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.

Sunday, January 9, 2011

Concept Check 27.5
1. Explain how muscles work in pairs in moving limbs.
Muscles can only pull, therefore the need an opposing muscle to return the bone in its original position, one relaxes and the other contracts pulling the bone. For a drummer beats when he pulls his arm away the triceps contracts and the biceps relaxes.
2. Identify the structures that make up a skeletal muscle.
A skeletal muscle consists of muscle fibers with nerves and blood vessels. Inside each muscle fiber are the myofibrils. Each myofibril consists of repeating units called sarcomeres. A sarcomere is made out of two filaments the thin filament called actin and the thick one called myosin it has bumplike projections called myosin heads.

3. Identify at least three organ systems involved in a handshake. Describe what each system contributes to the handshake.
Brain- directs eye sense for the presence of the other person and directs each movement involve in a handshake.
Nervous system- sends messages to muscles.
Circulatory system- provides nutrients and oxygen to hand muscles.
4. Explain how actin and myosin interact as a muscle cell contracts.
In each contraction myosin heads bind to actin. Next, myosin heads bend pulling actin to the sarcomere. ATP then binds to each myosin head releasing it from the actin. Now the myosin head can attach to another spot and pull the actin along. This process can repeat until the sarcomere is completely contracted.
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4 comments:

  1. martha menaJanuary 11, 2011 at 2:58 PM

    hi thea! i liked how you answered the third question. We can easily see the three organ systems involved and you also gave a throughly explanation of each. However, you could explain how the process ends so that the reader leaves the blog with all the possible knowledge. Keep it up!

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  2. Gaby DonosoJanuary 11, 2011 at 4:41 PM

    I like the explanation for question number 4, it explains crealy and easily to understans how myosin and actin works together along with ATP, so that contractions can occur.

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  3. Francisco OrdonezJanuary 11, 2011 at 4:50 PM

    I liked your answer for number 4 bc it helped me understand what happens in each contraction... thanks

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  4. Luis RodriguezJanuary 11, 2011 at 4:58 PM

    Your answers are complete and well done i like how you ansered question 4 because you explain the process that hapens with actin and myosin.

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