Skeletal System

Question 1

Define bone remodelling.

Answer 1

The ongoing replacement of old bone tissue by new bone tissue. consists of 2 processes.

Question 2

Name the two processes involved in bone remodelling and what they do.

Answer 2

• bone deposition (addition of minerals and collagen fibres by osteoblasts)
• bone resorption (removal of minerals and collagen by osteoclasts)

Question 3

List four bone cells that contribute to bone remodelling

Answer 3

• osteoprogenitor cells
• osteoblasts
• osteocytes
• osteoclasts

Question 4

How do osteoprogenitor cells contribute to bone remodelling?

Answer 4

involved with cell division to become an osteoblast

Question 5

How do osteoblasts contribute to bone remodelling?

Answer 5

bone formation - secrete collagen fibres and other organic components to build ECM (deposition)

Question 6

How do osteocytes contribute to bone remodelling?

Answer 6

• maintain daily metabolism

* maintain mineral concentration of matrix

Question 7

How do osteoclasts contribute to bone remodelling?

Answer 7

breakdown ECM (resorption, regulate calcium)

Question 8

List the four zones that are present in the EPIPHYSEAL PLATE of a long bone.

Answer 8

• zone of resting cartilage
• zone of proliferating cartilage
• zone of hypertrophic cartilage
• zone of calcified cartilage

Question 9

What occurs on the epiphyseal side of the epiphyseal plate during growth in length? (Include cells involved)

Answer 9

• interstitial growth of cartilage (mitosis)

* chondrocytes proliferate

Question 10

What occurs on the diaphyseal side of the epiphyseal plate during growth in length? (Include cells involved)

Answer 10

• replacement of cartilage
• osteoclasts dissolve calcified cartilage
• invasion of osteoblasts to build bone

Question 11

Which part of the long bone increases in length?

Answer 11

diaphysis

Question 12

What are the four phases of bone fracture repair?

Answer 12

• Phase 1 - reactive
• Phase 2a - reparative
• Phase 2b - reparative
• Phase 3 - remodelling

Question 13

Describe one event that occurs in PHASE 1 of bone fracture repair.

Answer 13

reactive - inflammation occurs bringing phagocytes to the area and osteoclasts remove damaged tissue

Question 14

Describe one event that occurs in PHASE 2a of bone fracture repair.

Answer 14

reparative - chondroblasts produce fibrocartilage used to build a soft callus that bridges the fracture

Question 15

Describe one event that occurs in PHASE 2b of bone fracture repair.

Answer 15

reparative - osteoprogenitor cells develop into osteoblasts that produce spongy bone that forms a hard callus

Question 16

Describe one event that occurs in PHASE 3 of bone fracture repair.

Answer 16

remodelling - dead portions of fragments reabsorbed by osteoclasts

Question 17

Why does healing occur faster in bone than cartilage?

Answer 17

because bone has blood vessels, cartilage does not

Question 18

List the two criteria that structural classification (of joints) is based on.

Answer 18

• based on structural classification (presence of absence of synovial cavity + type of connecting tissue
• based on functional classification (based on movement)

Question 19

Name the three STRUCTURAL classifications

Answer 19

• fibrous
• cartilaginous
• synovial

Question 20

Describe FIBROUS structural classification of joints

Answer 20

• no synovial cavity

* dense, fibrous connective tissue

Question 21

Describe the CARTILAGINOUS structural classification of joints

Answer 21

• no synovial cavity

* fibrocartilage or hyaline cartilage

Question 22

Describe SYNOVIAL structural classification of joints

Answer 22

• contains synovial cavity

* hyaline cartilage called articular cartilage

Question 23

Name three FUNCTIONAL classifications of joints

Answer 23

• synarthrosis
• amphiarthrosis
• diarthrosis

Question 24

Describe SYNARTHROSIS

Answer 24

immovable fixed joint between bones connected by fibrous tissue
eg sutures of skull

Question 25

Describe AMPHIARTHROSIS

Answer 25

a joint with limited mobility eg between vertebrae

Question 26

Describe DIARTHROSIS

Answer 26

freely movable joint | eg elbow

Question 27

List the movements that occur in each structural classification of joints

Answer 27

* synarthrosis - immovable * amphiarthrosis - slightly moveable * diarthrosis - freely movable