HE8 & 9 Connective tissues Flashcards
(40 cards)
Important functions of CT?
Structure (bones, cartilage, ligaments), Movement (ligaments). Support glands/organs. Store fat.
- Attracts water
- Exchanges blood/lymph, fluid.
- initial site of response to injury/host defense
Composition of CONNECTIVE TISSUES?
Cells separated throughout an Extracellular matrix ECM.
Composition of GROUND SUBSTANCE?
- Glycosaminoglycans (GAGS)
- Proteoglycans (PG’s)- > protein core w/ GAG’s
- Multiadhesive glycoproteins (MGP’s)
Composition of GAG’s
- repeating units of DISACCHARIDES (not mono or tri)!
- NEGATIVELY CHARGED
and most are SULFATED (hyaluronin not sulfated)
Primary function of glycosaminoglycans and proteoglycans? Function in BM?
important for movement of cells/materials & est. concentration gradient.
Basement membrane= CHARGED BASED FILTRATION BARRIER
Proteoglycan agregates structure and function
Glycosaminoglycans bound to a core protein forms a hydration unit of PROTEOGLYCAN.
Proteoglycans are linked by “linker proteins” to HALURONIN protein core
Gives ECM gel-like state, resisting compression to act like “SHOCK ABSORBERS”
GAG’s, PG’s, PG agregates at LM
GAG’s/PG’s high negative charge stain w/ basophilic BLUE basic dyes
HE STAIN= BLUE/PURPLE
PAS= MAGENTA/PINK
Multiadhesive glycoprotein (MGP) 5 Structures/ 4 functions.
Remember picture of MGP’s parallel under plasma membrane bound to green INTEGRINS which go through plasma membrane and attached to actin.
- Fibronectin
- Laminin
- Tenascin
- Osteopontin
- Enactin/Nidogen
- ECM assembly/structure
- Adhesion (fibroblast to ECM)
- Mechanosensation (FOCAL ADHESION)
- Regulate cell migration
Fibronectin, Laminin, or Osteopontin are examples of what?
Multiadhesive glycoproteins
Elastic fiber distribution. STAIN? Structure?
- Dermis-skin
- Heart valves
- Walls of large arteries (AORTA)
- Lungs (alveolar walls)
Ocrein used to distinguish between collagen and elastic fibers.
ELASTIN core with FIBRIN microfibrils
What 4 cells make COLLAGEN?
Where does Fibril formation occur?
What 3 categories? and what type Collagen in each category?
- Fibroblasts
- Epithelial cells
- Smooth muscle cells
- Schwann cells (PNS)
MADE OUTSIDE THE CELL!
- Tropocollagen–>Fibril
- Fibrillar (I,II,III)
- Network forming (IV)
- Anchoring (VII)
AT TEM what periodicity seen in Collagen?
68nm
68nm periodicity relates to what kind of cell?
Collagen FIBRILS (type 1,2,3). as a result of the orderly staggered assembly of tropocollagen into fibrils (overlap and holes).
Which type of molecule forms Fibrils, Fibers, and Bundles? Where found?
WHAT STAIN>
TYPE 1 COLLAGEN.
- sclera
- dentin
- orgain/joint capsules
- scar tissue
(Dermis, hypodermis, fascia, bones, ligaments, joints, tendons)
HE=pink bundles
TRICHROME-blue green
_______ found in cartilage and vitreous humor and stain______ whith _______stain. What happens if there is alot of PG’s present with it?
Type 2 Collagen
(restrains PG aggregates from expanding)
stains light pink with HE stain. if high PG’s blue masks over light pink type 2 collagen
LM looks like smooth fiberglass finish (blue, light pink) with large eye looking bubbles. TEM looks like unfinished rough fiberglass like on back side of a tub/shower
Type 2 collagen fibrils
____is first type of collagen in embryo and during adult injury repair and is replaced with ______. When heavily _____ the fibers are referred to as _______. They are often stained ______ with _____.
TYPE 3 COLLAGEN, TYPE 1 COLLAGEN, GLYCOSYLATED, RETICULAR FIBERS, BLACK, SILVER STAIN.
What type of collagen fibers form a delicate lattice that supports organs that :
- filter blood/lymph (liver,spleen,lymph),
- rich vasculature (endocrine organs),
- proliferating cells (bone marrow)
Reticular fibers of Type 3 collagen.
REINFORCE/SUPPORT SMALL BLOOD VESSEL WALLS
found supporting: Adipocytes Smooth muscle fibers peripheral nerve fibers -walls of blood/lymph vessels
What connective tissue supports/anchors epithelium to BL and is part of the filtration barrier?
Structure? Location? Function?
TYPE IV COLLAGEN- Basal Lamina- FILTRATION
- no fibrils or periodicity
- flat sheets of type IV MONOMERS
Attaches Epithelium to BL
What connective tissue anchors BL to RL?
Type VII Collagen- Anchoring FIBRILS
RL ADHESION!
Problems in what type of collagen cause HEMATURIA, BLISTERS, BRUISING, TENDON RUPTURE, OCULAR SHAPE CHANGE?
Type IV— BL FILTRATION- blood in urine
Type VII—RL ADHESION- blisters
Type III—- Supports small blood vessels- bruising
Type I—— bundles DiRCT- tendon injury
Type II—– Restrains PG’s in vitreous - eye deformities
PRIMARY FIBER DEFECTS & PATHOLOGY:
Type 1,2,3,4,7
I. Osteogenesis imperfecta II. Achondrogenesis II III. Ehlers-Danlos IV IV. Alport's syndrome VII. Kindler's Syndrome
Alport's syndrome- Kindlers syndrome- Ehlers-Danlos IV Achondrogenesis II Osteogenesis imperfecta
I. Osteogenesis imperfecta II. Achondrogenesis II III. Ehlers-Danlos IV IV. Alport's syndrome VII. Kindler's Syndrome
Where is CT derived from ? Where is that derived from?
Mesenchymal cells– from mesoderm and Neural Crest
Adults have mesenchymal-like cells in CT
