Connective Tissue Flashcards

1
Q

CT vs. Epithelium

A

CT: widely spread, no polarity, vascularized (usually.. not cartilage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

general CT composition

A

cells + ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

CT cells

A

long-term resident or transient resident

principal cell produces ECM components, all other cells do something else NOT produce ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Principal long-term resident cell

A

produces ECM components (ground substance + fibers)

usually fibroblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ECM components

A
  • gelatinous ground substance + fibers/fibrils

- both parts produced by principal CT cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Ground Substance

A

rich in GAGs and proteoglycans (interact to form proteoglycan aggregates)
secrete multiadhesive glycoproteins (stabilize matrix and aid in cell-connective tissue interactions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

GAG

A

Glycosaminoglycan

-long chain, linear polysaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

GAGs in CT

A

in ground substance: keratan sulfate, heparan sulfate, condroitin sulfate, and hyaluronic acid (hyaluronan)

  • sulfate = negative (basophilic).. attracts sodium ions which attract water to the matrix
  • interact with proteins to form proteoglycans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

hyaluronic acid in ground substance

A
  • longer and more rigid than other GAGs

- increases the viscosity of ground substance (makes it thicker)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

proteoglycans

A
  • linear proteins with glycosaminoglycan (GAG) side chains

- look like a bottle brush

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

proteglycan aggregate

A

proteglycan + GAG (hyaluronic acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

mutiadhesive glycoproteins

A
  • secreted by principal CT
  • stabilize ECM and link EXM to the surface of cells
  • ex: fibronectin and laminin (attach epithelial cells to basal lamina)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

FIbrous component of CT

A
  • proteins secreted from principal CT cells

- proteins assemble into fibrils (TEM), which usually assemble inter fibers (LM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

3 major types of fibers in connective tissue

A
  1. collagen
  2. elastic
  3. reticular (type III collagen)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

constituency of CT

A

can be solid (bone) , watery (blood), or viscous (cartilage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

role of ground substance vs. fibers

A

fibers: tensile strength + resiliance

ground substance: diffusion of molecules + access of blood borne cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

fibroblasts (derived from? role in loose CT, function, in LM, in TEM)

A

derived from mesenchymal cells
PCT in loose CT
produce TYPE I COLLAGEN + ELASTIC FIBERS
in LM: elongated nucleaus, thin cytoplasm, and hard to tell (unless cell is making a lot of collagen)
in TEM: lots of rER (making proteins!), scalloped cell body, and thin processes extending from cell into collagen bundles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Macrophages (derived from? role in loose CT, function, in LM, in TEM)

A

derived from monocytes
-monocytes in blood, enter loose CT via diapedesis = macrophages
-function: resident phagocytic cells; phagocytosize bacteria or dying cells
in LM: larger nuclei than FB, and indented nuclear envelope, vesicles are apparent (foamy looking) when active
in TEM: lots of lysosomes, extending pseudo pods if active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

mast cells

A

promote inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

granules in mast cells and their respective function

A
heparin (anticoagulant); 
histamine (promotes inflammation);
eosinophil chemotactic factor
tryptase (mast cell marker)
NO leukotrienes (produced from PM after the release of granules)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

uriticaria

A

hives;

produces from skin mast cell activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

explain inflammation response via mast cell (starting from antibody production) (DEGRANULATION OF MAST CELLS)

A
  1. antibody produced by plasma cell and released
  2. IgE specific receptor on extracellular mast cell bind the antibody to the mast cell
  3. antibodies bind to antigen (when present)
  4. ca 2+ channels open (calcium influx)
  5. granules pour out supstances: heparin (anticoagulant), histamine (promotes inflammation), eosinophilic chemotactic factor
  6. production of leukotrienes from PM (promotes inflammation)
    “promote inflammation” = calls for leukocytes from blood vessel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

leukocytes

A

promote immune response to antigens, parasites, or bacteria (that pass through epithelium)
-include granulocytes and agrangulocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

cells in CT

A
  1. fibroblasts (produce collagen type I + elastic fibers)
  2. Macrophage (phagocytsize bacteria + old cells)
  3. Plasma cells (make antibodies)
  4. Mast cells (promote inflammation)
  5. adipose (energy storage, convert hormones to estrogen, weight control)
  6. leukocytes (promote immune response..WBC)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Loose CT ECM

A

produced from fibroblasts (PCT)

contain type I collagen, elastic fibers + viscous ground substance (sulfated and non-sulfated glycoasminoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

type I collagen

A
  • most abundant type of collagen in humans
  • most of loose and dense CT
  • high tensile strength, but very flexible (links on a chain)
  • best visualized with trichrome stain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how is type I collagen produced?

