Lecture 32

 0%

Question 1 of 43

What are the cells in the periosteum? = Osteogenic.

Question 1 of 43

Question 2 of 43

What are the cells in the mineralised bone? = Osteocytes.

Question 2 of 43

Question 3 of 43

What are the channels in mineralised bone? = Canaliculli.

Question 3 of 43

Question 4 of 43

What are the “lakes” In mineralised bone? = Lacunae.

Question 4 of 43

Question 5 of 43

What are the cells in the endosteum? = Osteogenic.

Question 5 of 43

Question 6 of 43

What is appositional growth? = Growth out ( periosteum or endostium) by laying down bone on the surface.

Question 6 of 43

Question 7 of 43

What prevents the bone from getting too thick? = Reabsorption occurs with growth.

Question 7 of 43

Question 8 of 43

‘Where can growth occur? = Periosteum or endostium.

Question 8 of 43

Question 9 of 43

How do osteogenic cells multiply? = Mitosis.

Question 9 of 43

Question 10 of 43

When is the periosteum resting / active? = Resting → no growth. Active → growth.

Question 10 of 43

Question 11 of 43

What cells are present beneath active periosteum? = Osteoblasts.

Question 11 of 43

Question 12 of 43

What are the options for osteoblasts after growth? (3) = Osteogenic → / osteocytes / death.

Question 12 of 43

Question 13 of 43

How are cannliculli formed? = As new bone is laid down, the osteoblasts extend their cellular processes upwards.

Question 13 of 43

Question 14 of 43

How do rickets affect children? = Not enough calcium → bones ‘rubbery’ → calcified while deformed under load.

Question 14 of 43

Question 15 of 43

What is apoptosis? = Death of osteoclast.

Question 15 of 43

Question 16 of 43

Where do osetoclasts come from? = Vein → macrophage → fuse to osteoclasts.

Question 16 of 43

Question 17 of 43

What is the ruffled border of an osteoclast? = Convoluted surface of osteoclast membrane (secretory).

Question 17 of 43

Question 18 of 43

What is the clear zone? = Lip around osteoclast.

Question 18 of 43

Question 19 of 43

What are howship’s lacunae? = Empty lacumae after osteoclast leaves.

Question 19 of 43

Question 20 of 43

Why is bone growth important in younger years? = Because growth to reabsorption is about 5:1. In adults it slows significantly.

Question 20 of 43

Question 21 of 43

What is endochondral ossification? = Extension of a long bone due to interstitial growth of hyaline between epi and metaphysis.

Question 21 of 43

Question 22 of 43

What is between the epiphysis and metaphysis in a young person? = Hyaline cartilage.

Question 22 of 43

Question 23 of 43

What happens as the child grows? = Interstitial growth of hyaline cartilage, followed by ossification.

Question 23 of 43

Question 24 of 43

What happens as the child becomes a young adult? = Calcification overtakes growth, epiphysis and metaphysis fuser growth stops.

Question 24 of 43

Question 25 of 43

What are the two classes of bone (in different stages of life)? = Woven / lamellar.

Question 25 of 43

Question 26 of 43

Which is stronger? = Lamellar.

Question 26 of 43

Question 27 of 43

Why? = Multidirectional layers of the collagen.

Question 27 of 43

Question 28 of 43

In which are the collagen fibres orientated in the same direction? = Lamellar layers.

Question 28 of 43

Question 29 of 43

Why is bone layered in different directions? = Strength.

Question 29 of 43

Question 30 of 43

What is cancellors bone? (2) = Trabecular / spongy bone.

Question 30 of 43

Question 31 of 43

How many types of lamellar bone are there? = 2.

Question 31 of 43

Question 32 of 43

What is trabeculae covered with? = Endosteum.

Question 32 of 43

Question 33 of 43

Where does disease usually manifest? (in bone) = Spongy bone.

Question 33 of 43

Question 34 of 43

Why do females exhibit osteoporosis more than males? = Oestrogen decrease allows proliferation of macrophages.

Question 34 of 43

Question 35 of 43

What is themax thickness of trabeculae? = 0.4mm.

Question 35 of 43

Question 36 of 43

What are Volkmann’s canals? = Perforating canals that run perpendicular to long bone length.

Question 36 of 43

Question 37 of 43

What are central or haversian canals? = Canals running lengthwise through bone (osteums).

Question 37 of 43

Question 38 of 43

What is an osteon (haversion system)? = Cylindrical formation of bone fibres within compact bone.

Question 38 of 43

Question 39 of 43

What is inside haversian canals lined with? = Endosteum.

Question 39 of 43

Question 40 of 43

What is in the central canal? = Blood vessels.

Question 40 of 43

Question 41 of 43

What is a marker of compact bone? = Osteons.

Question 41 of 43

Question 42 of 43

How are 1o osteons formed? = During appositional growth, bone grows around blood vessels, eventually fusing periosteum to make endosteum lined canal. From there bone grows inwards towards blood vessel.

Question 42 of 43

Question 43 of 43

What is circumferential lamellae? = Bone laid down around bone not around blood vessel.

Question 43 of 43