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.

Tuesday, January 11, 2011

1. Explain how muscles work in pairs in moving limbs.
Muscle and with other muscle have to work in pairs to be able of working. When one contracts the other relaxes and then they change.
Tendons makes the muscle impossible to move back to their original position.

2.Identify the structures that make up skeletal muscle
Muscle fiber: contains nuclei and is a long cylindrical muscle cell.
Bundle of tissue made of Myofibrils that are found inside the muscle fibers
microfibris are made from Sarcomere which 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.

First your eyes send signal to your brain, to what they are seen might happen
Second your brain sends signals to all the muscles for the movement of the arm.
And finally they start shaking, this includes the contradiction of the brain to shake while saying hi, the hand movement, the hand moves the shoulder, and many more .


4. Explain how actin and myosin interact as a muscle cell contracts.
Myosin heads attach to the actin, they get aligned together in the center called the sacromere. This causes the muscle to contract while the other muscle relaxes, means that the myosin release from the actin of ATP.

Monday, January 10, 2011

10th Grade Health B Block: Concept check 27.5

Concept Check Juan Diego Arregui

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

All muscles have to work in pairs, as one contracts the other relaxes. 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

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

2 Myofibrils: are found inside the muscle fibers

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

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

4 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.

1 Your eyes send signal to your brain.

2 Your brain sends signals to all the muscles

3 Finally they 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.

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.

Concept check 27.5

Paula Largacha

1. Explain how muscles work in pairs in moving limbs.
A muscle can only pull and can not push, it needs another muscle to pull it back in place. This works because as one muscle contracts and pulls the other muscle is relaxed. When you want to move that body part back then the relaxed muscle will contract and the contracted muscle relax. The motion can be performed because tendons atached to the muscle pull on the bones with tendons, moving a limb.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
A skeletal muscle is made up of a mescle fiber which is a cylindrical muscle cell that contain many nuclei. A skeletal muscle is made up of many of this cells. then inside of fascicles or bundles of tissues, there are the myofibrils which are bundles of smaller units which are striped. microfibrils are made up of sarcomeres which are muscle fibers basic unit of action; this is the unit that contracts the muscle. They are composed of thin (made of actin, twisted in ropelike way) and thick (made of myosin in bumplike projection).

3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
Three organ systems working when you give a handshakes are the muscular system, the nervous system, and the circulatory system. The nervous system is the one in charge the brain decides a handshake should be made and uses nerves to make the muscular sytem start working. The muscular system contributes by moving muscles so that bones will move to make the handskake possible moving the bones. All the while the circulatory system has been working to send blood cells and oxygen to the hand muscles.

4. Explain how actin and myosin interact as a muscle cell contracts.
Myosin heads attach to thin filaments (actin) , after attaching they bend pulling muscle to the sarcomere then ATP attaches to the myosin heads release and attach at a new place until they overlap each other and reach the sarcomere.

Chapter 27.5 Daniela Torres

Concept check 27.5
1. Explain how muscles work in pairs in moving limbs.


Muscles work in pairs when moving limbs. As a muscle contracts, it pulls on the attached bone. When a skeletal muscle is contracting, there is an opposing muscle-one that is relaxed, but can still contract and pull the bone back in the opposite direction.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
An skeletal muscle is made up of a bundle of parallel muscle fibers (a fascicle), along with a supply of nerves and blood vessels. Each muscle fiber is an elongated (long) cylindrical muscle cell that contains many nuclei. Inside each muscle fiber there are bundles of smaller units called myofibrils.Each myofybril is made up of repeating units called sarcomeres. Each sarcomere is made up of two kinds of filaments: actin and myosin.

Actin is the thin rope like structure rapped around the thick filament that is myosin. Both of these filaments work together and are responsible for muscle contraction.


3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
1. First, all the main coordination occurs in the brain when the eyes sense the presence of another person and sends signal to brain.
2. Later on, the information on the brain decides to initiate the handshake.
3. The other brain regions send out messages along the nerves to an array of muscles.
4.After the response consists of a series of relaxation and contraction of various muscles from the back, forearm, shoulder, wrist, and upper arm.
5. Finally many muscles amnipulate the 27 bones in the hand.
During this whole process the nervous system contributes by sending the signals to the brain of what is happening, how, and when and how to perform the response to the signal taken.
The circulatory system contributes to this process by providing a constant supply of oxygen and nutrients through the blood vessels to make the muscles move.
Finally, the intergumentary system senses the response(the final handshake) and sends this response to the brain. plus, it protects the inner strucutres of the hand needed to perform the hand shake initiallly.