A
  • from fibroblasts
    1. FB secrete procollagen via constitutive exocytosis into ECM;
    2. peptidase cleaves terminal end of procollagen = tropocollagen
    3. tropocollagen proteins self assemble into collagen fibrils
    4. fibrils assemble into eosinophilic fibers that are held together with proteoglycans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

type IV collagen

A
  • component of basal (external) lamina
  • secreted by epithelial cells, adipocytes, schwann cells, muscle cells
  • (also the anchoring protein in hemidesmosome)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Elastic fibers content/compostion

A

-made of elastic fiber, elastin (desmosine + isodesmosine), fibrillin, other glycoproteins
LITTLE HYDROXYPROLINE; NO HYDROXYLYSINE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

function of elastin

A

stretchiness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

function of fibrillin

A

organizing and structural protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

desmosine and isodesmosine

A

bind adjacent elastin molecule together to allow them to stretch and recoil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

elastic fiber stain

A

orecein, resorcin fuchsin, aldehyde fuchsin, verhoeffs stain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Dense CT (Regular): location, structure

A
  • in tendons/ligaments, type I collagen fibers are oriented linearly in direction to best resist stress
  • poorly vascularized
  • FB nucleus widely spread (compared to smooth muscle and peripheral nerve)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Dense CT (Irregular): location/structure

A
  • in dermis of skin and capsule of other organs
  • type I collagen is arranged into sheets and stacked. within each sheet the fibers are all lineraly aligned in one direction, but since the layers are stacked, it appears like they are going in all different directions (FB randomly w/in the collagen)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

vit C and collagen?

A

vitamin C is a cofactor in the synthesis of type I collagen; deprivation of vit c greatly reduces collagen synthesis resulting in SCURVY (especially seen in the periodontal ligament anchoring teeth in their bone sockets.. loose teeth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Loose CT vs. Dense CT

A

Loose: more cells less collagen
Dense: more collagen less cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

reticular fiber formation

A

via reticular cells: same as collagen I production (via FB):
-reticular cell secretes procollagen, cleaved to tropocollagen, assemble to collagen III fibrils, fibrils arrange into a mesh-bag network

39
Q

reticular fiber stain

A

PAS (carbohydrates), silver

40
Q

Ehlers Danlos Type IV Syndrome

A

insufficient synthesis of type III collagen… aorta and intestines have large amounts of type III.. thus they are very prone to rupture

41
Q

Marfan’s syndrome

A
  • caused by mutations in the gene for microfibrilar component of elastic Ct
  • affects large vessels
  • elastic wall of aorta is deficient and leads to rupture
42
Q

fibers affiliated with adipocytes

A

reticular (collagen III) network

43
Q

Mesenchyme

A
  • loose, primitive CT found in embryo

- allows passage of cells and fluid within the organ

44
Q

whartons jelly

A

found in umbilical cord
ground substance has lots of hyaluronic acid and sulfated GAGs that draws in water… makes the ground substance a good compression protection.. which prevents the umbilical cord from kinking
TYPE I +III collagen

45
Q

Brown Fat

A

has multiocular fat cells (lots of lipid inclusions and lots of mitochondria… make it look brown). this fat is good for converting lipid into thermal energy type III collagen

46
Q

cartilage (general)

A
  • flexible CT that resists compression and provides an organizing framework for other cells
  • avascular
  • aneaural
47
Q

3 types of cartilage

A
  1. hyaline
  2. elastic
  3. fibrocartilage
48
Q

what type of cartilage is surrounded by perichondrium? what is perichondrium

A
  • hyaline + elastic cartilage
  • dense irregular CT (fibroblast) = outer layer
  • chondrogenic layer of chondrocytes (produces chondrocytes) = inner layer
49
Q

aggrecan

A

a proteoglycan that contains high concentrations of sulfated GAGs (keratan sulfate + chondroitin sulfate)

50
Q

whats the advantage of sulfated gags?

A

bring in water (negative sulfate attracts sodium, which brings water with it).
this results in a ground substance that can resist compression
and in cartilage: allows free diffusion of material to/from blood vessels outside the cartilage

51
Q

why is the matrix of hyaline cartilage basophilic?

