FOM 2.4.1 Flashcards
What the two types of fibers in connective tissue?
collagen, elastin
Describe how connective tissue can be broken down & classified.
Enter chart!
Name the three types of fibroblasts and where they’re found.
Chondroblast - cartilage Osteoblast - bone Odontoblast - teeth
What are the two resident cells in connective tissue?
Fibroblasts, adipocytes
Name the 4 collagen types and their defining characteristics.
I: fibers; skin, bone, ubiquitous II: network of fibrils; hyaline cartilage, elastic cartilage III: fibers, reticular fibers IV: networks (no fibers); basement membranes
What is released by fibroblasts?
either single alpha chain or procollagen (triple helix w/ loose ends)
What cleaves the loose end of procollagen to form collagen?
Peptidase
What are two effects of lysyl oxidase (LOX)?
Creating cross links -> making bridges and condensing chains
What are the four levels of organization in collagen?
alpha chains, collagen molecules, collagen fibrils, and collagen fibers
What is the collagen makeup of tendons?
Dense, regular type I collagen
What is the collagen makeup of skin?
Dense, irregular type I collagen
What are the three main substituents of ground substance?
glycosaminoglycans, glycoproteins, water
What type of collagen composes reticular fibers?
type III
What is/isn’t seen in H&E vs. Silver staining?
H&E: Type I shows, Type III doesn’t Silver: Type III shows, Type I doesn’t
Name the 4 components of elastic fibers.
Tropoelastin, Fibrillin I & II, & microfibril associated glycoprotein (MAGP)
What enzyme peforms the same action as LOX for elastin?
Trick question, LOX
Identify the three types of lamina in the basement membrane.
PIC rara, densa, reticularis
What is the lamina rara composed of?
laminin network
What is the basal lamina composed of?
laminin network & type IV collagen
What sequesters growth factors?
Proteoglycan GAG chains
In diabetics, what happens to the glomerular basement membrane (GBM)?
It progressively thickens
What type of collagen is present in hyaline & elastic cartilage?
Type II
What are the 4 S’s of connective tissue?
Support, Storage, Signaling, Sifting
Name what each of the arrows is coming from
Epithelial cells
Basement membrane
Endothelium lining capillary
Connective tissue with interstitial matrix
Fibroblast
Type 1 collagen is primarily found in?
Fibers; skin, bone, ubquitous
Type 2 cartilage is found as what and where?
Networks of fibrils; hyaline cartilage and elastic cartilage
Type 3 collages is found as what and where?
Fibers; reticular fibers
Type 4 collagen is found as what and where?
Networks (no fibers); basement membranes
What is this a picture of?
Dense irregular connective tissue
What types of collagen are the lamina densa and the lamina reticularis composed of respectively? What is also found throughout the basement membrane? What is the lamina lucidia primarily composed of?
The lamina densa is made up of type 4 collagen and the reticularis is made of type 3. Ground substance is found all throughout the basement membrane. The lamina lucidia is primarily composed of laminin.
What is a major difference between type 1 and type 4 collagen?
Type 1 collagen has the NC1 domain cleaved, while the type 4 uses it to bind with other type 4 molecules to for the meshwork.
How does laminin get bound to collagen?
Entactin binds the two networks together!!
What proteins provide the scaffolding for elastin?
Tropoelastin and fibrillin
What is the process of collagen syntesis?
- Translation of collagen alpha-chains (preprocollagen)
- Hydroxylation of specific proline and lysine residues
- glcosylation of pro-alpha-chains hydroxylysine residues and formation of procollagen (triple helix formation) – problems with triple helix formation leads to osteogenesis imperfecta
- Exocytosis of procollagen into extracellular space
- Cleavage of disulfide rich terminal regions of procollagen leads to insoluble tropocollagen
- Crosslinking - reinforcement of many staggered tropocollagen molecules making fibrils
