intro to connective tissue Flashcards
what are the 4 basic classes of tissues
muscles
epithelia
connective tissue
nervous tissue
examples of connective tissues
- oral cavity = different types
- bone - mineralised CT
- teeth - mineralised CT
- enamel
- dentine
- dental pulp
- periodontal ligament
what is connective tissue
term for diverse + abundant supporting tissue
what does connective tissue function in
- structural support for body + organs
- tensile strength
- elasticity
- binding tissues together
- immunodefence
- metabolism + energy store (fat cells)
- cushioning
what is connective tissue an example of
specialised connective tissue
examples of connective tissue proper
bone cartilage
blood
adipose
dentine
lymph
describe the cells of connective tissue
- fibroblasts
- main type of non-specialised connective tissue
- spindle-like cell shaped
- cigar shaped nucleus
- produce + maintain extracellular matrix (ECM) + ground substance
- activated myofibroblasts involved in wound healing → fibrosis
- can be chronically activated
describe fixed connective tissue cells
- fibroblasts
- adipocyte → fat cells - signet ring appearance
- fibrocyte
- macrophage - phagoctyosis, engulf foreign
- see fixed / resident cells in connective tissue:
- fibroblasts is connective tissue proper
- fibrocytes - inactive fibroblasts
- adipocytes - inactive fibroblasts
- macrophages - phagocytic, immune function derived from monocytes
- in specialised connective tissue such as cartilage/ bone / dentine:
- chondroblasts
- osteoblasts
- odontoblasts
where do wandering tissues migrate to + when
migrate into connective tissue when needed
describe plasma cells
oval clock face nucleus - actively produces antibodies
describe eosinophils
2 lobe nuclei
eosinophilic granules
describe neutrophils
multilobed nuclei
phagocytic functions
describe ground substance
- clear viscous like
- amorphous - doesn’t have a clear shape - instead just fills space between cells + fibres
- transparent semi solid gel
- fibres are embedded in ground substance
- hyaluronic acid backbone which contains:
- glycoproteins + complex carbohydrates-glycosaminoglycans (GAGs)
- GAFs have negative side chains-highly negative charged - acidic
- hydrophilic binds water
- provides volume to connective tissue
- allows vessels to pass through
describe lymphocyte
round nuclei with small cytoplasm
describe mast cells
basophilic granules
inflammatory reactions
histamine production
what is elastin
- secreted as precursor tropoelastin
- polymerises to become elastin
- requires glycoprotein fibrillin scaffold
where are elastin fibres found
skin
ears
arteries
lung
bladder
how can elastin be seen
- can see with H & E - esoinophilic
- elastin van geison stain - black fibres
what is the function of elastin
allows stretch + recoil to maintain shape
describe collagen
- main fibre type
- most abundant protein in the body
- high tensile strength steel
- flexible but can break
- several different types - up to 25 - superfamily
- secreted by fibroblasts as procollagen → made into tropollagen = triple alpha helix structure → fibrils
- type I - most abundant - 90%
- formation is triple alpha helix
- thicker than elastin
- doesn’t branch
- H&E - pink - eosinophilic
- masson’s trichome - blue
- EC, see fibrils + structure
- L = longitudinal
- T = transverse section
what is type I collagen found in
bones
skin
tendons
ligaments
what is type II collagen found in
cartilage
what is type III collagen found in
reticular fibres
what is type IV collagen found in
basement membrane
