Chapter 6 - Connective Tissue Flashcards
What is ECM made out of? (3)
- Fibers
- Amorphous Ground Substance
- Extracellular Fluid
Types of embryonic CT? (2)
- Mesenchyme
- Mucos CT
When does mesenchyme tissue develope?
Established early in embryo, only found in the mesoderm
What does mesenchyme tissue give rise to?
Various CT of the body
What does mesenchyme CT look like?
Small
Uniform
Spindle-shaped cells
3D cellular network
Viscous ground substance with lots of reticular fibers
What type of collogen is reticular fibers? Where are they found? What are they indicitive or?
Collagen III, very thin
Indiitive of immaturity (new wound) or of a low force area (ex protected in embyonic fluid)
What are the characteristics of mucous CT?
Loose network of collagen fibers
More fibers than mesenchyme
Type I collagen replaces reticular fibers of mesenchyme
Widley-spaced mesenchymal cells = appear fibroblast-like
What is worton’s jelly? Where is it found?
A specialized felatin-like ECM
In Mucous CT
Where is mucous CT found?
In the umbilical cord
What are the types of CT proper?
- Loose (areolar)
- Dense (could be irregular or regular)
What are the characteristics of loose CT?
Thin, sparse like collagen fibers
Lots of ground substance
What occurs at sites with loose CT?
Inflammatory and immune reactions
Where is loose CT located? (3)
- Under the epithelial layer
- Glands
- Small Blood Vessels
What function does fibrobast serve?
Fibroblasts makes all the fibers and ground substance in all CT proper
Why do immune responses happen in loose CT?
Loose CT is near blood vessels and the epithelium which is a survalence point for the immune system
What are the characteristics of dense CT?
Bundled, web-like collagen
Sparse cells
What does the irregular organization of collagen I in irregular dense CT promote?
Increasing the irregularities increases the strength of the CT and decreases tearing
What is the only cell type in dense CT?
Fiberblasts
Where is irregular dense CT found? (2)
- Submucosa
- Reticular (deep layer)
What are the characteristics of regular dense CT?
Ordered in dense collagen bundles
Minimmal ground substance
Where is dense regular CT found? What is it doing at each location? (3)
- Tendons - bind muscle to bone
- Ligaments - bind bone to bone
- Aponeuroses - anchor muscles to broad flattened tendons (ex on palm of hand or footpad)
Are there blood vessels in Dense CT?
No
What is the peratindinum? Where is is located? What is its purpose?
Surrounds fibers in DCT and is a collection of blood vessels, nerves, and LCT (?)
What two componets make DCT elastic?
Collagen I + elastic fibers
What are the 3 components of ECM?
- Fibers
- Ground Substance
- Tissue Fluid
What are the 2 main components of CT?
- Cells
- ECM
What are the two types of fibers found in CT?
- Collagen
- Elastic
What is the most abundent structural component of CT?
Collagen
What are the characteristics of collagen?
Felxible with high tensile strength
Ineslastic
What is a fribil?
The largest collogen strucute made of overlaopping collagen molecules
A collagen molecule is composed of 3 _ chains with every third amino acid being ______
Composed of 3 alpha chains
Third amino acid being glycine
List the ordered structure of collogen from smallest to largest
Amino acids
Triple amino chains
Collagen molecule
Stagered confirmation
Fibril
alpha chains vary in ____ and ______
size and composition
Fibrillar collagen from what kind of bundels?
Tight bundles
Type I, II, III, IV
Basement membrane forming collagen
Make net like structure
type IV
What are FACITS?
Fibular Associated Collagen with Interuppted Triple helices
No packing
Kink acts as connection
What are the 3 main steps of collagen synthesis? (2)
- Transcription and Translation
- Post Translation Modifications
- Assembly into Fibers
What post-translation modifications occur in collagen synthesis?
- Add hydroxyl gorups to Lys and Pro to make hydrogen bonds
- Gycolylation at N and C terminus and hydroxy-lysines
- Cleavage of globular ends by proteases
What happens if you don’t get the hydroxylation of pro and lys during collagen synthesis?
You decrease the amount of type I collagen which leads to weak bones, wounds that don’t heal, and teeth that bleed and fall out
What happens inf you don’t get the glycosylation of specific hydroxy-lys residues?
No covalent bonds in fibers, the collagen won’t hold its shpae which means you don’t get any fibrils
What types of collagen form the fibrillar core of type I collagen fibrils? What type is deposited on the fibrillar core?
Type V (dictate how think fibril will become - is a FACIT)
and XI
Type I deposited on fibrillar core
What type of collagen does type II collagen fibril associate with? What is its function?
Type IX
Type IX connect fiber to ECM components