Lab 3 - Connective Tissue Flashcards

1
Q

5 common characteristics of CT

A

-there are no free surfaces, CT fills spaces with a mixture of cells and extracellular material

-CT underlies epithelia and surrounds muscle and nervous tissues, thus providing structural integrity and support to an organism

-CT also provides chemical support to other tissues; blood vessels and nerves run though CT to reach their destinations

-the ECM is the most abundant component of most CT and the properties of different types of CT are primarily determined by the composition of the ECM

-CT cells are often not connected to each other by cell-cell junctions

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2
Q

what are the two components of CT

A

cells and the ECM

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3
Q

what are the two types of cells in CT

A

-the fibroblast family makes and maintains this tissue. various cells will have different appearancs and names depending on location and activity

-bone marrow derived (immune system) cells are concerned with immune surveillance and defense. they travel through and reside in CT but dont contribute to its formation

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4
Q

what makes up the ECM (4)

A
  • collagen fibers = most abundant protein type in mammalian body, primarily collagen type 1 or 2. eosinophilic in H+E and provide tensile strength

-reticular fibers = are actually collagen type 3 thin fibers that stain poorly with H+E. they form supporting network in some organs

-elastin fibers = usually stain very pale with H+E unless in large sheets, but have light refractive properties. they provide stretch-recoil function to CT

-ground substance = composed of water, PG, GAG, soluble proteins and other water soluble molecules. can appear as empty spaces because they dont stain well with H+E, and the spaces are often enlarged by shrinkage during processing

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5
Q

what is the main cell type we see in dense CT

A

fibroblasts

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6
Q

why does loose CT tend to have more cells compared to dense

A

because there are numerous immune system cells moving throughout

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7
Q

what is a special type of loose fibrous CT

A

reticular tissue

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8
Q

why dont reticular fibers (collagen type 3) react well with eosin

A

they are very thin and highly glycosylated

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9
Q

how are adipose cells connected

A

-NOT by cell to cell junctions but rather they are held in densly packed arrays of reticular fibers/collagen type 3 fibers

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10
Q

what type of adipose tissue has chicken wire type appearance

A

unilocular/white adipose tissue

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11
Q

what is the territorial matrix

A

more dense staining around the lacunae - it contains more GAGs

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12
Q

what are some types of cartilage? what is the most common

A

-hyaline cartilage is most common
-fibrocartilage
-elastic cartilage

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13
Q

what is on both sides of the cartilage? how does it stain and why

A

perichondrium - stains more eosinophilic compared to the cartilage because there is more collagen present

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14
Q

what is another name for perforating canal

A

volkmans canal

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15
Q

when are you able to see the interstitial lamellae

A

in cross sections of ground bone only

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16
Q

what do mesenchymal cells differentiate into? and what does that do?

A

they differentiate into osteoblasts that synthesize bone ECM

17
Q

what are the 5 zones in endochondral ossification and what happens in each

A
  • the reserve zone = contains chondrocytes that are not currently dividing
  • zone of proliferation = consists of rapidly dividing chondrocytes. axis of cell division is oriented along the direction of cartilage growth so instead of small clumps of chondrocytes, we see long rows of chondrocytes in isogenic chains

-zone of hypertrophy = chondrocytes start to enlarge

  • zone of calcification = the cartilage ECM becomes mineralized and the chondrocytes eventuall die leaving empty lacunae space
  • zone of ossification =
18
Q

what do osteoclasts do?

A

degrade immature woven bone and some of the remaining mineralized cartilage to remodel it into mature lamellar bone

19
Q

osteoblasts vs osteocytes vs osteoclasts

A

osteoblasts = immature baby cells
osteocytes = mature cells that are trapped in the lacunae
osteoclasts = cells that degrade for remodeling

20
Q

at what point is it impossible for bone to grow any longer

A

when the epiphyseal plate cartilage stops proliferating, endochondral ossification converts the remaining portion of cartilage in the plate into bone and forming the bone marrow cavities becomes connected.

however it can still continue to thicken