Biol 432 PP Connective Tissues

8/4/2019 Biol 432 PP Connective Tissues

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CONNECTIVECONNECTIVECONNECTIVECONNECTIVECONNECTIVECONNECTIVECONNECTIVECONNECTIVETISSUESTISSUESTISSUESTISSUESTISSUESTISSUESTISSUESTISSUES



CONNECTIVE TISSUES



CONNECTIVE TISSUES

!!!! TYPICALLY CONTAIN AN EXTENSIVE

EXTRACELLULAR COMPARTMENTand A REDUCED CELLULAR COMPARTMENTRELATIVE TO OTHER TISSUES

!!!! CHARACTERIZED BY WIDELY SPACED CELLSand EXTENSIVE EXTRACELLULAR MATERIALS



BASIC COMPONENTS OF

CONNECTIVE TISSUES

CELLULAR COMPARTMENT

!!!! RESIDENT/PERMANENT CELLS

!!!! TRANSIENT CELLS

!!!! “OTHER” CELLS

EXTRACELLULAR COMPARTMENT

!!!! EXTRACELLULAR MATRIX COMPONENTSFormed/Fibrous ComponentsAmorphous Components

!!!! TISSUE FLUID



EXTRACELLULAR MATRIXCOMPONENTS

OF CONNECTIVE TISSUE

!!!! FORMED/FIBROUS COMPONENTS

!!!! AMORPHOUS COMPONENTS



COMPONENTS OF CONNECTIVE TISSUE

(in post-natal vertebrates)

EXTRA-CELLULAR COMPARTMENT

Formed/ Fibrous Material

Collagen Fibers (type I or type II)Reticular Fibers (type IIIcollagen)Elastic FibersExtracellular

Matrix

ComponentsAmorphous Material/ "Ground" Substance

Glycosaminoglycans (GAGs)GlycoproteinsProteoglycansProteoglycan Aggregrates

Tissue FluidSimilar to blood plasma(minus many plasma proteins)



FORMED/FIBROUSECM COMPONENTS

of Connective Tissues

!!!! COLLAGEN FIBERS(composed of type I [most CT] or type II

[cartilage] collagen)

!!!! RETICULAR FIBERS

(composed of type III collagen)

!!!! ELASTIC FIBERS

(composed of elastin)



FIBROUS ECM COMPONENTS

Source: Kelly et al. 1984. Bailey’s Textbook of Microscopic Anatomy. 18th Edition.

CollagenFiber

CollagenFiber



Source: Figure 5.12 in Ross et al. 1995. Histology. 3rd Edition.

Type ICollagen Fibers

Cytoplasm of FibroblastNucleus of Fibroblast

Cytoplasmof Fibroblast

Cytoplasmof Fibroblast

Cytoplasm of Fibroblast

COLLAGEN FIBERSAs Viewed at LM Level



COLLAGEN FIBERS & FIBRILSAs Viewed at TEM Level

Source: Rhodin. 1974. Histology. A Text & Atlas.

Collagen Fiber Collagen Fibril






ReticularFiber

Source: Junqueira et al. 1975. Basic Histology.

ReticularFiber





Elastic

Fiber

Elastic

Fiber



ELASTIC FIBERS(as observed at TEM level)



AMORPHOUS ECM COMPONENTS

of Connective Tissues!!!! PROTEINS/GLYCOPROTEINS

!!!! GLYCOSAMINOGLYCANS/GAGSHyaluronic Acid

Chondroitin Sulfate

Keratan SulfateDermatan SulfateHeparan Sulfate

Heparin!!!! PROTEOGLYCANS and

PROTEOGLYCAN AGGREGATES!!!! MINERALS





AmorphousComponents



EXTRACELLULAR MATRIX

MACROMOLECULES

Source: Alberts et al. 1994.Molecular Biology of the Cell.3rd Edition.



EXTRACELLULAR MATRIX COMPONENTS

ARE EXTENSIVELY INTERCONNECTED

(as shown here in basal lamina)

Source: Figure 19-56 in Alberts et al. 1994. Molecular Biology of Cell. 3rd Edition.







AmorphousComponents

are locatedaround thefibers and

cells



COMPONENTS OF THE

CELLULAR COMPARTMENT OFCONNECTIVE TISSUE

!!!! RESIDENT or PERMANENT CELLS

!!!! TRANSIENT CELLS!!!! “OTHER” CELLS



RESIDENT/PERMANENT CT CELLS

!!!! MATRIX-”FORMING” CELLSDesignated by suffix -blast

!!!! MATRIX-“MAINTAINING” CELLS

Designated by suffix -cyte

!!!! MATRIX-”REMOVING” CELLS

Designated by suffix -clast

!!!! STORAGE CELLS



Most CT cells are derived developmentally

from MESENCHYME CELLS of embryo

Nucleus (N) & Cytoplasm (C)of

MESENCHYME CELLS (MeC)As Viewed at LM Level

Source: Gartner & Hiatt. 1994.

