Lecture 5: Bones, Joints, Ligaments & Tendons

Question 1

Cartilage

Answer 1

• Supportive connective tissue
• Joint surfaces
• Ears, nose, vertebral disc

Question 2

Ligaments

Answer 2

• Dense regular connective tissue
• Anchor bones to other bones

Question 3

Tendons

Answer 3

• Dense regular connective tissue
• Anchor bones to muscles

Question 4

What type of matrix do cartilage and bone have?

Answer 4

Dense, solid matrix

Question 5

Hyaline Cartilage

Answer 5

• Proteoglycans

Question 6

Elastic Cartilage

Answer 6

• Proteoglycans and Elastin fibres

Question 7

Fibrocartilage

Answer 7

• Proteoglycans and lots of collagen

Question 8

What do all three subtypes of cartilage have in common? (hyaline, elastic, and fibrocartilage)

Answer 8

• AVASCULAR
• Contain chondrocytes residing in lacunae

Question 9

Compact Bone

Answer 9

• Dense (heavy), resists compression
• Organized in concentric circles

Question 10

Spongy Bone

Answer 10

• Light, distributes force
• Ends of long bones
• Muscles won’t have to work as hard due to combination of spongy and compact)

Question 11

Bone Tissue

Answer 11

Highly vascularized, innervated

Question 12

Bone Marrow

Answer 12

• Not a type of supportive connective tissue
• Creates blood cells

Question 13

Endosteum

Answer 13

Inner membrane of bone

Question 14

Periosteum

Answer 14

Outer membrane of bones

Question 15

Osteogenic Cells

Answer 15

Produce other bone cells

Question 16

Osteoblast

Answer 16

Produce bone matrix

Question 17

Osteocytes

Answer 17

Maintain bone matrix

Question 18

Osteoclasts

Answer 18

Dissolve bone matrix

Question 19

Cartilage can grow through what two methods?

Answer 19

Interstitial Growth - Cell division (chondrocyte proliferation)
Appositional Growth - Differentiation

Question 20

Interstitial Growth

Answer 20

1. ChondroCYTE undergoes division
2. Additional matrix secreted, pushes cells apart

Question 21

Appositional Growth (Cartilage)

Answer 21

1. Cells differentiate onto chondroblasts
2. Chondroblats secrete new matrix
3. Chondroblasts mature into chondrocytes

Question 22

What are the two mechanisms bone can grow via?

Answer 22

• Endochondral growth
• Appositional growth

Question 23

Endochondral Growth

Answer 23

1. Most bone begin (in utero) as hyaline cartilage
2. Ossification begins at the shaft (Diaphysis)
3. Ossification starts at the epiphyses (ends)
   - Not possible after puberty

Question 24

Appositional Growth (Bone)

Answer 24

• Additional circumferential lamellae are deposited and the bone continues to increase in diameter
• Osteoblast active at the periosteum
• Osteoclasts active at the endosteum

Question 25

Dermal and Sesamoid Bones

Answer 25

- Ossify from non-cartilaginous connective tissue

Question 26

Dermal Bones

Answer 26

- Found mostly in the head - Ossify within dermal tissue (dermis layer)

Question 27

Sesamoid Bones

Answer 27

- Form within tendons (EX: patella)

Question 28

Synarthrosis

Answer 28

- No movement - Fibrous: Sutures and Gomphosis - Cartilaginous: Synchondrosis (rib to sternum) - Bony: Synostosis ( middle of frontal bone)

Question 29

Amphiarthrosis

Answer 29

- Little movement - Fibrous: Syndesmosis (Ligaments) - Cartilaginous: Symphysis (Pubic Symphysis)

Question 30

Diarthrosis*

Answer 30

- Free movement - Synovial

Question 31

Synovial Joints

Answer 31

- Most complex - Involve several tissues like bone and hyaline cartilage

Question 32

Articular Cartilage

Answer 32

Sub-type of hyaline cartilage

Question 33

Bone Tissue Repairs

Answer 33

- Bone healing involves extra proliferation of cells - Typically first differentiate into cartilage (callus) Cartilage --> Spongy Bone --> Compact Bone

Question 34

Why can't articular cartilage undergo self-repair

Answer 34

Llacks perichondrium layer

Question 35

Osteoarthrotis

Answer 35

Caused by damage to articular cartilage - Damage increases friction at synovial joint leading to inflammation, pressure, and more damage

Question 36

How do bones act as a reservoir for minerals within your body?

Answer 36

- The ability of bone to be actively remodelled by cellular activity allows it to store or release minerals as they are needed

Question 37

Calcium Homeostasis

Answer 37

The balance between amount of osteoblast and osteoblast activity helps maintain calcium homeostasis