Topic 7 - Connective And Adipose Tissues Flashcards
In connective tissue, ground substance + fibres = _________?
Extracellular matrix
What are functions of connective tissue?
- binding/supporting (skin), protecting/shock absorption (ribs/fat), insulating (fat), storing fuel reserve, transporting cells, separation of tissues
What is the least specialised type of connective tissue?
Loose (areolar) connective tissue
What are regular and irregular dense connective tissues?
Regular CT - fibres run parallel
Irregular CT - fibres run in all directions
What are the functions of these cells found in loose connective tissue?
- fibroblasts
- macrophages
- Mast cells
- adipocytes
- Make fibres and ground substance
- Digest stuff
- Produce granules that change tissue permeability
- Store energy in form of fats and lipids
Explain how fibroblasts work when a wound opens.
- fibroblast changes its phenotype to become a myofibroblast
- cause wound contraction to make up for tissue loss
Which are the first immune system cells to enter damaged tissue?
- neutrophils
What is in a mast cell?
Secretory granules:
Histamine - increases blood vessel wall permeability
Heparin - anticoagulant
Cytokines - attract eosinophils and neutrophils
Why are mast cells not found in the brain?
Because histamine would cause the membrane to be more leaky and so risk of water entering and cerebral oedema occurring
What’s the differences between white and brown adipocytes?
White: - Single lipid droplet - normal number of mitochondria - peripheral nucleus - energy release is slow Brown: - multiple lipid droplets - increased mitochondria - central nucleus - in infants energy release is accelerated
What are the types of fibres in connective tissue?
Collagen - multiple types, type 1 most common
Reticulin - in lymphatic tissue mainly
Elastin - made of hydrophobic amino acids, found in aorta, lungs, skin
Fibrillin - Glycoprotein essential for the production of elastin fibres
What are the function of the collagen types?
Type I - Fibrils aggregate into fibres (in tendons/ skin dermis) Type II - Fibrils do not form fibres (in hyaline and elastic cartilage) Type III (Reticulin) - fibrils form fibres around muscle and nerve and within lymphatic tissues/organs (spleen), and in tendons) Type IV - unique form in basement membrane
Functions of the types of fibres?
Collagen - Flexible with high tensile strength
Elastin - Allows tissues to recoil after distension
Reticulin - provides supporting framework/ sponge
What are Fascia/ Aponeurosis?
Fascia - thin sheath that separates muscle from other tissues
Aponeurosis - a thin sheath that connects muscle to muscle, tendon to tendon and tendon to ligament
What is a myotendinous junction?
Where muscle meets the tendon and collagens interact
Cross links between the fibres result in mechanical strength
