Concept Check Nicole De Francisco

1. Explain how muscles work in pairs in moving limbs.

All muscles have t work in pairs, as one contract the other relaxes. Since tendons don’t allow muscles to go back to their original position it is fundamental that these work in pairs.

2.Identify the structures that make up skeletal muscle

Muscle fiber: contains nuclei and is a long cylindrical muscle.

Myofibrils: are found inside the muscle fibers

Sarcomere: is the unit that contracts in the muscle and has two kinds of filaments

Myosin: composed of proteins and have bump like projections. Thick

Acting: have a twisted structure and are composed of protein. Thin

3. Identify at least three organ systems involved in a handshake. Describe what each system contributes to a handshake.

The 3 systems involved are muscular, nervous and skeletal.

You start with your eyes that are part of the nervous, they send signal to your brain.

Now your brain sends signals to all the muscles to start shaking, this includes the contradiction of many skeletal systems, your shoulder, back, arms, etc.

4. Explain how actin and myosin interact as a muscle cell contracts.

Myosin heads attach to the actin, here they get aligned together in the center that is called the sacromere. This causes the muscle to contract. When the muscle relaxes, means that the myosin release from the actin because of ATP.