Describe antagonistic muscles. How do muscles work as levers? Define origin and insertion. What ...

Answer to q. 1

Antagonistic muscles work in opposite directions. Your biceps muscle flexes your forearm, the triceps, on the other side of the arm, extends the forearm. Muscles are attached at specific spots; the origin is the area of bone where the muscle is attached that remains stationary when the muscle contracts. The insertion is the other end, where the muscle attaches to the bone that is moved. Muscles move bones like levers; the joint where the body part moves is the fulcrum, and the muscle provides the force for movement.

Answer to q. 2

Osteoporosis is a condition in which the bones become brittle, and may easily fracture. It is due to the activity of cells that remove minerals from bones, and can be seen particularly in the loss of spongy bone. Women are more susceptible to osteoporosis after menopause. Regular exercise can help prevent this loss of bone.