FoM:L4 - Connective Tissue Flashcards
What are the functions of connective tissue?
- support and shape
- interface for diffusion
- insulation and energy storage
- transport
- protection and defence
What does CT almost always develop from?
mesoderm
What are the 2 types of CT proper?
loose and dense
depends on ratio of cells to ECM
What are the 4 types of specialised connective tissue?
- adipose
- cartilage
- bone
- blood
What is the ECM made of?
fibres and ground substance
What is collagen?
- protein fibre
- provides strength
- found in skin, tendons, ligaments and bone
What is reticulin?
- collagen type III
- fine network of branching fibres
- endocrine, lymphatic and haematopoietic organs
What is elastin?
- discontinuous sheets
- stretching and recoiling
What is ground substance?
- GAGs and glycoproteins
- extracellular fluid binds to these
- volume and compression resistance
- passage of molecules through tissues
What are resident cells?
-blasts: young, synthesise and secrete ECM
-cytes: mature cells that maintain tissue
main types:
fibroblasts - abundant, more active
fibrocytes - scantly, less active, can revert to fibroblasts
What are wandering cells?
cells that move from blood to CT in response to stimuli (e.g. lymphocytes, plasma, neutrophils)
What is loose CT?
- lots of cells, fewer fibres
- lacks tensile strength, good for diffusion
- fills tissue spaces and supports vessels/nerves/glands
- lamina propria (in intestines)
What is dense CT?
- rich in fibres, fewer cells
- high tensile strength
irregular - randomly arranged fibres to resist forces in various directions (e.g. dermis of skin)
regular - linearly arranged to resist forces unidirectionally
What is unilocular adipose?
- fat in adults
- energy storage, protection and insulation
- adipocytes occupied by a single lipid droplet
What is multilocular adipose?
- more vascular, fat in new-borns
- thermogeneration
- adipocytes contain multiple lipid droplets
