Your Skeletal System?

Question

I'm doing a project on the skeletal system.. I don't understand these 3 questions:

1. What substances are important in your skeletal system?
2. What substances does your skeletal system produce?
3. How do alcohol and drugs affect your skeletal system?

Please provide information [sites] Thanks!

Answer 1

There are several substances important in the skeletal system; one of the most important is calcium, which the body uses to form the hard part of bones. Osteoblasts produce collagen, a fibrous protein, which becomes mineralized with calcium carbonate. For a lot of really good infomation on bones, and their formation, see:
http://www.faqs.org/health/Body-by-Design-V2/The-Skeletal-System.html
Alcohol abuse tends to decrease the production of osteoblasts, and thus suppress the skeletal system in general. See:
http://pubs.niaaa.nih.gov/publications/arh24-1/27-31.pdf

Answer 2

Its 206 bones form a rigid framework to which the softer tissues and organs of the body are attached. Vital organs are protected by the skeletal system. The brain is protected by the surrounding skull as the heart and lungs are encased by the sternum and rib cage. Bodily movement is carried out by the interaction of the muscular and skeletal systems. For this reason, they are often grouped together as the musculo-skeletal system. Muscles are connected to bones by tendons. Bones are connected to each other by ligaments. Where bones meet one another is typically called a joint. Muscles which cause movement of a joint are connected to two different bones and contract to pull them together. An example would be the contraction of the biceps and a relaxation of the triceps. This produces a bend at the elbow. The contraction of the triceps and relaxation of the biceps produces the effect of straightening the arm. Blood cells are produced by the marrow located in some bones. An average of 2.6 million red blood cells are produced each second by the bone marrow to replace those worn out and destroyed by the liver. Bones serve as a storage area for minerals such as calcium and phosphorus. When an excess is present in the blood, buildup will occur within the bones. When the supply of these minerals within the blood is low, it will be withdrawn from the bones to replenish the supply.