A

lots of sulfated GAGs

52
Q

Lacuna

A

space that contains a chondrocyte inside (visible in H/E after the cell shrinks)
-territorial matrix/interterritorial matrix

53
Q

territorial matrix

A

borders the lacuna; appears darker because the GAGs (matrix material) is concentrated there… very basophilic

54
Q

interterritorial matrix

A

between the groups of matrix; stains lighter (ie: if there are two chondrocytes/lacunae next to each other, then two dark circle around the chondrocyte = territorial matrix, and the little space between them is the interterritorial matrix)

55
Q

Cartilage growth

A

2 ways:

  1. appositional
  2. interstitial
56
Q

appositional cartilage growth

A
  • growth at the edges
  • chondroblasts in inner chondrogenic layer of perichondrium divide and add to cartilage along the outside
  • “chondrogenic” cells of the perichondrium (i.e., the cells in the overlying CT that have the potential to become chondrocytes) gear up, begin active synthesis, and start creating new cartilage at the boundaries of the structure. Eventually these new chondrocytes will become trapped in lacunae and become integrated as part of the main mass of cartilage. At that point, if they’re still active in synthesis, they’ll be participating in interstitial growth.
57
Q

interstitial cartilage growth

A
  • growth from the inside
  • mitosis of chondrocytes in lacunae produce isogenous groups of cells (clones) within the cartilage matrix
  • result of chondrocytes in their lacunae actively synthesizing matrix material. This causes the total volume of the cartilaginous structure to increase
58
Q

Fibrocartilage

A

combo of dense regular CT + chondrocytes (no perichondrium)

  • function as a strong anchor for dense CT
  • in public symphosis, intervertebral discs, meniscus of knee etc.
59
Q

cartilage repair

A

damaged cartilage is largely incapable of repair.. avascular! few chondrocytes are added following damage (most repair is done by producing more dense CT)

60
Q

hyaline cartilage can ossify as a part of normal aging

A

ie: in tracheal cartilage

61
Q

osteoarthritis

A
  • erosion of the hyaline cartilage lining the articular surfaces of bones
  • loss of aneural cartilage allows grinding of bony surfaces (highly innervated .. produce intense pain
62
Q

chondroma vs. chondrosarcoma

A
chondroma = benign tumor formed by chondrocytes
chondrosarcoma = malignant
63
Q

PCT in Loose CT

A

fibroblast

64
Q

fibers in Loose CT

A

type I collagen + elastic fibers

65
Q

ground substance in Loose CT

A

sulfated and nonsulfated GAGs

66
Q

PCT in dense CT

A

fibroblasts

67
Q

fibers in dense CT

A

type I collagen mainly (some elastic)
in regular: all run in the same direction
in irregular: run obliquely

68
Q

ground substance in dense CT

A

minimal - GAGs

69
Q

PCT in reticular CT

A

reticular cells (lymphatics), schwann cells, adipocytes, muscle cells

70
Q

fibers in reticular CT

A

type III collagen

71
Q

ground substance in reticular CT

A

minimal- GAGs

72
Q

PCT in elastic CT

A

fibroblasts, chondrocytes, smooth muscle

73
Q

fibers in elastic CT

A

elastic fibers mainly

  • elastin = fiber component
  • fibrilin = microfibril component
74
Q

ground substance in elastic CT

A

minimal- GAGs

75
Q

PCT in adipose

A

adipocytes

76
Q

fibers in adipose

A

reticular fibers (type III collagen)

77
Q

ground substance in adipose

A

minimal - GAGs

78
Q

PCT in mesenchyme CT

A

mesenchymal cells

79
Q

fibers in mesenchyme

A

type III collagen

80
Q

ground substance in mesenchyme

A

abundant: thin, gelatinous

81
Q

PCT in Wharton’s Jelly

A

mesenchymal cells

82
Q

fibers in Wharton’s Jelly

A

type III collagen fibers (reticular) + type I collagen

83
Q

ground substance in Wharton’s Jelly

A

Jelly- like

lots of hyaluronic acid + sulfated GAGs cause an influx of water.. its good for compression

84
Q

PCT of brown adipose tissue

A

multilocular adipocytes rich in mitochondria

85
Q

fibers of brown adipose tissue

A

type III collagen fibers (reticular fibers)

86
Q

ground substance of brown adipose tissue

A

minimal - GAGs

87
Q

hyaline cartilage PCT

A

chondrocyte

88
Q

fibers in hyaline cartilage

A

type II collage FIBRILS

89
Q

ground substance in hyaline cartilage

A

aggrecan (high concentration of sulfated GAGs (keratan sulfate + chondroitin sulfate))

90
Q

PCT in elastic cartilage

A

chondrocyte

91
Q

fibers in elastic cartilage

A

type II collage FIBRILS

elastic FIBERS

92
Q

ground substance in elastic cartilage

A

aggrecan

93
Q

PCT in fibrocartilage

A

chondrocyte + fibroblast

94
Q

fibers in fibrocartilage

A

type II collagen FIBRILS

type I collagen FIBERS