Principles - Bones and Fractures

Question 1

What is ossification?

Answer 1

This is the process in which hyaline cartilage turns to bone in synchondroses e.g. in long bones like the humerus, femur to allow growth

Question 2

What is the structure of a long bone?

Answer 2

An epiphysis at each end
An epiphyseal growth plate at each end
Metaphysis
Diaphysis - the middle/shaft

Question 3

What is the structure of bone?

Answer 3

outer cortex - dense, strong, heavy, compact bone

inner medulla - more porous, weaker, lighter, spongy/ cancellous - bone marrow may be found here

Question 4

Where are red and white blood cells produced?

Answer 4

red bone marrow

Question 5

What is the periosteum?

Answer 5

This is the fibrous connective tissue ‘sleeve’ that covers all bones - except where there is articular cartilage e.g. joints of long bones
Vascularised
Well innervated

Question 6

Describe the process of fracture healing.

Answer 6

Fractured left clavicle
Initial healing - callus of new bone surrounding fracture line
Callus remodelling, reassuming normal shape
Healed left clavicle

Question 7

What is a callus?

Answer 7

A collection of bone and cartilage cells, mostly fibroblasts, secreting a lot of collagen, making a collar around the fractured ends of the bone, then makes a bridge.

Question 8

How can bony features develop?

Answer 8

They develop during bone growth:
1 - functional - best shape for their job
2 - an adjacent structure (e.g. blood vessel, another bone) applies a force to developing bone moulding its shape e.g. tuberosity
3 - an adjacent structure is developing at the same time as the bone - bone has to grow around the other structure e.g. forming a foramen (hole)

Question 9

Why do tibial tuberosities develop?

Answer 9

• the patella tendon pulls on that part of the one

- applies force and eventually bone grows out in that direction

Question 10

What is a tubercle/tuberosity?

Answer 10

a small rounded projection or protuberance e.g. greater tubercle of the humerus, at the proximal end of the humerus

Question 11

What is the medial malleolus?

Answer 11

The prominence on the inner side of the ankle, formed by the lower end of the tibia

Question 12

What is the floor of the cranial cavity divided into?

Answer 12

Three fossae:

anterior, middle and posterior

Question 13

What is a foraminae? (singular foramen)

Answer 13

This is a hole that cranial nerves and the brain’s blood supply passes through (into or out of the cranial cavity)

Question 14

What forms the axial skeleton?

Answer 14

Bones of the skull, neck and trunk (chest, abdomen and back)

Question 15

What forms the appendicular skeleton?

Answer 15

Bones of the pectoral girdle (scapula and clavicles), upper limbs, pelvic girdle (hip bones and sacrum), lower limb

Question 16

What are the bones of the cranial vault/neurocranium?

Answer 16

occipital bone - back 
left and right parietal bones - top 
frontal bone - front 
left and right temporal bone - temples 
sphenoid bone

Question 17

What divides the left and right parietal bones?

Answer 17

The sagittal suture

Question 18

What are the bones of the facial skeleton/ viscerocranium?

Answer 18

Left and right nasal bones - nose
Left and right zygoma - cheek bone
Maxilla - below/ next to nose
Mandible - jaw

Question 19

What are the Le Fort fractures?

Answer 19

Le Fort 1 - fracture across roots of superior teeth, quire minimal
Le Fort II - more extensive, includes nasal bone and zygoma
Le Fort III - involves most of the bones of the face, except the mandible

Question 20

Describe the mandible.

Answer 20

Mental process - chin
Angle - back of the jaw, almost a right angle
Condylar process - where the jaw articulates with the temporal bone
Coronoid process - triangular process in front of condylar process
Ramus - behind lower teeth

Question 21

How many cervical vertebrae are there?

Answer 21

7 - C1-C7

Question 22

How many thoracic vertebrae are there?

Answer 22

12 - T1-T12

Question 23

How many lumbar vertebrae are there?

Answer 23

5 - L1-L5

Question 24

How many sacral vertebrae are there?

Answer 24

5 - fused to form one sacrum

Question 25

How many coccygeal vertebrae are there?

Answer 25

4 - fused to form one coccyx

Question 26

What types of curve are there in the spine?

Answer 26

primary - curve goes in the same direction as in foetus

secondary - curve goes in opposite direction (lumbar and cervical spine)

Question 27

What are the features of a typical vertebra?

Answer 27

Spinous process - projection off the posterior

Inferior and superior articular processes - projections next to the spinous process - articulate with the vertebrae above and below

Transverse processes - projections off the side of the vertebrae

Vertebral foramen - where the spinal cord passes through

Vertebral arch - protects the spinal cord, consist of 2 pedicles and 2 lamina

Vertebral body

Question 28

What is the intervertebral foramen?

Answer 28

This forms between adjacent vertebrae - the spinal nerves emerge through here

Question 29

What is the facet joint?

Answer 29

This is the articulation between the articular processes of 2 adjacent vertebrae

Question 30

Describe the features of C1.

Answer 30

Atlas

• does not have a body or spinous process
• posterior and anterior arch instead

Question 31

Describe the features of C2.

Answer 31

Axis

• has an odontoid process
• projects superiorly from the body into C1

Question 32

Which cervical vertebra is usually the first palpable spinous process?

Answer 32

Vertebrae prominens - C7

- palpated in the midline of the posterior aspect of the neck

Question 33

Which ribs are true ribs?

Answer 33

ribs 1-7

They attach via their costal cartilage to the sternum

Question 34

Which ribs are false ribs?

Answer 34

ribs 8-10

They share cartilage and don’t articulate directly with the sternum.

Question 35

Which ribs are floating ribs?

Answer 35

ribs 11-12

They have no attachment to the sternum