Bone and Cartilage

Question 1

What are the cells involved in cartilage production?

Answer 1

Chondroblasts

Question 2

How does cartilage receive oxygen and nutrients?

Answer 2

Long range diffusion

Question 3

What is the name of the compartments where chondrocytes are found?

Answer 3

Lacunae

Question 4

What substances do chondroblasts produce?

Answer 4

Fibres and ground substance

Question 5

What are the three types of cartilage?

Answer 5

Hyaline, Elastic and Fibrocartilage

Question 6

Where is hyaline cartilage located in the body (4 in total)

Answer 6

Articular surfaces of bone
Trachea and bronchus
Costal cartilages
Nasal cavity and nose

Question 7

Where is elastic cartilage located in the body (2 in total)

Answer 7

Pinna of external ear

Epiglottis

Question 8

Where is fibrocartilage located in the body (4 in total)

Answer 8

Tendon insertions
Pubic symphysis
Intervertebral discs
Articular menisci (knee joint)

Question 9

What is the name of the CT capsule surrounding cartilage (absent in fibrocartilage)

Answer 9

Perichondrium - Dense regular connective tissue

Question 10

What is the main function of hyaline cartilage?

Answer 10

Shock absorption

Question 11

What are the main components of hyaline cartilage?

Answer 11

Collagen type II fibres embedded in a firm hydrated gel of proteoglycans and structural glycoproteins

Question 12

What are the main fibrous components of elastic cartilage?

Answer 12

Collagen type II and elastic fibres

Question 13

What is the structure of fibrocartilage?

Answer 13

Chondrocytes arranged in straight rows separated by collagen type I fibres

Question 14

What is the main function of fibrocartilage?

Answer 14

Combines tensile strength with shock absorption: Resists compression

Question 15

What are the main functions of bone (6 in total)

Answer 15

1. Protects internal organs
2. Stores and releases fat
3. Produces blood cells
4. Stores and releases nutrients
5. Facilitates movement
6. Supports body

Question 16

What comprises the bone matrix?

Answer 16

1. Collagen type I (95% of organic matrix)

2. Proteoglycan aggregates and specific glycoproteins (5% of organic matrix)

Question 17

What form is calcium bound to the bone matrix?

Answer 17

Calcium phosphate in the form of hydroxyapatite crystals

Involved in the mineralisation of bone

Question 18

What are the three bone cells?

Answer 18

1. Osteoblasts
2. Osteocytes
3. Osteoclasts

Question 19

What is the main function of osteoblasts?

Answer 19

Forms the bone matrix

Question 20

What is the main function of osteocytes?

Answer 20

Maintains the bone matrix

Question 21

What is the main function of osteoclasts?

Answer 21

Resorb bone

Question 22

Where are active osteoblasts required for?

Answer 22

Required before the osteoid material can be deposited

Osteoid is the unmineralised component of the bone

Question 23

What is the unmineralised component of bone?

Answer 23

Osteoid

Question 24

Where are osteoblasts located?

Answer 24

On the surfaces of bone tissue

Question 25

What is the progenitor cell of osteoblasts/osteocytes?

Answer 25

osteoprogenitor cell

Question 26

What is the name of the small channels that connect lacunae in bone?

Answer 26

Canaliculi

Question 27

What is the function of canaliculi?

Answer 27

Permit the flow of nutrients and oxygen through the bone matrix

Question 28

Where are osteocytes located?

Answer 28

In lacunae within the mineralised matrix

Question 29

How do osteoclasts resorb bone material?

Answer 29

They release enzymes such as collagenase and by dissolving calcium salt crystals

Question 30

From what cells are osteoclasts derived?

Answer 30

Monocyte phagocyte lineage

Question 31

Where are osteoclasts located?

Answer 31

Sit on the bone surface in depressions known as HOWSHIP'S LACUNAE

Question 32

What is a distinct feature of osteoclasts?

Answer 32

The cell surface in contact with bone is highly folded, forming a RUFFLED BORDER (increases the surface area for maximum bone resorption)

Question 33

What are the two types of bone?

Answer 33

Compact bone and spongy bone

Question 34

Give another name for compact bone

Answer 34

Cortical bone

Question 35

Give two other names for spongy bone

Answer 35

Trabecular or cancellous bone

Question 36

Describe the structure of compact bone

Answer 36

Dense areas without cavities Collagen fibres are organised in concentric lamellae around a canal containing blood vessels and nerves. These are known as Osteons or a Haversian system

Question 37

Give two names for a unit (circle thing) in compact bone

Answer 37

Osteon | Haversian system

Question 38

What is in the centre of a Haversian system?

Answer 38

Haversian canal

Question 39

What passes though the Haversian canal in compact bone?

Answer 39

Blood vessels and nerve

Question 40

Describe the structure of spongy bone

Answer 40

Areas with numerous interconnecting cavities Absent of osteons

Question 41

How is spongy bone organised?

Answer 41

Spongy bone is organised into plates of bone called trabeculae/spicules. The Lamella within the trabeculae are arranges concentrically with no central canal

Question 42

What is the connective tissue layer that surrounds bone

Answer 42

Periosteum

Question 43

What is the periosteum comprised of?

Answer 43

Dense irregular connective tissue and osteoprogenitor cells

Question 44

What connects the periosteum to the underlying bone matrix?

Answer 44

Sharpey's fibres (bundles of collagen fibres)

Question 45

What is the endosteum comprised of?

Answer 45

A single layer os osteoprogenitor cells and a very small amount of connective tissue

Question 46

What is the function of the periosteum and the endosteum?

Answer 46

To provide nutrients to the bone tissue and provision of new bone cells.