02 - Bone, Skeleton And Joints

Question 1

What is bone?

Answer 1

A rigid connective tissue

Question 2

What are the functions of bone?

Answer 2

Protection
Movement
Attachment points
Make blood cells
Mineral storage
Energy store

Question 3

What is dense bone called?

Answer 3

Compact

Question 4

What is spongy bone called?

Answer 4

Cancellous

Question 5

Where is compact bone bound?

Answer 5

Immediately underneath the periosteum of all bones

Question 6

What is compact bone made of?

Answer 6

Repeating structural units called osteons §

Question 7

Where does cancellous bone get its strength from?

Answer 7

The trabeculae pattern

Question 8

What are the different bone classifications?

Answer 8

Long
Short
Irregular
Flat
Seasomoid
Structural (wormian)

Question 9

What defines a long bone?

Answer 9

The the shaft is longer than the diaphysis

Question 10

What defines short bones?

Answer 10

They don’t have a defined diaphysis

Question 11

What defines a seasamoid bone?

Answer 11

A bone that sits inside a tendon

Question 12

What is the function of seasamoid bones?

Answer 12

To reduce friction on bones

Question 13

What defines sutras bones?

Answer 13

They are found in the skull

Question 14

What do bones contain?

Answer 14

Abundant extra cellular matrix

Question 15

What is the extracellular matrix made of?

Answer 15

Organic matrix (30%) containing: GAGs, proteoglycans, glycoproteins, osteoconectin and osteocalcin.

Question 16

What is almost 70% of bone made of?

Answer 16

A bone mineral called hydroxyapatite

Question 17

What are the collagen fibres in bone made of?

Answer 17

Mostly type 1 collagen fibres (90%), with some type V. Only 25% of bone is water

Question 18

What is the most abundant mineral salt in bone?

Answer 18

Calcium phosphate

Question 19

Calcium phosphate combine with other mineral salts to form crystals of what?

Answer 19

Hydroxyapatite

Question 20

What is the tissue called before the extracellular matrix is calcified?

Answer 20

Osteoid tissue

Question 21

What does impaired calcification result in?

Answer 21

Higher levels of osteoid tissue than normal

Question 22

What does calcification occur only in the presence of?

Answer 22

Collagen fibres 0 salts and crystallise in the spaces between the fibres, then accumulate around them

Question 23

What is calcification initiated by?

Answer 23

Bone building cells called osteoblasts

Question 24

What is an osteoprogenitor cell?

Answer 24

An unspecialised bone stem cell derived from embryonic mesenchyme (the tissue almost all connective tissues are formed from)

Question 25

What are the bone cells that undergo cell division called and become osteoblasts

Answer 25

Osteoprogenitor cells

Question 26

Where are osteoprogenitor cells found?

Answer 26

Along the inner portion if the periosteum and endosteum

Question 27

What do mature osteoblasts become?

Answer 27

Osteocytes

Question 28

Do osteoblasts undergo cell division?

Answer 28

No

Question 29

What is an osteoblasts function?

Answer 29

Bone building cells

Question 30

What do osteoblasts do?

Answer 30

Synthesise and secrete collagen fibres and GAGs

Question 31

Where do osteoblasts become trapped and mature?

Answer 31

Extracellular matrix

Question 32

What are osteocytes and what do they do?

Answer 32

Mature bone cells | The main cell in bone tissue and maintain daily functions such as nutrient and waste exchange with blood

Question 33

Do osteocytes undergo cell division?

Answer 33

No

Question 34

What ar osteocytes and what are they formed by?

Answer 34

They are very large cells formed by the fusion of as many as 50 monocytes (white blood cell)

Question 35

Where are osteoclasts concentrated?

Answer 35

In the endosteum

Question 36

What do osteoclasts release?

Answer 36

Powerful enzymes and acids that digest the protein and mineral elements of extracellular bone matrix

Question 37

What can osteoclasts help regulate?

Answer 37

Blood calcium levels in response to certain hormones

Question 38

What is intramembranous ossification?

Answer 38

Mesenchymal models of bone form during the embryonic period and direct ossification begins

Question 39

What is endochondral ossification?

Answer 39

Cartilage models of bone form from mesenchyme during fetal period, bone then replaces cartilage

Question 40

What are the two divisions in the Skeleton?

Answer 40

Axial | Appendicular

Question 41

Do fibrous joints have space?

Answer 41

No

Question 42

Do cartilaginous joints have space?

Answer 42

No

Question 43

Do synovial joints have space?

Answer 43

Yes - a synovial cavity separating the bones

Question 44

What are the two types of fibrous joint?

Answer 44

Suture and syndesmosis

Question 45

What is the tightest of all joints?

Answer 45

Suture

Question 46

What do cartilaginous joints allow?

Answer 46

Little or no movement

Question 47

What joins the bones in joints?

Answer 47

A mix of cartilage and fibrous tissue

Question 48

What is the principle type of joint in a cartilaginous joint?

Answer 48

A symphysis

Question 49

What are synovial joints characterised by?

Answer 49

A joint (articular capsule) A ligament extending from one bone to another articulating cartilages A joint (synovial) space

Question 50

What does the articular capsule do?

Answer 50

Surrounds and reinforces the joint

Question 51

How many layers does the articular capsule have and what do they do?

Answer 51

2 - inner and outer. The inner is the synovial membrane which secretes synovial fluid. The outer is a fibrous capsule and is composed of dense CT and adheres to bone and either end of joint space

Question 52

What do ligaments connect?

Answer 52

Bone to bone

Question 53

What are ligaments composed of?

Answer 53

Collagen

Question 54

What are ligaments and how do they work?

Answer 54

They are viscoelastic structures which gradually lengthen when under tension, and return to their original shape when the tension is removed

Question 55

Are ligaments intrinsic or extrinsic

Answer 55

Both

Question 56

What does articular cartilage do?

Answer 56

Cover the ends of bones which form the joint, the cartilage protects the bone from the effects of friction and compression and their position helps maintaining joint alignment