2 - Skeletal System

Question 1

What are the major functions of the skeletal system?

Answer 1

1. Body support
2. Organ protection
3. Body movement
4. Mineral storage
5. Blood cell production

Question 2

Describe cartilage

Answer 2

Is avascular: cellular needs are diffused to cells

Three types: hyaline, fibrocartilage, elastic

Question 3

Describe bone

Answer 3

Connective tissue

Bone matrix is composed of organic + inorganic material

Question 4

What is the organic material that makes up the bone matrix?

Answer 4

Collagen + proteoglycans

• Remains in bone tissue after removal of hydroxyapatite
  e. g lipid, carbohydrates, testosterone

Question 5

What is the inorganic material that makes up the bone matrix?

Answer 5

Hydroxypaetite

e.g water, maganese dioxide, carbon dioxide, calcium

Question 6

What is decalcification?

Answer 6

Removal of calcium

Question 7

Distinguish between tendon and ligaments

Answer 7

Tendon: Attachment of muscle to bone
Ligament: attachment of bone to bone

Question 8

What are the types of cartilage growth?

Answer 8

Appositional
- Cartilage added to exisiting cartilage
Interstitial
- Chondrocytes within matrix divide to add more matrix

Question 9

Describe the structure of hyaline cartilage

Answer 9

• Collagen fibres, evenly distributed

- Chondrocytes + chondroblasts

Question 10

Describe the function of hyaline cartilage

Answer 10

• Growth of long bones

- Allows for support and flexibility

Question 11

Describe the structure of fibrocartilage

Answer 11

• Collagen fibres

Question 12

Describe the function of fibrocartilage

Answer 12

• Compressible
• Tough
• Able to withstand pressure

Question 13

Where can fibrocartilage be found?

Answer 13

• Intervertebral discs between vertebrae

Question 14

Where can hyaline cartilage be found?

Answer 14

• Bronchi
• Rib cage
• Growing long bones

Question 15

What are the main bone cell types?

Answer 15

• Osteoblasts
• Osteoclasts
• Osteocytes

Question 16

Describe the function of osteoblasts

Answer 16

• Bone forming cells by: ossification
• Originate in periosteum
• Produce collagen and proteoglycans
• Hydroxyapatite is released when levels are low, stimulating mineralisation of matrix

Question 17

Describe the function of osteocytes

Answer 17

• When osteoblast secreted enough bone matrix to become surrounded by the cell
• Inactive, only produces components needed to maintain bone matrix
• Located in lacunae

Question 18

Describe the function of osteoclasts

Answer 18

 Reabsorption, breakdown of bone to use - Ca2+ and PO4,3- for metabolic processes
- Large multi-nucleated cells

Question 19

What is the role of collagen in bone tissue?

Answer 19

• Strength and rigidity of bone

- Without collagen, the bone would shatter

Question 20

Describe a compact bone

Answer 20

• Consists of plates: trabeculae
• Layers of trabeculae contain BVs + bone marrow
• Trabeculae consist of lamellae with osteocytes

Question 21

Describe a compact bone

Answer 21

• More matrix, denser – fewer pores

- Blood vessels enter bone

Question 22

What is the functional unit of a long bone

Answer 22

Osteon/haversian system

Question 23

Types of bones (classified by shape)

Answer 23

1. Long bones
2. Flat bones
3. Short bones
4. Irregular bones

Question 24

Describe the general structure of long bone

Answer 24

1. Diaphysis
2. Articular cartilage
3. Epiphysis
4. Epiphyseal plate
5. Periosteum
6. Endosteum

Question 25

Describe diaphysis

Answer 25

• Shaft composed of compact bone and some spongy bone
• Medullar cavity: hollow centre filled with bone marrow
   Red marrow: blood cell formation
   Yellow marrow: adipose tissue

Question 26

Describe articular cartilage

Answer 26

Found on the ends

Hyaline cartilage

Question 27

Describe epiphysis

Answer 27

• develops from centre of ossification, enlarged end of bone

Question 28

Describe epiphyseal plate

Answer 28

• between epiphysis + diaphysis when bone grows in length

Question 29

Describe peristoneum

Answer 29

• connective tissue membrane covering outer surface of bone

Question 30

Describe endosteum

Answer 30

• connective tissue membrane lining inner cavities of bone

Question 31

Describe epiphyseal line

Answer 31

• once growth stops in long bone, plate becomes ossified