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

Actin and myosin interact as a muscle cell contracts in the following way:
1. First myosin heads bind to thin filaments.
2. Later the myosin heads bends pulling the thin filaments towards the sarcomere.
3. Later on, ATP binds to each myosin head freeing it from the thin filament.
4. By this the myosin is free to attach to a new spot and further pull the thin filament along.
5.Filaments dont get shorter; they simply just overlap each other.
6. Consequently the sarcomere shortens.
7. This process continues until sarcomere contracts.
8.As the sarcomeres of many muscle fibers shorten, the muscle contracts.
Concept Check 27.5
Camila Ruales
Block B


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

Muscles move our limbs or different body parts by contracting and the relaxing. However, they can only pull bones they are attached to by tendons, but not push them back to where they were originally, therefore they have to work in pairs. Each skeletal muscle contracting has an opposing muscle that is relaxed but then contracts pulling the bone attached to the opposite direction and then the first muscle that contracted is now relaxed. These muscles are called flexors and extensors, and as the flexor contracts, moves or bends the bone, then relaxes once the extensor contracts straightening the bone.


2. Identify the structures that make up a skeletal muscle.

The skeletal muscle is made up of thousands of parallel muscle fibers and nerves and blood vessels. Each muscle fiber is a single muscle cell that has many nuclei. They are the biggest cells in the body and are long and cylindrical. In the interior of these muscle fibers you can find bundles or packages of smaller units known as myofibrils. They have alternating light and dark stripes causing the skeletal muscle to be striated. Each myofibril is made of sarcomeres which are the muscle’s basic unit of contraction and they are made of two types of filaments. The thin filament is composed of a protein called actin and they have a twisted structure. The thick filaments are made of the protein myosin and have bulges called myosin heads.

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

Three organ systems involved in a handshake are the nervous, muscular, and skeletal system. The process starts with the nervous system, when you identify the other person's hand with your eyes and send signals to your brain which is the control center directing all your movements. Messages are transmitted trough your nerves to your muscular system and several of your muscles start a series of contractions. The muscles involved are located in your back, shoulder, upper arm, forearm and wrist. In addition, 27 bones are also involved in the process, these are moved by your muscles. Through this whole process, nutrients and oxygen reach your muscles in the blood cells carried in the blood vessels. We can see how the three organ sytems work together to enable a handshake.

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

The interaction between the two proteins composing the filaments inside the sarcomeres are the cause of the contractions. First the myosin heads attach to the thin filaments or actin and later bend, in this way they pull the actin toward the center of the sarcomere. In this step, the two types of filaments are parallel to each other and aligned. When the two types of filaments are parallel, the muscle contracts. Then, the myosin heads are released form the actin by ATP and attach to farther places and pull the thin filaments along. When this happens, the filaments are no longer parallel to each other, and the muscle relaxes. As the filaments slide along each other, the sarcomere shortens, and once sarcomeres from multiple muscle fibers shorten together, the muscle contracts. Not all myosin heads are attached to thin filament at the same time, but while some hold the actin in position, others are free to connect to new binding sites.



concept check 27.5 Pablo Martin Lucio-Paredes

1.explain how muscles work in pairs in moving lims.
when muscles function they need an opposing motion to bring the bone back to its original position, that's why they work in pairs, as one muscle contracts and other one has to relax.

2.identify the structures that make up skeletal muscle, include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
muscle fiber: single long muscle cell that contains many nuclei
myofibrils: smaller untis of a fyber
actin: protein that composes filaments
sarcomere: muscle fiber's basic unit of action
myosin: protein that composes thick filaments
sarcomere:

3. identify 3 organ systems involved in a handshake, describe what each system contributes to the handshake.
eyes: the eyes sense the other person and give the information to our brain.
brain: sends the command to start the handshake.
muscles: muscles in our back, arm, shoulder and forearm relax and stretch so the handshake can start, then many muscles manipulate the 27 bones in our hand.

4.explain how actin and myosin interact as a muscle cell contracts.
myosin binds to the actin, then move towards the center of the sarcomere, atp binds to myosin realising it from the actin

Concept Check 27.5

1. Explain how muscles work in pairs in moving limbs.
When a muscle contracts, it pulls the bone. The muscles cant push, only pull, therefore, in order to do certain movements, the muscles need to work in pairs. One muscle has to pull, and the other muscle has to relax, because it cant push. If we would only have one muscle, we could only move in one direction.
2. Identify the structures that make up a skeletal muscle.
The 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.
The eyes because it sences the presence of the other person, sending images to the brain.
The Brain, because it sends orders to the muscles to move.
The Muscles, because it needs to contract and relax in order to give a handshake.
4. Explain how actin and myosin interact as a muscle cell contracts.
The myofibrils have the actin which is the thin filament inside the myofibrils and the myosin which is the thick filament inside the myofibril.
Proteins used to work out muscle contraction.

Andrea Alarcon

Concept check 27.5
1. Explain how muscles work in pairs in moving limbs.
Muscles work in pairs because it can only pull but not push. Therefore, a muscle contracts while the other relaxes creating the movement in the limbs.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.

