The outer material of bones is different to the inner material, what are each called and how are they different?
- Outer cortex - dense, strong, heavy, compacted
- Inner medulla - porous, lightweight, weaker
What is the name of the bone within the medulla?
How does cancellous bone compensate for weaker areas?
The structure is organised with more "struts" in areas where more pressure is applied
Where are the areas where bone marrow is likely to be found?
1. Hip bone 2. Sternum 3. Ribs 4. Vertebrae 5. Cancellous regions of the femurand humerus
What is the function of bone marrow?
To produce red and white blood cells
What is the periosteum?
A dense envelope of connective tissue which surrounds bones, yet avoids joints and tendon articulations
During a fracture, why is the periosteum responsible for much of the pain?
It is well vascularised and innervated (also contains lymph vessels - but these don't contribute to pain)
Where do nutrient vessels enter the periosteum?
Near the middle of the bone These vessels them ramify and continue through the inner medulla
Describe the process of endochondral ossification
Process by which a small hyaline cartilage piece grows and ossifies into bone. A capillary bud initiates the ossification by creating the primary ossification centre and entering the bone
How many primary ossification centres do long bones have?
What are the 4 different parts of a long bone?
Epiphysis - rounded end Epiphyseal growth plate - hyaline cartilage plate between metaphysis and epiphysis Metaphysis - part of growth plate leding to epiphysis Diaphysis - middle section of bone
What are the 5 different classifications of bone?
1. Long bones - long and hollow 2. Flat bones - protective 3. Irregular bones - strangely shaped 4. Sesamoid bones - present within tendons 5. Shorts bones - cuboid shapes
How do fractures heal?
Weak collagen, cartilage and bony material - collectively called callus - surrounds the fracture The callus proceeds to remodel the bone to a normal shape
In what ways can a bone's shape be influenced?
1. Functional - due to genetics 2. Adjacent structures apply a force 3. Bone must grow around another structure
What is a tubercle?
A bump/small rounded area
What is a condyle?
A large rounded surface at the end of some bones
What is a fossa?
A small depression or hole
Which three fossae are present in the neurocranium?
1. Anterior cranial 2. Middle cranial 3. Posterior cranial
What are foramina?
Holes for cranial nerves and blood vessels to pass through
What is the axial part of the skeleton?
The central skeleton
What is the appendicular skeleton?
Comprised of offshoots from the axial skeleton such as arms/legs/pelvic/pectoral girdles
What are Le Fort fractures?
There are three types and all involve different sections of the facial skeleton coming separated from the main skull
How many bones make up the vertebral column?
What are the five different categories of bones in the vertebral column and how many bones are in each category?
Cervical - 7 (C1-C7) Thoracic - 12 (T1-T12) Lumbar - 5 (L1-L5) Sacral - 5 (fused together) Coccygeal - 4 (fused together, forming coccyx)
What is the distinction between primary and secondary curves of the spine?
There are 4 curve - 2 point outwards, 2 point inwards Primary point out Secondary point in
Within a vertebral body, what is the function of the vertebral arch?
To protect spinal cord Formed of 2 x lamina and 2 x pedicle
What can emerge from an intervertebral formamen?
Where do facet joints form?
Between two articular processes of two adjacent vertebral bodies
All cervical vertebrae have ___ transverse foraminae for allowing passage of _________ ________
Two Vertebral arteries
Why is C1 (atlas) unique?
It has no body or spinous process Instead it has posterior and anterior arches