Connective TIssues Charecteristics Flashcards
1
Q
Connective Tissue Charecteristics
A
- Connective tissue is what is left over after everything else(epithelia,muscle, and nervous tissue) is removed
- It is found in every organ system except the CNS
- Unlike epithelial tissues, connective tissue has relatively few cells
- Major charecteristic of connective tissue is an abundnat matrix
- connective tissue matrix contains varying amounts of protein fibers
- Connective tissue is typically classified on the basis of tye type of matrix,fiber denisty, and fiber organization
2
Q
Connective tissue Functions
A
- Connective tissue physically supports other tissues
- Connective tissue binds other tissues together
- Connective tissue provids strucutural framework and oppose gravity
- Connective tissue helps to create body counters
- Connective tissue house specialized tissues(i.e.):
- Blood forming tissue(hematopoietic)
- Lymphoid tissue
3
Q
Connective TIssue Classification
A
- Embryonic connecitieve tissue
- adult connective tissue:
- Loose
- Both collagen and elastic fibers are present and arranged in a very loose,random fashion
- Dense
- collagen fibers predominate
- Dense regular
- Dense irregular
- collagen fibers predominate
- Reticular
- reticular fibers predominate
- Elastic
- Elastic fibers predominate
- Loose
- Special
4
Q
Embryonic Connective Tissue
A
- Found in umbilical cord and in the pulp of developing teeth
- Referred to as “Wharton’s” jelly in umbilical cord
- Composed of some collagen and elastic fibers but mostly an abudnacne of extracellular matrix
5
Q
Adult connective tissue loose
A
- High ratio of fibroblasts to fibrous components
- Type I collage nfibers adn elastic fibers
- Usually found beneath epithelial tissues of most organs,including the tunica adventita of blood vessels
- Contains fibroblasts , mast cells,macrophages,and capillaries
6
Q
Adult connective tissue , Dense regular
A
- High ratio of fibrous components to fibroblasts
- thicker bundles of collagen than in loose connective tissue
- Dense regular connective tissue is charecterized by highly ordered bundles of collagen separated by single rows of fibroblasts
- found in tendons and ligaments
7
Q
Adult Connective Tissue Dense irregular
A
- High ratio of ibrous componets to fibroblasts
- Thicker bundles of collagen than in loose CT
- Dense irregular connective tissue has no specific orientation of collagen bundles
- Found in fascia, submucosa of GI tract, and in dermis of integument
- No parallel organization but still densely packed
8
Q
Reticular
A
- A type of dense irregular connective tissue with a predominance of reticular fibers
- Associated primarily with lympathic tissue
9
Q
Elastic
A
- A type of dense irregular connective tissue with an abudnane of elastic fibers which form discontinuous lamellae
- Associated with walls of blood vessels:
- Note that elastic fibers in walls of blood vessels are produced by smooth muscle cells rather than fibroblasts
10
Q
A
Tendon and muscle
11
Q
Special types of connective tissue
A
- Adipose
- carilage
- bone
- Hematopoietic(blood forming tissue)
- Special becasue the protein fibers are not conspicous
- wouldn’t recognize it or know that it’s connective tissue
- Embryonic morphology also plays a part in classification
12
Q
Adipocytes
A
- Derived from undifferentiated mesenchymal cells and are distinguished by their unique apperance
- Most are about 150 micrometers in diameter
- Types:
- White fat is distributed throughout the body:
- unilocular-a single large fat inclusion, resulting from coalescing multiple lipid droplets , pushes the nucleus to an eccentric position
- Brown fat cells contain numerous small lipid droplets:
- Multiocular
- Slighly more cytoplasm
- Abundnat mitochondria , which give them their brown coloration
- White fat is distributed throughout the body:
13
Q
A
Adipose tissue
14
Q
connective Tissue Matrix
A
- Connective tissue proper consists of cells scattered in a relatively homogeneous matrix
- most common cells are fibrocytes and fibroblasts
- The matrix consists of protein fibers and ground substance
- Most abundnat fibers are collagen fibers
- other fiber tpes include reticular fibers and elastic fibers
- ground substance is mostly composed of glycosaminoglycans and glycoproteins
15
Q
Collagen Fiber types
A
- Type1: General CT and bone
- Function:tensile strength
- Type2: hyaline and elastic cartilage
- Function:tensile strength
- Type3: Parenchyma of organs adn walls of blood vessels
- Function:reticular framework
- type 4:Basment membranes
- Function:meshwork,scaffolding
16
Q
Collagen fiber synthesis
A
Type I collage is synthesized as a prepropeptide
- Signal(pre-)sequence is cleave after translocation of the polypeptide into the endoplasmi reticulum(ER) lumen of the fibroblast
- After the singal sequence is cleaved , the propeptide(procollagen) molecule is secreted by the firoblast into the extracellular matrix
- Procolagen molecule has terminal non-helical ends that prevent polymerization
- These non-helical ends are cleaved by petidases in order to allow polymerization to occur
- After the terminal ends are cleaved , the molecuel is referred to as tropocollagen
- Tropocollagen monomers spontaneously assemble into staggered arrays to fomr collage fibers with characteristic 64nm banded pattern
- assembled polymer is collagen
17
Q
Elastic Fiber synthesis
A
- Elastin is also synthesized as a prepropeptide
- The prepropepide is secreted as a propeptide
- Propeptide is converted to tropelastin by extracellular enzymes , also secreted by the fibroblast
- Tropoelastin monomers are assembled into amorphous fibers or sheets with the aid of several types of fibrillins
23
Q
Proteoglycans are extracellular protein complexes of glycosaminoglycans
A
- An axial hyaluronan molecule
- core proteins attached to the hyaluronan molecule by a linker protein
- Glycosaminoglycnas attached to a core protein
- Several chains of glycosaminoglycans bound to the core protein form a prtoeglycan
