a. Explain how muscles work in pairs in moving limbs.
While one skeletal muscle is contracting, one is relaxing.An example is when the triceps contract, biceps relax.
b. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
A skeletal muscle is made of parallel muscle fibers, blood cells, and also nerves. Myofibrils, smaller units, are found inside muscle fibers. It consists of sacromeres, which are the basic unit of action, that contract.These are made up of actin and myosin, two different filaments.The actin is a thin filament(rope like structure) and myosin is a thick filament(bumlike projections called myosin heads).
c. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
1. The brain is the main control center and is what sends the messages.
2. Through the nerves the message is sent.
3. The muscles respond and coordinate contractions and relaxations.
d. Explain how actin and myosin interact as a muscle cell contracts.
In each small contract myosin and actin bind. Then the muscle contracts when the filaments get farther or separated from one another, but when they get closer the muscle relaxes. ATP is what is used to bring actin and myosin closer or further from each other.
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