Histology: bone and cartilage

Question 1

describe the properties of cartilage

Answer 1

semi-rigid, deformable, permeable, avascular

Question 2

describe the properties of bone

Answer 2

rigid, not permeable, vascular

Question 3

how are cartilage cells nourished

Answer 3

by diffusion through ECM

Question 4

what are cartilage cells called

Answer 4

chondrocytes

chondroblasts when immature

Question 5

where are chondrocytes located

Answer 5

in a space in the ECM called a lacuna

Question 6

what is the most common form of cartilage

Answer 6

hyaline

Question 7

what makes up the ECM of most cartilage

Answer 7

water(75%), type II collagen + proteoglycan(25%)

Question 8

what are proteoglycan aggregates made up of

Answer 8

GAGs bound to a core protein, often linked to hyaluronan

Question 9

what are the 3 different types of cartilage

Answer 9

hyaline, elastic and fibrocartilage

Question 10

describe the appearance of hyaline cartilage

Answer 10

blue-white colour and translucnet

Question 11

describe the appearance of elastic cartilage

Answer 11

light yellow in colour

Question 12

describe the appearance of fibrocartilage

Answer 12

appears white

Question 13

briefly describe properties of elastic cartilage

Answer 13

addition of elastic fibres, makes it flexible

Question 14

briefly describe the properties of fibrocartilage

Answer 14

hybrid between a tendon and hyaline cartilage

Question 15

give some examples of where hyaline cartilage is found

Answer 15

tracheal rings, articular surfaces, costal cartilage

Question 16

are bone and cartilage living or dead tissue

Answer 16

both are living tissue

Question 17

give some of the functions of bone

Answer 17

support, levers, stores Ca2+, protection of organs and blood production(haemopoiesis)

Question 18

what is bone composed of

Answer 18

bioapatite(65%), collagen(23%), water(10%), non-collagen proteins(2%)

Question 19

what is bioapatite

Answer 19

a form of calcium phosphate, mostly hydroxyapatite

Question 20

what is the diaphysis of a bone

Answer 20

the outer shell of dense cortical bone that makes up the shaft of the bone

Question 21

what is the epiphysis of a bone

Answer 21

cancellous or trabecular bone that occupies the ends(neck) of bones

Question 22

describe the appearance of cancellous bone

Answer 22

fine meshwork of bone that looks a bit like a aero bar inside

Question 23

what are the living bone cells called

Answer 23

osteocytes

Question 24

where are osteocytes located in the bone

Answer 24

in spaces called the lacunae

Question 25

what are the canals that go through the bone called that supply blood and carry away CO2 etc.

Answer 25

Volkmann’s canals = cut across the bone

Haversion canals = go through the bone

Question 26

how do the osteocytes transfer products between the canals

Answer 26

via canaliculi(tiny pores through bone extending from osteocytes)

Question 27

what type of canal does trabecular bone generally lack

Answer 27

haversion canals

Question 28

what word is used to describe the structure of trabecular and cortical bone

Answer 28

lamellar

Question 29

describe what osteoprogenitor cells are, and where they are located

Answer 29

serve as pool of reserve osteocytes, located on bone surfaces(eg periosteum)

Question 30

describe what osteoblasts are, and where they are found

Answer 30

bone forming cells, found on the surface of developing bone

Question 31

describe what osteoclasts are and where they are found

Answer 31

large multinucleated cells responsible for bone resorption, breakdown and destroy bone, found on the surface of bone

Question 32

briefly describe how bones are remodelled

Answer 32

remodelled constantly, a number of osteoclasts congregate and ‘drill’ into bone forming tunnel, osteoblasts line tunnel and lay down new bone

Question 33

what is the collection of osteoblasts and osteoclasts at the site of remodelling called

Answer 33

the basic multicellular unit(BMU)

Question 34

describe what osteoid is

Answer 34

collective term for the collagen, glycosaminoglycans(GAGs), proteoglycans and other organic compounds secreted by osteoblasts

Question 35

what type of bone is laid down when a bone fractured

Answer 35

woven bone

Question 36

how does woven bone compare to lamellar

Answer 36

not as strong as lamellar, and is therefore remodelled to lamellar bone with time