Lab Exercise #8
Connective Tissue
Characteristics of
Connective Tissues
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Specialized cells
Solid extracellular protein fibers
Fluid extracellular ground substance
These latter two extracellular features are
called Matrix
The Matrix
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The extracellular components of connective
tissues (fibers and ground substance):
majority of volume
 determines specialized function
e.g. connective tissue proper  syrupy liquid
cartilage  gel-like matrix
blood  fluid matrix
bone  crystalline solid
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Classification of connective
tissues
Today’s Lab
Lab #8. Connective Tissue
Connective Tissue
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Connective tissue proper
Fluid connective tissue
Supportive connecting tissue
Connective tissues
Connective tissue proper
 Loose connective tissue
 Areolar
 Adipose
 Reticular
 Dense connective tissue
 Dense regular
 Dense irregular
 Elastic tissue
Fluid CT
Blood
Supporting CTs
Cartilage
Hyaline cartilage
Elastic cartilage
Fibrocartilage
•
Bone
Areolar tissue
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A loose CTP
Areolar
Areolar: what to look for
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Fibroblasts
Collagen fibers
Elastic fibers
Mast cells and macrophages
Found? Throughout body, under dermis,
divides skin from underlying tissues
Fibroblasts
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Resting fibroblasts typically have so little
cytoplasm that the cells appear, by light
microscopy, as "naked" nuclei
Fibroblast
Adipose tissue
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Another lose CTP (note nucleus)
Adipose: what to look for
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Lots of cytoplasm
Slim nuclei pushed off the side
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Found? You know where
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Reticular tissue
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The third type of loose CTP
Reticular tissue
Reticular: what to look for
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Reticular fibers (network)
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Found? Internal framework in many sort
organs (liver, spleen) supporting the
parenchyma
Dense CTP
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Dense regular – strength in one direction
Dense irregular – strength in all directions
Elastic tissue - pliable
Dense regular
Dense regular: what to look for
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Thick parallel bundles of collagen
Small fibroblasts in between bundles
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Found? Tendons, ligaments, deep fascia.
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Dense irregular
More dense irregular
Dense irregular: what to look
for
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Mesh of collagen fibers (irregular looking)
Interspersed fibroblasts
Found? Dermis of skin, periosteum,
perichondrium
Elastic tissue
Elastic tissue: what to look for
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Elastic fibers (instead of collagen fibers) in
large bundles
Fibroblasts
Found? Between vertebrae, in blood vessel
walls (underneath endothelium)
Fluid CT
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Blood
Blood: what to look for
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RBCs
White blood cells (darker): monocytes,
lymphocytes, granulocytes
Platelets
Supportive CT
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Cartilage – gelatinous, padding
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Hyaline cartilage
Elastic cartilage
Fibrocartilage
Hyaline cartilage
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Glasslike because fibers not visible
More hyaline
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There are collagenous and elastic fibers lying
in the cartilage matrix but they are invisible
because their “refractive index” is the same
as that of the matrix (like cornea)
More hyaline
Hyaline cartilage
Hyaline
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Hyaline cartilage (lavender matrix), with
perichondrium (pink) outside it. The latter is a
dense regular collagenous CT. Cartilage cells
= chondrocytes, and they are lying in the
lacunae.
Hyaline cart.: what to look for
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Perichondrium
Chondroblasts (make the matrix fibers and
ground)
Chondrocytes and lacunae
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Where? Most joints, nasal septum
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Elastic cartilage
Elastic cart: what to look for
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Many elastic fibers in matrix
Perichondrium
Chondroblasts
Chondrocytes in lacunae
Fibrocartilage
Fibrocartilage: what to look for
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Irregular, wispy collagen fibers
Chondrocytes
Found? Intervertabral discs of spine, pads in
knee joint
Supportive CT: Bone
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Detail of lacuna, showing radiating canaliculi. Tissue fluid from
the capillaries and connective tissue of the Haversian canal can
seep through these spaces and channels, bringing nutrients to
the stellate osteocytes residing there.
Bone: what to look for
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Osteon (whole circular structure)
Concentric lamellae (of matrix)
Central canal (at center of lamellae)
Osteoblasts
Osteocytes in lacunae
Canaliculi
Found? Bones!
Exercises
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Look at all slides
Draw an example of each tissue (11) on
paper provided
6 CTP (3 loose, 3 dense)
 1 Fluid CT (blood)
 4 Supportive CT (3 cartilage, 1 bone)
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Due next Tuesday (6/3)
Turn in next Tuesday
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Drawings of 11 tissues
Lab Report 8 (A,B,E)