Bone Dissection Lab
Purpose: To familiarize the student with structures characteristic of a long bone.
Safety: Keep hands away from sharp instruments, and be sure to disinfect all surfaces and hands that come in contact with the bones. Place all trash in the designated container.
Materials:
Beef bone: epiphysis and diaphysis (saggital and cross sectioned)
Dissecting instruments (scalpel, forceps)
Dissecting tray
Stereomicroscope
Procedure:
1. Examine a beef bone. Obtain one sample of each: diaphysis and epiphysis. Locate and identify the following structures. (You may need to utilize more than one specimen in order to identify all the structures needed.) Make a drawing or photograph and label the structures. Make a table and identify the functions of each structure.
a. Articular cartilage f. Medullary Cavity
b. Spongy Bone g. Periosteum
c. Compact Bone h. Bone Marrow
d. Diaphysis i. Epiphysis
e. Endosteum j. Epiphyseal cartilage (plate)
2. With your forceps and scalpel, remove a small portion of the periosteum from the bone’s diaphysis. Note how difficult or easy it is to remove the periosteum. Observe the tissue under a stereomicroscope and identify blood vessels within this structure. Describe your observations.
3. Look at the surface layer of a saggital section of a diaphysis, with the periosteum removed, and see if you notice any elevations, depressions, or openings into the bone. Explain the purpose of these surface markings.
4. Observe the marrow cavity of a cross section of a diaphysis by removing a small portion of the substance that fills it. Identify this substance and compare the texture of this substance as compared to the texture of the cavity that contains it. Describe your observations.
5. Observe a cross section of an epiphysis, reveal the superficial surface of the articular cartilage and compare how the superficial surface of a diaphysis compares to the surface of articular cartilage. Explain the significance of articular cartilage at a joint.
6. Return all bones to the trays and clean and dry all instruments and trays. Be sure to wash your hands with antibacterial soap, and disinfect all table surfaces.
OSTEOPOROSIS
Instructions:
1) Read the passage.
2) Use your text and/or the internet for help in answering the following questions..
The body uses calcium for things other than building bones: for regulating the cells
metabolic activity, helping the muscles to contract, and helping to control heart rate.
Calcium is transported through the circulatory system. If the concentration of calcium in
the blood gets too low, the osteoclasts release acids which dissolve the calcium in bone
which is then released into the blood. If calcium is removed faster than it is replaced, the
bones are weakened and are susceptible to fracture.
The fragile bones and the humped back that elderly persons (ie: Dowager’s Hump)
sometimes develop are caused by a gradual loss of calcium in bones. This
condition is called osteoporosis. It is more common in women than men.
Although the signs may not appear until old age, calcium loss begins early in life.
To help your skeleton to remain strong as you grow older, it is important that you – NOW –
eat a balanced diet that includes nonfat dairy, green leafy vegetables and citrus fruits.
You will be building a storehouse of calcium for the future.
Questions: Answer the following questions. Either copy the question and then answer it, or write the question as part of your answer.
1. List four things the body uses calcium for.
2. How is calcium transported in the body?
3. What can happen to your bones if they lose calcium faster than depositing calcium?
4. Provide 2 ways to ensure you have enough calcium for all your body’s needs.
5. At what age does calcium loss generally begin for women? For men?
6. When should a person begin to take precautions against calcium loss?
7. Briefly explain how the body restores the normal levels of calcium in the blood.
8. How is it possible for the bones to lose more calcium than they gain? Be specific!
9. Quite often, an elderly woman may say, “I was just standing in the middle of the floor
when I fell and broke my hip!” Do you think this sequence of events is what she thinks it is? Explain your answer.