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Lab Exercise 6a-2
Connective TissueNervousMuscle
Classification of connective tissues
Connective Tissue
Connective tissue proper Fluid connective tissue Supportive connecting tissue
Connective tissuesConnective tissue proper
Loose connective tissue AreolarAdiposeReticular
Dense connective tissueDense regularDense irregularElastic tissue
Fluid CTBlood
Supporting CTsCartilageHyaline cartilageElastic cartilageFibrocartilage
• Bone
Areolar tissue
A loose CTP
Areolar
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Areolar: what to look for
FibroblastsCollagen fibersElastic fibersMast cells and macrophages
Found? Throughout body, under dermis, divides skin from underlying tissues
Fibroblasts
Resting fibroblasts typically have so little cytoplasm that the cells appear, by light microscopy, as "naked" nuclei
Fibroblast Adipose tissue
Another lose CTP (note nucleus)
Adipose: what to look for
Lots of cytoplasmSlim nuclei pushed off the side
Found? You know where
Reticular tissue
The third type of loose CTP
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Reticular tissue Reticular: what to look for
Reticular fibers (network)
Found? Internal framework in many sort organs (liver, spleen) supporting the parenchyma
Dense CTP
Dense regular – strength in one directionDense irregular – strength in all directionsElastic tissue - pliable
Dense regular
Dense regular: what to look for
Thick parallel bundles of collagenSmall fibroblasts in between bundles
Found? Tendons, ligaments, deep fascia.
Dense irregular
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More dense irregularDense irregular: what to look for
Mesh of collagen fibers (irregular looking)Interspersed fibroblasts
Found? Dermis of skin, periosteum, perichondrium
Elastic tissue Elastic tissue: what to look for
Elastic fibers (instead of collagen fibers) in large bundlesFibroblasts
Found? Between vertebrae, in blood vessel walls (underneath endothelium)
Fluid CT
Blood
Blood: what to look for
RBCsWhite blood cells (darker): monocytes, lymphocytes, granulocytesPlatelets
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Supportive CT
Cartilage – gelatinous, paddingHyaline cartilageElastic cartilageFibrocartilage
Hyaline cartilage
Glasslike because fibers not visible
More hyaline
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
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.
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Hyaline cart.: what to look for
Chondrocytes and lacunaeNo visible fibersWhere? Most joints, nasal septum
Elastic cartilage
Elastic Cartilage Elastic cart: what to look for
Many elastic fibers in matrixChondrocytes in lacunaeMay be stacked up
Fibrocartilage Fibrocartilage: what to look for
Irregular, wispy collagen fibersChondrocytes
Found? Intervertabral discs of spine, pads in knee joint
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Supportive CT: BoneDetail 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 forOsteon (whole circular structure)Concentric lamellae (of matrix)Central canal (at center of lamellae)OsteoblastsOsteocytes in lacunaeCanaliculi
Found? Bones!
Nervous tissue
Neuron smearLarge, pyramidal cell bodiesLong processes extending out
Nervous Tissue
Figure 4.10
3 Types of Muscle Tissue
Skeletal muscle:large body muscles responsible for movement
Cardiac muscle:found only in the heart
Smooth muscle:found in walls of hollow, contracting organs (blood vessels; urinary bladder; respiratory, digestive and reproductive tracts)
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Muscle Tissue: Skeletal
Long, cylindrical, multinucleate cells with obvious striationsFound in skeletal muscles that attach to bones or skin
Muscle Tissue: Skeletal
Figure 4.11a
Muscle Tissue: Cardiac
Branching, striated, uninucleate cells interlocking at intercalated discs
Muscle Tissue: Cardiac
Figure 4.11b
Muscle Tissue: Smooth
Sheets of spindle-shaped cells with central nuclei that have no striationsFound in the walls of hollow organs
Muscle Tissue: Smooth
Figure 4.11c
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ExercisesLook at all slidesDraw an example of each tissue on paper provided11 connective tissues:
6 CTP (3 loose, 3 dense)1 Fluid CT (blood) 4 Supportive CT (3 cartilage, 1 bone)
Neurons3 Muscle tissuesSkeletalStriatedSmooth
Turn in on Thurs 10/25
7 drawings from 6a-1 Epithelia15 Drawings from 6a-2 Connective+Review sheet for lab 6a