8. Connective Tissues Flashcards
What are the functions of the connective tissue blood?
Liquid tissue that’s for gas transport and immune defence functions.
What are the functions of the connective tissues cartilage and bone?
Structural functions.
What are six functions of connective tissues?
Provide substance and form to the body and organs. Provide a medium for diffusion of nutrients and wastes. Attach muscle to bone and bone to bone. Provide a cushion between tissues and organs. Defend against infection. Aid in injury repair.
What are the two components of connective tissue?
Cells and extra cellular matrix, which consists of ground substance and fibres (collagen, reticular or elastic).
Name three ways in which connective tissues difference from each other?
The type of cells they contain, the abundance and density of their cells and the constitution of their extra cellular matrix (ground substance composition and fibre type, abundance and arrangement).
What are the two embryonic connective tissues?
Mesenchyme and mucous connective tissue.
What are the two tissues classified as proper/ regular connective tissue?
Loose/ areolar or dense (irregular or regular).
What are six specialised connective tissues?
Adipose tissues, blood, cartilage, bone, lymphatic tissue and haemopoietic tissue.
How do mesenchymal cells look with H and E dye?
Tapered cells due to cytoplasmic processes. Abundant, viscous ground substance looks like lots of white.
What do mucous connective tissues look like under the microscope?
Capillaries bearing red bleed cells, specialised ground substance takes up a lot of intercellular space. The mesenchymal cells are spindle-shaped.
What are proteoglycans?
Monomers that have a core protein to which around 100 glycosaminoglycan units are joined.
What is the function of proteoglycans?
They have a high density of negative charge so attract water and form a hydrated gel.
What proportion of the whole body protein content does collagen take up?
1/4 to 1/3, it’s the commonest protein in our body.
What is gelatin?
Hydrolysed collagen.
How many type of collagen are there?
At least 28.
What is the most widely distributed type of collagen?
Type I, 90% of all collagen. Fibrils aggregate into fibres and fibre bundles.
Give a detail of type II collagen and two places it is present in.
Their fibrils don’t form fibres. It’s present in hyaline and elastic cartilage.
Where can type I collagen be found?
In tendons, capsules of organs and skin dermis.
What is reticulin?
Type III collagen. It’s fibrils form fibres around muscle and nerve cells and within lymphatic tissue and organs.
Where can type IV collagen be found?
Unique form in basal lamina of basement membrane.
What is the structure of type I collagen?
An amino acid chain where every third amino acid of the a-chain is glycine.
There are three a-chains, forming a triple helix.
Each collagen molecule is 300nm long and 1.5nm wide.
Each fibril is composed of staggered collagen molecules, periodic banding appears ever 68nm.
What are elastic fibres mare of?
Elastin and fibrillin. The elastin enfolds and is surrounded by fibrillin.
What is Marfan’s syndrome?
An autosomal dominant disorder where the expression of the fibrillin gene is abnormal so the elastic tissue is abnormal.
What are they symptoms of Marfan’s syndrome?
Sufferers are abnormally tall, have arachnodactyly (long fingers), have frequent joint dislocation and are at risk of catastrophic aortic ruptures.
