Connective Tissue Flashcards
what is the role of connective tissue
Connective tissue provides structural metabolic and defensive support within other tissues and organs, thereofre they are sometimes called supporting tissue
name the different types of connective tissue
- Fibrocollagenous tissues
- Adipose tissue
- Cartilage
- Bone
- Blood
what is the characteristic of connective tissue
- Few cells compared to epithelia and other tissues
- Large amounts of extracellular matrix, usually made by its intrinsic cells
where are connective tissue cells derived from
mesodorm
- Some stem cells remain in the adult these are called mesenchymal cells
name the language of connective tissue
- Blast means immature
- Cyte means mature
- Fibroblast is the excpetion
what makes up the extracellular matrix
- Ground substance – in most types, this is a smei-lfuid gel though which metbaolites can diffuse through
- Structual glycoproteins
- Fibres – colllagen fibres for strength and support and elastic fibres for stretch
describe what the ground substance does
- Water to gel like
- Gives each connective tissue distinctive properites
what makes up the ground substance
- Made of GAGs and proteoglycans (bind via a linker to hyalurinc acid to form either larger complexes)
- Fluid components with dissolved substances including nutrients, electroyltes, gases and hormones
- Structural glycoproteins – molecules with different functions such as aiding fibre assembly, promoting cell adhesion or calcium deposition
describe GAGs
- Negatively charged
- Open conformations
- Retain water and postivie ions
- Make up extracellular fluid
- Forms a hydrated gel that allows selective passage of molecules
what is the role of structural glycoproteins
- Functional molecules
- Role in linking, organising, catalysing processes, folding of proteins and carriers of molecules
what are the different types of collagen
- Type 1 : thick bundles that are very strong
- Type II: thin, interwoven fibres that are only in cartilage
- Type III: delicate branching reticulin
- Type IV: forms meshwork – important in the basement membrane
what does collagen secrete
- precursor tropocollagen secreted
what are fibre precursors secreted by
connective tissue cells, fibres polymersie outside of the cell
describe elastic fibres
- Stretch and resiliency
- Tropoelastin secreted
- Elastin forms fibrils with fibrillin
- Fibres can be organised into sheets
- Higher amounts found in arteries, skin, lung, elastic and cartilage
how is fibrocollagenous tissue classed according too
- Number or amount of collagen fibres
- Organisation of collagen fibres
- Type of collagen fibres
describe the
- cell that makes the fibrocollagenous tissue
- the role it plays
- the types of the tissue
Cell: fibrobaslt – responsible for making the cells in the extracellular matrix in fibrocolllagenous tissues
Role: structural and supportive
Types; you can have loose, desne, and reticular (type of loose collagen III)
describe loose areolar connective tissue
- cell
- role
- example
- location
- Cells: Fibroblasts – also stem cells, adipocytes, lymphocytes, resident macrophages, mast cells
- relatively few collagen type I fibres bundles that are oriented in different directions, there are some type III fibres that are present
- Role – physical, metabolic and defensive support, plays role in inflammation, holds and conveys tissue fluid
- Example – lamina propria
- Location – distributed under the epithelial of the body, packages organs, surrounds capilaires
whats denser the submucosa or the lamina propria
although submucosa is loose CT the density of collagen fibres is higher than the lamina propria of the mucosa above it, the submucosa has a more supportive function and is more robust
describe dense connective tissue amount organisation type cell role examples
- Amount – many fibres, little ground substance
- Organisaiton – radom – desne irregular, structured – dense regular
- Type – type I collagen, mainly elastic fibres, reticulin
- Cells: fibroblasts primarly
- Role: mechanical support and tensile strength
- Examples: irregular – dermis (many directions), capsules, regular- tendon and ligament (one direction)
describe dense irregular
irregularly arranged collagen, some elastic fibers, major cell type is fibroblast
describe the function of dense irregular
can withstand tension exerted in many dreictions and provides structural strength