Color Atlas of Histology. 2nd Edition.



COMPONENTS OF CONNECTIVE TISSUE(in post-natal vertebrates)

CELLULAR COMPARTMENT

Matrix-"forming" Cells/

Matrix-"maintaining" Cells

Fibroblasts/FibrocytesReticular Cells

Chondroblasts/ChondrocytesOsteoblasts/Osteocytes

Matrix-"removing" Cells Osteoclasts

Resident CellsorPermanent Cells

Storage CellsUnilocular (White) Adipocytes

Multilocular (Brown) Adipocytes

Transient Cells

MacrophagesNeutrophilsEosinophils

T LymphocytesB LymphocytesPlasma Cells

Other Cells Mast CellsPericytes/Perivascular Cells



CYTOPLASMIC

PROCESS of

FIBROBLAST

NUCLEUS

of FIBROBLAST

COLLAGEN

FIBRILS

FIBROBLAST(as observed at TEM level)




FIBROBLASTAs Viewed at TEM Level

Source: Lentz. 1971. Cell Fine Structure.

Collagen Fibers





RETICULAR CELLS

ReticularCell


ReticularCell

RETICULAR CELL



RETICULAR CELLAs Observed at TEM Level




CHONDROBLASTS & CHONDROCYTESAs Viewed at TEM Level


Chondrocyte

Chondroblast

Collagen Fibrils

CHONDROCYTE



CHONDROCYTEAs Viewed at TEM Level


CHONDROCYTES s rro nded b ECM



CHONDROCYTES surrounded by ECMAs Viewed at LM Level

CHONDROCYTES surrounded by ECM



CHONDROCYTES surrounded by ECM

As Viewed at LM Level As Viewed at TEM Level

OSTEOBLASTS & OSTEOCYTES surrounded by ECM



OSTEOBLASTS & OSTEOCYTES surrounded by ECMAs Viewed at LM Level

Osteoblast

Osteocyte



OSTEOCYTE



OSTEOCYTE(surrounded by ECM)

As Viewed at TEM Level




OSTEOCLAST

As Viewed at LM Level

Ruffled borderof Osteoclast

Source: Burkitt et al. 1979. Wheater’s Functional Histology. 3rd Edition.



OSTEOBLASTS (A) and

OSTEOCLAST (B)As Viewed at LM Level

DIFFERENTIATION OF



DIFFERENTIATION OF

ADIPOCYTE/LIPOCYTES

UNILOCULAR ADIPOCYTE (white adipose cell)



UNILOCULAR ADIPOCYTE (white adipose cell)


LIPID DROPLET

As Viewed at LM LevelAs Viewed at TEM Level

MULTILOCULAR ADIPOCYTE (brown adipose cell)



MULTILOCULAR ADIPOCYTE (brown adipose cell)


LD

LD

LD

LD

LD

LD

LD

As Viewed at TEM Level As Viewed at LM Level



TRANSIENT CELLS OFCONNECTIVE TISSUE

!!!! MACROPHAGES

!!!! LYMPHOCYTES

!!!! PLASMA CELLS

!!!! NEUTROPHILS

!!!! EOSINOPHILS

MACROPHAGES/HISTOCYTES



MACROPHAGES/HISTOCYTES

nnnn DERIVED FROM MONOCYTES

nnnnHAVE IMPORTANT ROLES IN BODILYDEFENSE MECHANISMS

Active in phagocytosis

Synthesize & secrete cytokinesStimulate immune responses

TYPES OF MACROPHAGES



TYPES OF MACROPHAGES

FIXED

(nonmigratory)MACROPHAGE

FREE(migratory)

MACROPHAGE

Modified from: Kelly et al. 1984. Bailey’s Textbook of Microscopic Anatomy. 18th Edition.

ACTIVATED MACROPHAGE



ACTIVATED MACROPHAGEAs Viewed at TEM Level


1o Lysosomes

2o

Lysosomes

FIXED MACROPHAGES/HISTOCYTES




←←←← M

↑↑↑↑M

M

↓↓↓↓

M - nucleus of fixed macrophage (smaller, darker)

F↓↓↓↓

F

↓↓↓↓

F - nucleus of fibroblast (larger, lighter)

LYMPHOCYTES



LYMPHOCYTES

Source: Bloom & Fawcett. 1975. A Textbook of Histology. 10th Edition.


