Overview of the Locomotor Module

Question 1

How do long bones develop from cartilage

Answer 1

Cartilage is formed first. This is then invaded by red blood cells and osteogenic cells to begin the process of bone formation. Some cartilage is left behind as the growth plates and the bone gets longer, forming the epiphysis the metaphysis and the diaphysis.

Question 2

Are the cells in cartilage live or dead

Answer 2

Live

Question 3

Are the cells in bone live or dead

Answer 3

Dead

Question 4

What is an essential feature of bone growth

Answer 4

Programmed cell death (apoptosis)

Question 5

What are the three zones of the growth plate from superficial to deep

Answer 5

Proliferative, resting and hypertrophic.

Question 6

How can leg length discrepancy in children be fixed

Answer 6

If leg length discrepancy is caught before the growth plate has closed, you can remove some of the growth plate of the longer leg to slow its growth.

Question 7

What is epiphyseodesis

Answer 7

The process of removal of some of the growth plate to try and ameliorate leg length discrepancy in children.

Question 8

What is a Vargus deformity

Answer 8

Bow legs - knees point outwards

Question 9

What is a Valgus deformity

Answer 9

Knock knees - knees point inwards.

Question 10

What is arthroscopy

Answer 10

The use of a camera to look at bones.

Question 11

Which sex is at greater risk of osteoporosis

Answer 11

Females

Question 12

Why are females at a greater risk of developing osteoporosis

Answer 12

Because they start of with a lower bone mass and bone mass decreases quicker after menopause due to the loss of protective oestrogen.

Question 13

What does osteoporosis increase risk of

Answer 13

Fracture

Question 14

What are the primary causes of OP

Answer 14

Age, menopause, decreased renal function

Question 15

What are the secondary causes of OP

Answer 15

Endocrine malnutrition and immobilisation.

Question 16

What is rheumatoid arthritis

Answer 16

A chronic inflammatory condition

Question 17

What happens in osteoarthritis

Answer 17

Articular cartilage surrounding the ends of long bones is worn away.

Question 18

Why is repair of connective tissue so poor

Answer 18

• Poor vascular supply
• Limited nutrient supply
• Loss of cell matrix interactions

Question 19

What are the four basic tissue groups

Answer 19

Epithelia, neural, connective and muscle.

Question 20

How much of the body weight is made up by connective tissue

Answer 20

50%.

Question 21

What are the three key components of the ECM

Answer 21

Fibres, ground substance and interstitial fluid.

Question 22

What is an example of a fibre in the ECM

Answer 22

Collagen

Question 23

What makes up the ground substance

Answer 23

Proteoglycans.

Question 24

What are the three types of cartilage

Answer 24

Hyaline, fibro-cartilage and elastic.

Question 25

What are the two types of bone

Answer 25

Cancellous and compact

Question 26

Which three types of tissue do not strictly comply with the definition of a connective tissue

Answer 26

• Adipose tissue as the cells are close together within the matrix
• Lymph and blood as the fluid in which the cells are suspended was not synthesised and secreted by the cells themselves.

Question 27

Which type of force is collagen good at withstanding

Answer 27

Tensile forces.

Question 28

What type of force is collagen bad at withstanding

Answer 28

Compressive forces.

Question 29

What type of force are proteoglycans good at withstanding

Answer 29

Compressive forces

Question 30

What type of force are proteoglycans bad at withstanding

Answer 30

Tensile forces.

Question 31

What are examples of resident cells in connective tissues

Answer 31

• Fibroblasts in most connective tissues
• Chondrocytes in cartilage
• Osteoblasts, osteoclasts and osteocytes in bone

Question 32

What is the role of osteoblasts

Answer 32

Lay done new bone

Question 33

What is the role of osteoclasts

Answer 33

Remove bone.

Question 34

What is the role of osteocytes

Answer 34

To maintain bone matrix and assist bone repair.

Question 35

How do resident cells link to the ECM

Answer 35

Integrins

Question 36

What are examples of immigrant cells in connective tissues

Answer 36

Macrophages, lymphocytes, neutrophils, mast cells.

Question 37

What is the function of fibroblasts

Answer 37

To synthesise and secrete components of the ECM.

Question 38

Which type of collagen do fibroblasts mainly secrete

Answer 38

Type I collagen

Question 39

What is secreted by fibroblasts into the ECM

Answer 39

Collagen (mainly type I), elastin, fibrillin and proteoglycans (mainly small PGs)

Question 40

What is the morphology of chondrocytes

Answer 40

This varies. The chondrocytes at the surface of cartilage tend to be flat while those deeper tend to be round.

Question 41

What is the function of chondrocytes

Answer 41

Synthesis, secretion and turnover of the ECM. They produce some degradative enzymes.

Question 42

What is secreted by chondrocytes into the ECM

Answer 42

Collagen (mainly type II), and proteoglycan (aggrecan). Degradative enzymes are also secreted - cathepsins, collagenases, metalloproteinases and their inhibitors - TIMPS - issue inhibitors of metalloproteinases.

Question 43

What is the main type of collagen secreted by chondrocytes

Answer 43

Type II collagen.

Question 44

What are proteoglycans composed of

Answer 44

Glycosaminoglycans (GAGs)

Question 45

What does the composition of the interstitial fluid depend on

Answer 45

The proteoglycans as these are negatively charged to attract positively charged cations and repel negatively charged anions.

Question 46

What is the basketweave structure of articular cartilage

Answer 46

Proteoglycans are contained within a basketweave structure. The basketweave structure consists of type 2 collagen joined by type 9 collagen.