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 Maria Alicia Jaramillo

Concept Check 27.5 Maria Alicia Jaramillo

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

Muscles in our body are only able to pull not push the attached bones, thus they need force so they can be go back to their original position. Skeletal muscles all have and opposing muscle, therefore when one muscle contracts the opposing muscle relaxes.
2. Identify the structures that make up a skeletal muscle.

  • Muscle fiber: Long cylindrical muscle that contains nuclei.
  • Myofibrils: found inside muscle fibers.
  • Sarcomere: unit that contracts in the muscle and has two kinds of filaments, thin: actin, thick:myosin.
  • Myosin: Bump like projections composed of proteins.
  • Actin: twisted structure and are made up of protein.

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

Eyes: perceive the presence of the other person and send these images or messages to the brain.

Brain: The brain sends messages to the muscles through the nerves. (control center)

Muscles: The muscles of: the back, shoulder, upper arm, forearm and wrist contract and relax during a handshake.

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

For the contractions myosin binds to the actin (thin filament), then they move towards the center of the sarcomere. ATP binds to each myosin head and releases it from the actin.

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3 comments:

  1. Pedro LeonJanuary 10, 2011 at 5:38 PM

    i like you answers. They taught me how the eyes are also used during a handshake, and also about one more structure of the skeletal muscle, the sarcomere.

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  2. Macarena MerinoJanuary 10, 2011 at 5:43 PM

    The way you expressed the information for the third question was really clear and easy to understand, it wasnt long but it is accurate and it really helps when trying to understand the roles of actin and myosin...

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  3. Camila RJanuary 10, 2011 at 7:11 PM

    In general the response to the questions were complete and explained in your own words making it easier to understand. However, question 3 asks to mentio three organ systems involved in a handshake and not necessarily three specific organs. You are mentioning the eyes, the brain and the muscles. The eyes send signals to the brain and all this happens due to the nervous system. And the muscles belong to the muscular system. You are missing one more system and I think you can include the skeletal system because 27 bones are used in a hadnshake.

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