Bone dissection
Consider the purpose of bones.
-Frame work for the body.
-As organs for the production of blood.
-Protection of vital organs.
-Mobility (joints and muscle attachment).
With these in mind, design a femur for a heavy animal. Show the external and internal shape and features of your bone.


Now we will see what the real bone looks like.

A butcher should be able to cut a cow's femur along its length. Consider the picture on the right.
Draw the external feature of the femur.
Label the:
- cartilage;
- fibrous connective tissue on the outside;
- ligaments.

 

Separate the two sections of the femur.
Draw its internal structure. Label the:
- yellow marrow;
- red marrow;
- compact bone;
- spongy bone;
- central cavity.
Solution
Research the function of the yellow and red marrow.
Why is the bone hollow?
Why are the ends of the femur composed of a porous bone structure?

 
Using a spatula, scrape out the yellow bone marrow from the central cavity.

 
Locate any blood vessel the enters the bone.

 
 The spongy bone appears red. It is honeycombed with many cavities.

 

 
An area of cartilage exists just under the surface at each end of the bone, as indicated by the arrow,
   

Active people sometimes get arthritis of the joints in later life. A joint that is commonly injured is the hip joint. A total hip replacement is often needed as the cartilage becomes totally worn out. Pain during movement becomes severe as bone rubs on bone and becomes inflamed.

New advances in medicine have enabled people with a total hip replacement to live very active life styles.

The operation is briefly summarized below.

 

 

The surgeon first makes an incision to reveal the muscles and tendons that surround the hip joint.

After cutting through these surrounding muscles and tendons the damaged femoral head is revealed.

Using a special saw the surgeon cuts away the femoral head.

A special machine bores out the acetabulum, the hip socket. The acetabular cup is then inserted and secured

The femoral component is then hammered into the femur.

The modular head is then attached.

 

 

You can view the entire operation on the right.

The femoral component is made of titanium. What are the properties of titanium that make it useful for this purpose?

The artificial joint is not as strong as the natural hip joint. Suggest reasons for this.

How many ligaments stabilise the natural hip joint?

What holds the artificial hip joint in place?

This operation is not recommended for people under 50. Why?

How has this technology improved the lives of elderly people with arthritis.

What is arthritis?

Using the knee and shoulder joints describe their structure and the ligaments that stabilise the joint. Make mention of how the particular joint is repaired when severely damaged.

What happens during a full knee reconstruction?

Describe one other breakthrough in medical science that has increased the mobility of active people after major trauma.

The hip joint is considered to be a ball and socket type of joint. Are there any other ball and socket joints in the human body and where?

Give an example of a hinged joint.