Biomechanics Unit 2 Part 1

Question 1

What is the most abundant and widely distributed tissue in the body?

Answer 1

Connective tissue

Question 2

Four types of connective tissue are…

Answer 2

bone tissue
articular cartilage
tendon
ligament

Question 3

Three functions of bones:

Answer 3

support structures of the body, protect delicate structures like heart and lungs, and act as lever arms for movement

Question 4

Four types of bones…

Answer 4

long bones, short bones, flat bones and irregular bones

Question 5

Three components of boen tissues are…

Answer 5

osteocytes, non-cellular component and an inorganic component

Question 6

Where is ground substance found?

Answer 6

in the non-cellular organic component - collagen fibres are embedded in it

Question 7

What does the inorganic component consist of?

Answer 7

calcium phosphate crystals

Question 8

What does the inorganic component contribute to bone?

Answer 8

hardness and rigidity

Question 9

Two types of bones are called

Answer 9

compact and cancellous

Question 10

Which bone forms the outer layer?

Answer 10

compact/cortical

Question 11

Where is cancellous bone foudn in long bones?

Answer 11

metaphyses and epiphyses

Question 12

The mesh like spaces of cancellous bones contains white bone marrow

Answer 12

FALSE red bone marrow

Question 13

Basic unit of compact bone:

Answer 13

haversian system

Question 14

What are lamellae

Answer 14

cylindrical layers on bone tissue formed around a central canal called haverisian canal

Question 15

what does the haversian canal contai

Answer 15

nerve fibres and blood supply

Question 16

Where are osteocytes contained in the haversain system?

Answer 16

lacunae - small cavities between the lamellae

Question 17

What is the role of canaliculi

Answer 17

connect osteocytes to cana land other lacunae

Question 18

What surrounds the havesian system?

Answer 18

cement-like ground substance

Question 19

Basic unit of cancellous bone is:

Answer 19

Trabeculae

Question 20

Describe the arrangement of cancellous bone basic uni

Answer 20

They are arranged in a latticework of branching sheets and columns - simialr to the haversian system

Question 21

Difference between cancellous and compact basic unit

Answer 21

no haversian canal in trabeculae (cancellousbone)

Question 22

Why is there a difference between the two basic units?

Answer 22

Cancellous bone doesnt need the haversian canal as blood supply travels horguh the marrow filled spaces

Question 23

Definition of tension and example

Answer 23

when a load is acting to stretch the material like in a rope eg radius and ulna when lifting weight

Question 24

Define compression

Answer 24

load is acting to compress the material eg vertebrae under upper body weight

Question 25

Define stress

Answer 25

Force per cross-sectional area

Question 26

Define strain

Answer 26

change in length divided by the original length

Question 27

The unit of strain in Nm^-2

Answer 27

FALSE this is stress - strain ahs no units

Question 28

Why is a stress/strain curve useful

Answer 28

It can tell characteristics of a certain material (brittle, malleable, stiff, rigid…)

Question 29

Name two regions of a stree/strain curve of cortical bone

Answer 29

Elastic and plastic

Question 30

What is the point between elastic and plastic regions

Answer 30

yield point - yield stress and strain

Question 31

Describe the curve and feature in the elastic region

Answer 31

stress is directly proportional to strain - will return to original shape

Question 32

Describe the curve and feature in the plastic regio

Answer 32

curve isn’t linear, bone deforms a large amount for small increases in stress - object is permanently deformed

Question 33

What happens when the curve reaches ultimate strain and ultimate strength/strain?

Answer 33

it will fracture

Question 34

What is stress/strain

Answer 34

youngs modulus - becuase in the elastic region stress = strain x constant

Question 35

What does YM describe eg if small

Answer 35

describes ow flexible or stiff a material is eg if small then material is flexible nand small stress = large strain

Question 36

Name the 5 types of loading

Answer 36

tension, compression, bending, shear and torsion

Question 37

What is shear loading

Answer 37

it is when two forces acting in opposite directions tend to cause layers of matierla to slip/shear

Question 38

human cortical bone can withstand shear stress greater than tensile or compressive

Answer 38

FALSE other way round

- fun fact: bone is strogner in compression than tension

Question 39

Two types of bending loading

Answer 39

cantilever and three point bending x

Question 40

what is cantilever bending

Answer 40

When one end is fixed and a load is applied to the free end eg diving board

Question 41

What is three point bending

Answer 41

three forces applied to the object eg see saw

Question 42

When a structure is bent one side is ? and the other is ?

Answer 42

elongated and compressed

Question 43

What is the path of neutral axis

Answer 43

between the two sides of the structure which n deformation occurs

Question 44

Which side of a bone is more likely to fracture when bent adn why

Answer 44

The elongated side (undergoing tension) as bone is stronger in compression than tension