Seminar Workbook
Bones and Joints
Session Objectives.
What you will cover
• Bone structure
• Bone turnover
Your objectives are
• Describe bone structure
• Describe bone growth & development
• State ages of peak bone mass & peak density
• Describe factors responsible for adult bone health
• Bone turnover (remodelling)
• Aging & bone loss
• Describe calcium metabolism & homeostasis
• Describe fracture types
• Describe the stages of fracture repair
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Dr Marjorie L Wilson, University of Teesside, 2004
Seminar Workbook
Bones and Joints
Bone is a connective tissue, which performs a diverse range of functions.
Task
The functions of bone are given below. Match an appropriate description to the
function.
FUNCTION
1. Support
DESCRIPTION
A. Calcium and phosphate are
stored
B. synthesis of red blood cells in red
marrow
C. holds together body tissues
2. Locomotion
3. Protection
4. Erythropoeisis
D. energy reserves stored in yellow
marrow
E. act as levers to moderate
movement
F. ribs, skull, vertebrae and pelvis
shield delicate structures
5. Mineral storage
6. Lipid storage
Write answers here.
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2
3
4
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Bone shapes
Task.
Bones can be categorized according to their individual shapes.
Bone shape
Example
1. Long bones
A. found between the flat bones of the skull
2. Short bones
B. found in leg, upper and lower arm, fingers and toes
3. Flat bones
C. form the roof of the skull, the sternum and scapula
4. Irregular bones
D. carpals of hands and tarsals of feet
5. Sesamoid bones
E. spinal vertebrae, pelvic bones
6. Sutural bones
F. patella
Write answers here.
1
2
3
4
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Generic_bone04.doc
Dr Marjorie L Wilson, University of Teesside, 2004
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Seminar Workbook
Bone composition.
Task
Complete the missing words in the paragraph below. Use the words you have
been provided.
Osseous or bone tissue is a ___________________ tissue. It is a mixture of
solid ____________ and cells. Approximate components are 25% _______,
25% organic portion such as ______________ and 50% inorganic minerals
such as ___________, ___________________ and _________________.
These minerals combine together to form _________________ whose
chemical formula is Ca3(PO4)2.(OH)2.
The protein part of bone is mainly ___________. This provides bone with
flexibility but does not resist ______________. This is the function of
hydroxyapatite.
Calcium
Hydroxyapatite
Water
connective
collagen
Matrix
magnesium
compression
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Generic_bone04.doc
Dr Marjorie L Wilson, University of Teesside, 2004
protein
phosphate
Seminar Workbook
Bone tissue can either be described as compact bone or spongy bone.
Compact Bone.
Task
Complete the exercise on the structure of bone tissues using the words
provided.
Osseous
Thickest
Marrow
Flexibility
lamellae
Haversian
Stresses
Osteon
opposite
Volkmann’s
stacked
osteocytes
lacunae
osteons
tensile
Bone tissue is also known as ___________ tissue. Compact bone consists of
concentric rings of bone called _____________. Bone cells called
_______________ are located in tiny spaces called ___________, which
means ‘little lakes’. Nutrients in the blood reach these cells through blood
vessels which pass through a central _____________ canal, then via smaller
canals called the _________________ canals, which run at right angles to the
central canal. These perforating blood vessels supply nutrients to the tissues of
the __________ cavity.
The basic unit that supports compact bone is the __________ or Haversian
system. Compact bone is ___________ where stresses arrive from a limited
range of directions. Osteons are aligned in the same direction, and are
__________ on top of one another. They run parallel to the long axis of the
bone shaft. Collagen fibres in the osteons are orientated in __________
directions within the layers of the osteon. This provides the bone with
_________ strength and __________.
Bone Tissue and Homeostasis
The minerals and proteins in bone are continually being turned over and
replaced. This allows for the recycling and renewal of the bone tissue.
The continual renewal is known as remodelling. Bone remodelling is under the
control of osteoblasts, osteoclasts and osteocytes.
Task
What are the purposes of bone remodelling?
What would the consequences be if osteoclast activity were greater in bone
than the activity of osteoblasts? Why is this the case?
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Generic_bone04.doc
Dr Marjorie L Wilson, University of Teesside, 2004
Seminar Workbook
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Generic_bone04.doc
Dr Marjorie L Wilson, University of Teesside, 2004
Seminar Workbook
Bone Development - Ossification
Bone tissue begins to grow about 6 weeks after conception in the development of
the embryo. At this stage the bone is cartilaginous.
Task
What type of cartilage is found in the skeleton of the developing embryo?
There are two types of bone formation. These are:
Intramembranous ossification
Endochondral ossification
Task
Which bones are formed by intramembranous ossification?
What type of cartilage does the ossification process begin in?
Which parts of the bone form the primary and secondary ossification centres?
At what time in our development do the secondary ossification centres appear?
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Generic_bone04.doc
Dr Marjorie L Wilson, University of Teesside, 2004
Seminar Workbook
Fracture Repair
This is also a type of bone remodelling. There are four phases to the repair of a
fracture. These are:
1.
2.
3.
4.
Formation of a haematoma
Fibrocartilaginous callus formation
Bony callus formation
Bone remodelling
Task
Select the correct word to complete the sentences about fracture repair.
Extensive bleeding/bone resorption occurs when a bone is fractured and a
fracture haematoma is formed.
The fracture haematoma helps to form a/an open frame/fibrous network in
the area of the fracture.
An external callus of cartilage and bone/blood vessels and bone forms to
stabilize the break.
The internal callus/external callus helps to stabilize the inner surfaces of the
break.
Cells at the edge of the external callus differentiate into
osteoclasts/osteoblasts to build bone tissue that unites any fragments in the
bone.
The fibrocartilaginous callus stage lasts for about 3 weeks/8 weeks.
Cartilage is replaced by compact bone/spongy bone as the bone continues to
be repaired.
Bony callus formation can last 2-3 months/2-3 weeks after injury.
Evidence of a healed fracture can sometimes be recognized as a
lumpy/smooth area on the surface of the bone.
Web Pages [accessed August 2004]
http://www.bmb.psu.edu/courses/bisci004a/bone/bone.htm
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Generic_bone04.doc
Dr Marjorie L Wilson, University of Teesside, 2004