Cells & Tissues Lecture 3 Flashcards
What is connective tissue made up of?
ECM + Cells
What is ECM made up of?
GS + 3 protein fibres (secreted by cells in ECM)
What is GS made up of?
Water, proteins, polysaccharides (GAGs), protein + GAG = proteoglycans
What are GAGs?
Long unbranched polysaccharides, repeating disaccharide (amino sugar, uronic sugar, highly polar)
What are the sulphated GAGs?
Dermatan, Heparin, Keratan, Chondroitin
Non-sulphated GAGs?
Hyaluronic acid (doesn’t covalently bond to proteins)
How is GS jelly like?
Collectively GAGs trap water within their structure
What is hyaluronic acid?
Slippery substance binds cells and lubricates joints and your eyeball
What is hyaluronidase?
Produced by white blood cells, sperm to help dissolve acid, makes GS less viscous so they can move better (access easier for sperm)
Three different types of fibres found in CT?
Collagen, reticular, elastic
Collagen fibres?
Strong but flexible to resist pulling forces, 25% of proteins in your body is collagen
Reticular fibres?
Collagen in fine bundles coated in a glycoprotein, made of fibroblasts, provides strength and support, part of basal membrane, thin branching spreads through tissue
Elastic fibres?
Thin fibrous membrane, elastin covered in fibrillin to give more strength, stretched by 150%, skin, BV and lungs
What are the two types of cells found in CT?
Fibroblasts, adipocyctes
Fibroblasts?
Widely found in CT, migratory, secretes components of ECM (GS and fibres)
Adipocyctes?
Under skin and around organs (stores fat)
Two classifications of CT?
Embryonic, mature
What are the four types of bone cells?
Osteoblasts, osteoclasts, osteocyctes, osteogenic
What is an osteogenic cell?
Mesenchymal stem cell when trapped forms a osteoblasts
What is an osteoblast?
Bone forming cells
What are osteocyctes?
Mature bone cells, maintain bone tissue, involved
in exchange of nutrients and wastes, have gap junctions
What are osteoclasts?
Large, multinucleated cells formed from
the fusion of blood monocytes, break-down bone.
What is osteon?
Major unit of compact bone
What are the four parts of the osteon?
Lamellae, lacunae, canaliculi, central canal
