Histology: bone and cartilage Flashcards
describe the properties of cartilage
semi-rigid, deformable, permeable, avascular
describe the properties of bone
rigid, not permeable, vascular
how are cartilage cells nourished
by diffusion through ECM
what are cartilage cells called
chondrocytes
chondroblasts when immature
where are chondrocytes located
in a space in the ECM called a lacuna
what is the most common form of cartilage
hyaline
what makes up the ECM of most cartilage
water(75%), type II collagen + proteoglycan(25%)
what are proteoglycan aggregates made up of
GAGs bound to a core protein, often linked to hyaluronan
what are the 3 different types of cartilage
hyaline, elastic and fibrocartilage
describe the appearance of hyaline cartilage
blue-white colour and translucnet
describe the appearance of elastic cartilage
light yellow in colour
describe the appearance of fibrocartilage
appears white
briefly describe properties of elastic cartilage
addition of elastic fibres, makes it flexible
briefly describe the properties of fibrocartilage
hybrid between a tendon and hyaline cartilage
give some examples of where hyaline cartilage is found
tracheal rings, articular surfaces, costal cartilage
are bone and cartilage living or dead tissue
both are living tissue
give some of the functions of bone
support, levers, stores Ca2+, protection of organs and blood production(haemopoiesis)
what is bone composed of
bioapatite(65%), collagen(23%), water(10%), non-collagen proteins(2%)
what is bioapatite
a form of calcium phosphate, mostly hydroxyapatite
what is the diaphysis of a bone
the outer shell of dense cortical bone that makes up the shaft of the bone
what is the epiphysis of a bone
cancellous or trabecular bone that occupies the ends(neck) of bones
describe the appearance of cancellous bone
fine meshwork of bone that looks a bit like a aero bar inside
what are the living bone cells called
osteocytes
where are osteocytes located in the bone
in spaces called the lacunae
what are the canals that go through the bone called that supply blood and carry away CO2 etc.
Volkmann’s canals = cut across the bone
Haversion canals = go through the bone
how do the osteocytes transfer products between the canals
via canaliculi(tiny pores through bone extending from osteocytes)
what type of canal does trabecular bone generally lack
haversion canals
what word is used to describe the structure of trabecular and cortical bone
lamellar
describe what osteoprogenitor cells are, and where they are located
serve as pool of reserve osteocytes, located on bone surfaces(eg periosteum)
describe what osteoblasts are, and where they are found
bone forming cells, found on the surface of developing bone
describe what osteoclasts are and where they are found
large multinucleated cells responsible for bone resorption, breakdown and destroy bone, found on the surface of bone
briefly describe how bones are remodelled
remodelled constantly, a number of osteoclasts congregate and ‘drill’ into bone forming tunnel, osteoblasts line tunnel and lay down new bone
what is the collection of osteoblasts and osteoclasts at the site of remodelling called
the basic multicellular unit(BMU)
describe what osteoid is
collective term for the collagen, glycosaminoglycans(GAGs), proteoglycans and other organic compounds secreted by osteoblasts
what type of bone is laid down when a bone fractured
woven bone
how does woven bone compare to lamellar
not as strong as lamellar, and is therefore remodelled to lamellar bone with time
