Connective and Adipose Tissues Flashcards
What are the main cells in connective tissue?
Fibroblasts
Chondrocytes
Osteocytes/osteoblasts/osteoclasts
Stem cells/progenitor cells/bone marrow/blood/adipocytes
What are the main products of connective tissue?
Fibres
Ground substance
Wax and gel-like materials
Give example of fibres found in connective tissue.
Collagen, reticulin, elastin, fibrillin, fibronectin, laminin
What are the functions of the connective tissue.
Binding and support Protection Insulation Energy storage Transporting substances via blood and interstitium Separation of tissues
What are the two main types of connective tissue?
Loose connective tissue and dense connective tissue.
What are the two subtypes of dense connective tissue?
Irregular and regular. Regular runs in parallel.
What are the special features of loose connective tissue?
Multiple cells, contain of 2 main fibres and gel-like extra cellular matrix.
What are the cells found in loose connective tissue?
Fibroblasts, macrophages and other white blood cells and mast cells.
What are the two main fibres found in loose connective tissue?
Collagen and elastic fibres.
What are example of the gel-like extracellular matrix / ground substance found?
Proteoglycans and hyaluronic acid
What are the functions of loose connective tissue?
Cushions and stabilises organs
Holds vessels that supply fluids
Permits cell migration
Inflammation pathways
Where can loose connective tissue be found?
Usually under epithelial cell layers (e.g. lamina propria)
Around glands
Surrounding capillaries, nerves and sinusoids
What are fibroblasts?
Cells that synthesise and secrete the fibres that lie within the ground substance (ECM).
They are important for wound healing and formation of scar tissue.
What are myofibroblasts and what are they used for?
Modified fibroblasts that contain actin and myosin. They are responsible for wound contraction when tissue loss has occurred.
What are macrophages?
Immune system cells that are phagocytic. Present foreign material to T lymphocytes of the immune system.
What are mast cells?
Cells containing abundant granules of histamine, heparin and cytokines that attract eosinophils and neutrophils.
Where can mast cells be found?
In areolar connective tissue near blood vessels.
Absent from CNS to avoid damaging effects of oedema there.
What are the two types of adipocytes? How do they differ structurally?
White adipocytes and brown adipocytes.
WA has their organelles, nucleus and cytoplasm all squeezed to one side, they also have low levels of mitochondria. Also one large single lipid droplet.
BA has their organelles, nucleus and cytoplasm all squeezed to the centre. A lot of mitochondria and multiple small lipid droplets.
What are the functions of adipocytes?
Padding and shock absorber. Also insulation and energy reserve.
Where can you find white adipocytes?
Throughout the body
Where can you find brown adipocytes?
Mainly on the upper back, not really anywhere else in adults. Brown adipose tissue is generally only found in neonates and young children but disappear as you grow older.
Why is brown adipocytes present in neonates?
Because neonates can’t shiver, this is where they get their heat from. Lipid breakdown is accelerated from BA.
Over 90% of all collagen in the body is one specific type? Which?
Type 1
What different types of collagen are the main types found in the body?
Type 1 Type 2 Type 3 Type 4 Type 5
Where can type 1 be found and what are their structure?
Fibrils aggregate into fibres and fibre bundles. Found in tendons, skin, organs and bones.