The Skeletal System

Question 1

What are the 5 functions of the skeletal system?

Answer 1

• Act as a framework for other structures to attach to
• Enable movement
• Protect soft tissues and organs within the body
• Play a part in haemopoiesis
• To store minerals such as calcium and phosphorus

Question 2

What 3 things is bone made of?

Answer 2

Cells
Collagen
Minerals

Question 3

What is bone matrix and what is it made of?

Answer 3

The intercellular substance of bone tissue consisting of collagen fibres, ground substance and inorganic bone salts

Question 4

What synthesises the bone matrix?

Answer 4

Osteoblasts

Question 5

What breaks down and remodels bone?

Answer 5

Osteoclasts

Question 6

What cell maintains the bone matrix

Answer 6

Osetocytes

Question 7

What does an osteoblast do?

Answer 7

Synthesises the bone matrix

Question 8

What does an Osteoclast do?

Answer 8

Breaks down and remodels bone

Question 9

What does an osteocyte do?

Answer 9

Maintains the bone matrix

Question 10

What are the two main types of bone?

Answer 10

Compact

Cancellous

Question 11

What is cancellous bone also known as?

Answer 11

Spongey bone

Question 12

Describe the structure of compact bone

Answer 12

Dense and regular
Has concentric circles = lamellae - arranged around a central canal
The haversian canal contains blood vessels and nerves

Question 13

What does the haversian canal of compact bone contain?

Answer 13

Blood vessels and nerves

Question 14

What is compact bone also known as?

Answer 14

Cortical bone

Question 15

What is cortical bone

Answer 15

The dense outer surface of the bone that forms a protective layer around the internal cavity

Question 16

What are the lamellae in compact bone

Answer 16

concentric circles around a central canal in the bone structure

Question 17

What are trabeculae in cancellous bone

Answer 17

interconnected bars of bone with spaces in between

Question 18

Which type of bone is strongest?

Answer 18

Compact bone

Question 19

Where is cancellous bone found?

Answer 19

In vertebrae
Flat bones
Ends of long bones

Question 20

How much of the skeletal system is compact bone?

Answer 20

80%

Question 21

What is Wolff’s Law?

Answer 21

states that your bones will adapt based on the stress of demands placed on them

(use it or lose it principle)

Question 22

According to Wolff’s law, what happens when you work your muscles over a long time?

Answer 22

You place stress on the bones and so the bone tissue remodels to become stronger to cope with the stress

Question 23

According to Wolff’s Law what happens to astronauts bone tissue

Answer 23

It weakens because gravity is not placing a big enough demand

Question 24

What is ossification?

Answer 24

Bone formation

Question 25

What are young animals' skeletons predominantly made of?

Answer 25

Cartilage

Question 26

What are the 2 types of ossification

Answer 26

Intramembranous Endochondral

Question 27

What is intramembranous ossification

Answer 27

the process by which bone develops from fibrous membranes to replace fibrous connective tissue

Question 28

Where does intramembranous ossification occur?

Answer 28

Flat bone i.e: skull, maxilla, mandible

Question 29

Where does endochondral ossification occur?

Answer 29

At the Physis, Epiphysis and Cuboidal bones of the CARPUS and TARSUS

Question 30

What is endochondral ossification

Answer 30

The process whereby cartilage is systematically replaced by bone to form the growing skeleton

Question 31

What are growth plates

Answer 31

The areas of new bone in children and teens – made of cartilage

Question 32

Where are most growth plates found?

Answer 32

Near the end of long bones

Question 33

What are the 4 main steps of fracture healing?

Answer 33

1) Hematoma formation 2) Fibrocartilaginous callus formation 3) Bony callus formation 4) Bone remodelling

Question 34

What happens during hematoma formation after a fracture?

Answer 34

Broken blood vessels leaks blood that clots into a fracture hematoma - blood starts to clot, forming the hematoma

Question 35

When does hematoma formation occur after a fracture?

Answer 35

Immediately

Question 36

What happens during fibrocartilaginous callus formation after a fracture?

Answer 36

internal and external calluses form - made from fibroblasts and chondroblasts Osteoblasts begin to synthesise spongy bone - forms the fibrocartilaginous callus

Question 37

What is the fibrocartilaginous callus replaced by?

Answer 37

Bony callus

Question 38

What is bony callus formation facilitated by?

Answer 38

Endochondral ossification

Question 39

What happens during bony callus formation?

Answer 39

Fibrocartilaginous callus is replaced by bony callus (cancellous bone) with the help of endochondral ossification. Remaining cartilaginous callus is reabsorbed in surrounding tissues and begins to calcify Newly formed blood vessels proliferate

Question 40

What happens during bone remodelling?

Answer 40

the bony callus (cancellous bone) is remodelled through repeated reabsorption by osteoclasts and new bone formation from osteoblasts

Question 41

How long can bone remodelling take?

Answer 41

Several months

Question 42

When does bone remodelling start?

Answer 42

3-4 weeks after the fracture

Question 43

Name 3 factors that can delay the healing of fractures

Answer 43

``` Communication Infection Tumours Disruption of vascular supply lack of calcium ```

Question 44

What can clinicians do to minimise the formation of granulation tissue and calluses

Answer 44

Reduce and fixate - moves the two ends of the fracture into close apposition

Question 45

Is bone living or lignified tissues?

Answer 45

Living

Question 46

What nutrient can be obtained from bones?

Answer 46

Calcium

Question 47

Which 3 hormones are needed for calcium homeostasis?

Answer 47

Parathyroid hormone - increases calcium in blood Calcitrol - increases calcium in blood Calcitonin - reduced amount of calcium in blood

Question 48

Which type of bone cell does calcium mainly act on?

Answer 48

Osteoclasts

Question 49

What are the 2 main types of joints?

Answer 49

Cartilaginous | Synovial