Biomechanics

Question 1

Blood is Shear _______

Answer 1

Thinning

Question 2

Blood cells clump together to form a ______.

Answer 2

Rouleaux

Question 3

What are the 2 modes of fracture by which cracks can grow?

Answer 3

1. Fatigue - Caused by repeated cyclic application
2. Fast fracture - A crack rapidly propagates across a material

Question 4

What is the condition for crack propagation ?

Answer 4

Delta work >= Delta(elastic energy) + Delta(energy to increase crack size)

Question 5

Name the 2 main types of bone and state their primary difference.

Answer 5

1. Trabecular - spongy bone
2. Cortical bone - compact bone

Porosity

Question 6

Define the role of:

Osteoblasts
osteoclasts
osteocytes and lining cells

Answer 6

1. Osteoblasts - recruited to synthesise bone
2. Osteoclasts - recruited to dissolve bone
3. Osteocytes and lining cells- permanently reside in bone tissue

Question 7

What density of bone is required to be cortical ?

Answer 7

> 0.7

Question 8

Along what is cortical bone laid down ?

Answer 8

Lamellae

Question 9

Collagen fibres run _____ in cortical bone.

Answer 9

Parallel

Question 10

Cortical bone is mainly made of what ?

Answer 10

Osteonal bone which consists of cylindrically shaped structures formed from a concentric lamellae.

Question 11

Blood vessels run within a _____ . In cortical bone

Answer 11

Haversian canal