmic short cytoplasmic
extensions; receives impulsesextensions; receives impulses AxonsAxons –– long, single extension; long, single extension;
conducts impulses away from conducts impulses away from the cell bodythe cell body
Neuroglial cellsNeuroglial cells Support the neuronsSupport the neurons
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Tissue Healing and RepairTissue Healing and Repair
Inflammation: initial response to injuries Inflammation: initial response to injuries Goal: limit further damage and eliminate any Goal: limit further damage and eliminate any
harmful agents harmful agents Repair: involves organization of Repair: involves organization of
granulation tissue and regeneration of lost granulation tissue and regeneration of lost tissue or formation of scar tissuetissue or formation of scar tissue
Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc.
InflammationInflammation Nonspecific reaction Nonspecific reaction
to injury or diseaseto injury or disease StepsSteps
1.1. VasodilationVasodilation
2.2. SwellingSwelling
3.3. Clot formationClot formation
4.4. PhagocytosisPhagocytosis
5.5. Capillaries return to Capillaries return to normal size, blood normal size, blood flow and fluid leakage flow and fluid leakage into the affected area into the affected area abateabate
Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc.
Formation of Granulation Tissue and Formation of Granulation Tissue and EpithelializationEpithelialization
Tissue that forms Tissue that forms beneath the beneath the overlying blood clot overlying blood clot or scab or scab
Composed of a layer Composed of a layer of collagen fibers of collagen fibers infiltrated with infiltrated with capillaries (that have capillaries (that have branched off existing branched off existing capillaries in deeper capillaries in deeper layers of damaged layers of damaged tissue)tissue)
Granulation tissue is Granulation tissue is slowly replaced by slowly replaced by fibrous scar tissue.fibrous scar tissue.
Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc.
Classification of Wound HealingClassification of Wound Healing
First intentionFirst intention:: Edges of wound held in close apposition Edges of wound held in close apposition Skin forms a primary union without formation of Skin forms a primary union without formation of
granulation tissue or significant scarringgranulation tissue or significant scarring Second intentionSecond intention: :
Edges of wound separated from each anotherEdges of wound separated from each another Granulation tissue forms to close gap; scarring resultsGranulation tissue forms to close gap; scarring results
Third intentionThird intention:: Contaminated wound left open until contamination is Contaminated wound left open until contamination is
reduced and inflammation subsides; later closed by reduced and inflammation subsides; later closed by firstfirst intentionintention; also called ; also called delayed primary closuredelayed primary closure