MUSCULOSKELETAL 1

Question 1

Functions of the skeleton are

Answer 1

To support, protect, enable movement, act as a reserve for calcium and phosphorous, enable haemopoiesis and fat storage.

Question 2

Axial skeleton includes

Answer 2

Skull, vertebrae, ribs.

Question 3

Appendicular skeleton includes

Answer 3

Limbs, pelvis, hands, feet.

Question 4

Organisational long bone components

Answer 4

Epiphysis, metaphysis, diaphysis, metaphysis and epiphysis.

Question 5

Contained within diaphysis

Answer 5

Compact bone, medullary cavity, periosteum, blood vessels, perforating fibers and endosteum.

Question 6

Contained within epiphysis

Answer 6

Articular cartilage, blood vessels, spongey bone, compact bone and trabeculae..

Question 7

Cells contained within bone

Answer 7

osteogenic, osteoblasts, osteocytes, osteoclasts.

Question 8

Role of the osteogenic cell

Answer 8

acts as a cell reserve

Question 9

Role of the osteoblast

Answer 9

works towards bone formation

Question 10

role of the osteocyte

Answer 10

bone maintenance

Question 11

role of the osteoclast

Answer 11

bone destruction

Question 12

Precursor to the osteogenic cell

Answer 12

Unspecialised stem cells (mesenchyme)

Question 13

Location of osteogenic cells

Answer 13

Located on the surface of bone in the periosteum and endosteum. May also be found in central canals of compact bone.

Question 14

Precursor to the osteoblast

Answer 14

Osteogenic cell

Question 15

Location of osteoblasts

Answer 15

In the layer under the peri or endosteum (active). Typically wherever new bone is being formed.

Question 16

Function of osteoblasts

Answer 16

Synthesis, deposition and calcification of osteoid.

Question 17

Precursor to the osteocyte

Answer 17

The osteoblast

Question 18

Location of the osteocyte

Answer 18

Trapped within lacunae inside bone. Osteocytes can communicate with neighbouring cells through their long cellular processes inside canaliculi

Question 19

Function of osteocytes

Answer 19

Maintenance of bone tissue:
live lattice inside bone
localised minor repair
rapid calcium exchange

Question 20

Precursor of osteoclast

Answer 20

fusion of monocyte and progenitor cells

Question 21

Location of osteoclasts

Answer 21

at sites where bone resorption is occurring

Question 22

Function of osteoclasts

Answer 22

Secretes acid and enzymes and dissolves the mineral and organic components of bone

Question 23

Where does interstitial growth occur?

Answer 23

In soft tissue, that can deform easily. Tissue bone is too rigid to grow in this manner.

Question 24

How does bone grow?

Answer 24

Using appositional growth and bone resorption. Bone can only grow by adding new bone to existing structures.

Question 25

Bone remodelling includes:

Answer 25

Appositional growth and bone resorption, two processes that can occur independent of each other.

Question 26

What are the two forms of lamellar bone?

Answer 26

Spongy bone and compact bone/

Question 27

Osteoblasts deposit new bone:

Answer 27

In layers or sheet described as lamellae. The collagen fibres are out down in the same direction within a layer, but will alternate up to 90 degrees out of phase between layers.

Question 28

What does alternating collagen placement enable?

Answer 28

Alternating collagen placement enables the bone to withstand forces from different directions, making it very strong.

Question 29

What is the first stage of primary osteon growth?

Answer 29

Osteoblasts in the active periosteum either side of the blood vessel will put down new bone forming ridges.

Question 30

What is the second stage of primary osteon growth

Answer 30

New bone continues to grow and the ridges come together and fuse forming a tunnel around the blood blood vessel.

Question 31

What is the third stage of primary osteon growth?

Answer 31

Osteoblasts in the endosteum build concentric lamellae onto the walls of the tunnel. Tunnel is slowly filled inward toward the centre- forming new osteon.

Question 32

What is the fourth stage of primary osteon growth?

Answer 32

Bone continues to grow outwards as osteoblasts in the periosteum build new circumferential lamellae.