PLASMA CELL




As Viewed at TEM LevelAs Viewed at LM Level

Source: Bloom & Fawcett. 1975.A Textbook of Histology. 10th Edition.

NEUTROPHILS



NEUTROPHILS



EOSINOPHILS



EOSINOPHILS





Smooth

Muscle

Plasma Cells

LymphocyteMacrophage

Fibroblast



“OTHER” CELLS OFCONNECTIVE TISSUE

!!!! MAST CELLS

!!!!PERICYTES/PERIVASCULAR CELLS

MAST CELL




As Viewed at LM Level As Viewed at TEM Level

PERICYTE/PERIVASCULAR CELL



As Viewed at TEM Level


Endothelium

Pericyte surroundingEndothelium

PERICYTES/PERIVASCULAR CELLS





TYPES OF RESIDENT AND TRANSIENT CELLSFOUND IN CONNECTIVE TISSUES



FOUND IN CONNECTIVE TISSUES

Macrophage

Fibroblast

Lymphocyte


Macrophage

TYPES OF RESIDENT AND TRANSIENT CELLSFOUND IN CONNECTIVE TISSUES





FibroblastsPlasma CellEosinophil

Fibroblast

Lymphocyte

TYPES OF RESIDENT, TRANSIENT, AND “OTHER” CELLSFOUND IN CONNECTIVE TISSUES





Fibroblast

MacrophageMast Cells

Loose FECT



M

M

CONNECTIVE TISSUES



CONNECTIVE TISSUES

ARE CLASSIFIED/DESCRIBEDACCORDING TO

!!!! TYPE OF RESIDENT/PERMANENT CELLS

!!!! TYPE, AMOUNT, AND ORGANIZATIONOF ECM COMPONENTS

EMBRYONIC TYPES OF



EMBRYONIC TYPES OF

CONNECTIVE TISSUES

!!!! MESENCHYMAL CT

!!!! MUCOUS CT

Found only in embryos and prenatalvertebratesCharacterized by mesenchyme cells orimmature fibroblasts and lack of well-

developed fibrous ECM

Most CT cells are derived developmentally



from MESENCHYME CELLS of embryo

Nucleus (N) & Cytoplasm (C)of

MESENCHYME CELLS (MeC)As Viewed at LM Level

Source: Gartner & Hiatt. 1994.

Color Atlas of Histology. 2nd Edition.

Mucous Connective Tissue





Note increased fibersize and morefrequent stellate cellshapes in MucousCT

FIBROELASTIC TYPES OF



CONNECTIVE TISSUES!!!! LOOSE FECT

!!!! MODERATELY DENSE FECT

!!!! DENSE IRREGULAR FECT

!!!! DENSE REGULAR FECT

All are characterized by:Fibroblasts as resident matrix-”forming” cellsType I collagen fibers and elastic fibers as

major ECM components

Loose FECT





Dense Irregular FECT



“SPECIALIZED” FIBROUS TYPES



OF CONNECTIVE TISSUES

!!!!DENSE REGULAR COLLAGENOUS CT

!!!! DENSE REGULAR ELASTIC CT

Both are characterized by:Fibroblasts as resident matrix-”forming” cellsFibrous components arranged in denseparallel arrays

Dense Regular Collagenous CT






“SPECIALIZED” CELLULAR TYPES



OF CONNECTIVE TISSUES

!!!!WHITE ADIPOSE CT

!!!! BROWN ADIPOSE CT

!!!! RETICULAR CT

All are characterized by:

Much larger cellular compartmentcontaining characteristic cell populationsMuch reduced extracellular compartment

containing reticular fibers



RETICULAR CELLS



ReticularCell


ReticularCell



CHONDROGENIC CTs



!!!! HYALINE CARTILAGE

!!!! ELASTIC CARTILAGE

!!!! FIBROCARTILAGE


Chondroblasts/chondrocytes as resident cellsand extensive sulfated GAGs in ECM



HyalineCartilage

ElasticCartilage (stained to show elastic fibers)



Fibrocartilage stained with H&E



large collagen fibers

chondrocytes (usually in rows)between collagen fibers




Fibrocartilage stained with H&E

OSSEOUS CTs



!!!! WOVEN BONE

!!!! COMPACT BONE

!!!! CANCELLOUS or SPONGY BONE


Osteoblasts/osteocytes as resident cellsand mineralized ECM

Lamellar Bone



Woven Bone(matrix is less

organized)

(matrix is moreorganized)



Spongy Bone



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Biol 432 PP Connective Tissues