Lecture 3 Flashcards
What is the ECM made of
Ground substances + Cells
What is Ground substance made of?
Water, Proteins and Polysaccharides
What are the polysaccharides?
Glucosamineglycans or mucopolysaccharides
What is formed by the joining of glucosamineglycans and core proteins?
Proteoglycans
What are the repeating disaccharide units of glucosamineglycans?
Amino sugar (N.acetyglucosamine) and Uronic sugar (Glucuronic acid)
What are the sulphate GAGs
Dermatan, Heparin, Keratan, Chondroitin
What are non sulphate GAGs?
Hyaluronic acid
Why is hyaluronic acid unusual?
Its not sulphated or covalent bound to core proteins
Why are GAGs highly polar?
So they can attract water and trap it so that the ground substance is more jelly like
What are the functions of hyaluronic acid
Bind cells together, lubricates joints, maintains shape of eyeball
What are the functions of hyaluronidase?
Makes ground substance more liquid so they can move more easily in it. Makes access to egg easier for sperm
What is the function of Chondroitin
Adhesiveness of bones, cartilage, blood vessels, skin
What is the function of Keratan?
Hydrating the cornea, adhesiveness of bone and cartilage
What is the function of dermatan
Development of blood vessels, constitutes skin, tendons, heart valves
What are the features of Exophthalmos?
Goitre, autoimmune overreaction of thyroid and action of fibroblasts in ECM of eye
Why do eyes look swollen in exophthalmos?
Deposition of GAGs and influx of water
What are the three different types of protein fibers?
Collagen, Elastin and Reticular
What are the features of collagen fibers?
Strong and flexible, Parallel bundles, has different composition in different types of body tissue
Where are collagen fibers found?
Tendons, cartilage, bones and ligament
What are the features of reticular fibers?
collagen fibers with a coating of glycoproteins for strength and support, made by fibroblasts
Where are reticular fibers found?
Adipose tissue, Nerve fibres, smooth muscle tissue. These fibres branch and spread out through tissue
What are the features of Elastic fibres?
Thinner than collagen fibres, elastin surrounded by fibrillin, can be stretched 150%
Where are Elastic fibres found?
Skin, Blood vessels and lungs
How does the Marian syndrome arise?
A defect in chromosome 15 which codes for fibrillin, and thus affects elastic fibres
What are the features of individuals with Marfan syndrome?
Tall, Long limbed, protruding or collapsed sternum, weakened heart valves and arterial walls
What is the occurrence of Marfan syndrome?
1/20000
What are the two common tissue cell types?
Fibroblasts and Adipocytes
Where are fibroblasts found?
Widely distributed in connective tissue, migratory
Where are adipocytes found?
Under skin and around organs
What is the function of fibroblast cells?
Secrete components of the matrix (fibers and ground substance)
What is the function of Adipocytes?
Store fats
What are the other cell types?
Macrophages, Plasma cells, Mast cells, Leucocytes
What are the classifications of connective tissue?
Embryonic or mature
What are the two types of embryonic tissue?
Mesenchyme or Mucous
What is the structure, location and function of mesenchyme cells?
They give rise to all other connective tissues, consists of mesenchymal cells in a semi-fluid ground substance containing reticular fibre
What is the structure/location/function of Mucous cells?
Mucous CT has widely scattered fibroblasts embedded in jelly like ground substance. Supports umbilical cord of foetus
What are the 3 types of loose connective tissue?
Aoelar, Adipose and reticular
What is the structure/function/location of Aoelar connective tissue?
Three types of fibers, widely distributed around almost every structure. Strength, Elasticity, Support
What is the structure/function/location of Adipose connective tissue
Mostly Adipocytes, Central triglyceride droplet, found with areolar, white is for energy storage brown is for heat production. Insulation, Energy source, Temperature control
What is the structure/function/location of Dense regular connective tissue
found in ligaments, tendons and aponeuroses. Regularly arranged collagen, shiny white colour,
What is the structure/function/location of Hyaline cartilage?
Weak, composed of a resilient gel with fibers are present but not obvious, found in anterior ends of ribs, respiratory cartilage. Flexibility and movement
What is the structure/function/location of Compact bone
contains osteons, stores calcium and phosphorus, protection and support
What is the structure/function/location of Spongy bone
stores triglycerides, produces blood cells
What are the four cell types found in bone?
Osteogenic, Osteoblasts, Osteocytes, Osteoclasts
What are osteogenic cells?
mesenchymal cells that develop, start to lay down collagen, become trapped and become osteoblasts
what are osteoblasts?
bone forming cells. Lay down more collagen, mineralization process starts
What are osteocytes?
mature bone cells derived from osteoblasts trapped within extracellular matrix. maintains bone tissue. involved in exchange of nutrients and waste. have gap junctions
What are osteoclasts
large, multinucleated cells formed from the fusion of blood monocytes. Breaks down bone