Principles - Bones and Fractures Flashcards
What is ossification?
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
What is the structure of a long bone?
An epiphysis at each end
An epiphyseal growth plate at each end
Metaphysis
Diaphysis - the middle/shaft
What is the structure of bone?
outer cortex - dense, strong, heavy, compact bone
inner medulla - more porous, weaker, lighter, spongy/ cancellous - bone marrow may be found here
Where are red and white blood cells produced?
red bone marrow
What is the periosteum?
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
Describe the process of fracture healing.
Fractured left clavicle
Initial healing - callus of new bone surrounding fracture line
Callus remodelling, reassuming normal shape
Healed left clavicle
What is a callus?
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.
How can bony features develop?
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)
Why do tibial tuberosities develop?
- the patella tendon pulls on that part of the one
- applies force and eventually bone grows out in that direction
What is a tubercle/tuberosity?
a small rounded projection or protuberance e.g. greater tubercle of the humerus, at the proximal end of the humerus
What is the medial malleolus?
The prominence on the inner side of the ankle, formed by the lower end of the tibia
What is the floor of the cranial cavity divided into?
Three fossae:
anterior, middle and posterior
What is a foraminae? (singular foramen)
This is a hole that cranial nerves and the brain’s blood supply passes through (into or out of the cranial cavity)
What forms the axial skeleton?
Bones of the skull, neck and trunk (chest, abdomen and back)
What forms the appendicular skeleton?
Bones of the pectoral girdle (scapula and clavicles), upper limbs, pelvic girdle (hip bones and sacrum), lower limb
What are the bones of the cranial vault/neurocranium?
occipital bone - back left and right parietal bones - top frontal bone - front left and right temporal bone - temples sphenoid bone
What divides the left and right parietal bones?
The sagittal suture
What are the bones of the facial skeleton/ viscerocranium?
Left and right nasal bones - nose
Left and right zygoma - cheek bone
Maxilla - below/ next to nose
Mandible - jaw
What are the Le Fort fractures?
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
Describe the mandible.
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
How many cervical vertebrae are there?
7 - C1-C7
How many thoracic vertebrae are there?
12 - T1-T12
How many lumbar vertebrae are there?
5 - L1-L5
How many sacral vertebrae are there?
5 - fused to form one sacrum
How many coccygeal vertebrae are there?
4 - fused to form one coccyx
What types of curve are there in the spine?
primary - curve goes in the same direction as in foetus
secondary - curve goes in opposite direction (lumbar and cervical spine)
What are the features of a typical vertebra?
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
What is the intervertebral foramen?
This forms between adjacent vertebrae - the spinal nerves emerge through here
What is the facet joint?
This is the articulation between the articular processes of 2 adjacent vertebrae
Describe the features of C1.
Atlas
- does not have a body or spinous process
- posterior and anterior arch instead
Describe the features of C2.
Axis
- has an odontoid process
- projects superiorly from the body into C1
Which cervical vertebra is usually the first palpable spinous process?
Vertebrae prominens - C7
- palpated in the midline of the posterior aspect of the neck
Which ribs are true ribs?
ribs 1-7
They attach via their costal cartilage to the sternum
Which ribs are false ribs?
ribs 8-10
They share cartilage and don’t articulate directly with the sternum.
Which ribs are floating ribs?
ribs 11-12
They have no attachment to the sternum
