Health Blog!

Welcome students to our class blog. We will be using this space for class discussions to examine, evaluate, and share knowledge. Discussions provide opportunities for students to think critically on the topics we will be learning about in Health class. Concepts, assignments, and readings will be used as the basis for our discussions to create a positive learning community in which students are willing to share their ideas and to accept constructive criticism from their peers.

Monday, January 10, 2011

Concept Check 27.5

1. Explain how muscles work in pairs in moving limbs. Muscles need to work in pairs in order to move and go back to their starting position, because of the fact that they can only pull and not pull. When one muscle contracts it pulls the bone that is attached to it and its pair muscle relaxes.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, and sarcomere. Skeletal muscles are made up of nerves, blood vessels, and bundles of parallel muscle fibers. Within muscle fibers there are many myofibrils. These are composed of sarcomere. There are two kinds of sarcomere filaments, the thin and the thick. The thin consists of the protein actin, and the thick consists of the protein myosin.

3. Identify at least three organ systems involved in a handshake. Describe what each system contributes to the handshake.
•Nervous system: It is used to recognize a person and transmit that information to the brain, so that it starts the order to produce a handshake.
•Circulatory system: It will provide oxygen and nutrients to the muscles in the hand through the blood cells within the blood vessels.
•Muscle system: It is used to coordinate contractions and relaxations in the different muscles that will move the bones in the shoulder, arm and hand into place for the handshake.

4. Explain how actin and myosin interact as a muscle cell contracts. Myosin first binds to thin filaments called actin in every contraction, then the myosin heads bend towards the center of the sarcomere. Next ATP releases the myosin heads from the thin filaments, and they are now free to join the actin at a new place and pull it along.
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3 comments:

  1. TheaJanuary 11, 2011 at 3:33 PM

    Your answers are specific and well organized which makes it easier to understand and clearly explains the concept of each question.

    ReplyDelete
  2. Daniela CazarJanuary 11, 2011 at 3:52 PM

    I really liked that you explained the organ systems with detail. Each question answered exactly what it asked and with detail. Good job!!!!

    ReplyDelete
  3. IvoJanuary 11, 2011 at 7:02 PM

    very good answers! all questions are responded thouroughly and in detail, it helped me underestand the concept better.

    ReplyDelete

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