  • muscle fiber: single long cylindrical muscle with many nuclei.
  • myofibrils: small bundles of smaller units that are inside the mucle fiber.
  • actin: is the protein that makes up the thin filament of the sarcomere.
  • myosin: is the protein that makes up the thick filament of the sarcomere.
  • sarcomere: basic unit of action of the muscle fibers.
  • fascicle: small bundle of a nerve, tendon, or muscle fibers.

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

  • muscular system: the muscular system will be the one to allow all the muscles needed for a handshake to move.
  • nervous system: the nervous system will send the signals from the brain through the nerves to make the muscles work.
  • circulatory system: the circulatory system will provide the nutrients and oxygen to the muscles so they can work properly.

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

In each contraction, myosin heads first bind to thin filaments. Then, myosin heads bends pulling the thin filaments to the centre of the sarcomere. ATP finally realeases the myosin heads from the thin filaments allowing to bind with other filaments to make other muscle contractions.

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.

Homework Concept 27.5 Pedro Leon

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

Muscles move body parts by contracting and realaxing, by working in pairs: flexors and extensors. One muscle contracts while the other relaxes.

2. Identify the structures that make up a skeletal muscle.

They are voluntary muscles in the bones. They contain the muscle fibers (inside the muscle), the fibrils (inside the fibers), the myofibrils (inside the fibrils), and finally the actin (thin filament) and the myosin (thick filament). Both located inside the myofibrils.

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

The Intergumentary System: The sensation of the skin.
The Nervous System: The nerves react while toaching the others persons hand.
The Skeletal System: The bones move while the handshake is being made.
The Muscle System: The muscles is what do the movement.

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

Actin is the thin filament inside myofbrils, and myosin the thick filament inside the myofibrils. Both are proteins that pruduce the muscle contraction.

CONCEPT 27.5 Karolina Sotomayor

1. Explain how muscles work in pairs in moving limbs.
The muscles in our body are only able to pull the atached bones, therefore they need an opposing force so that they can go back to their original position. All skeletal muscles have an opposing muscle or pair. When one of the muscles contracts, the opposing relaxes.
2. Identify the structures that make up a 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: Thick=myosin and thin= actin.
  • Myosin: composed of proteins and have bumplike projections.
  • Actin: have a twisted structure and are composed of protein.

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

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

Brain: is the control center of the body. The brain sends messages to the muscles through the nerves.

Muscles: The muscles of the back, shoulder, upper arm, forearm and wrist perform contractions and relaxations in order to give the handshake.

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

For each contraction, the myosin head bind to the actin or thin filament, then the myosin heads bend letting the actins move towards the center of the sarcomere. ATP binds to each myosin head and releases it from the actin.

Concept check 27.5
1. Explain how muscles work in pairs in moving limbs.
Muscles can only pull not push another motion is needed to bring the bone to its original position that is why muscles work in pairs. When skeletal muscles contracte there is an opossing muscle that is relaxed but can contract and pull the bone back on its opposite direction.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
muscle fiber: single long cylindrical muscle cell that contains many nuclei.
myofibrils: bundles of smaller units.
sarcomere: unit of contraction in a muscle fiber.

Myosin: composed of proteins and have bumplike projection

Actin: have a twisted structure and are composed of protein.

3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
Brain: the main control center in your body, decides to initiate the handshake sends messages through the nerves. 
eyes: persive the presence of another person and sends this message to the brain. 
Muscles: Perform contractions and relaxations to preform the handshake. 

4. Explain how actin and myosin interact as a muscle cell contracts.
The myosin binds to the actin, then the myosin heads bend living the actins move towards the center of the sarcomere. ATP binds to each myosin head and becomes relased  from the actin.

Sunday, January 9, 2011

Fernanda Murray Concept check 27.5

Concept Check 27.5
1. Explain how muscles work in pairs in moving limbs.
As one muscle contracts the opposite one relaxes

2. Identify the structures that make up a skeletal muscle.
two types of muscle fibers: actin (the thin one) and myosin( thick one)

3. Identify at least three organ systems involved in a handshake. Describe what each system contributes to the handshake.
Nerves: eyes sense the presence of someone and thins about the handshake
Muscle: the muscles contract ( back, shoulder, upper arm, forearm, and wrist)
Bone: 27 bones are manipulated for a good hand shake

4. Explain how actin and myosin interact as a muscle cell contracts.
When actin contracts myosin doesnt move and then actin relaxes and myosin contracts

Concept Check 27.5 Macarena Merino

Concept check 27.5

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

Muscles cannot push. therefore they just pull, they need a opposing motion to return to their original position. For each skeletal muscle contracting there is an oppossing muscle with is relaxes, this muscle can contract and pull the bone in the opposite direction.

2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.

Muscle fiber:single, long cylindrical muscle cell containing many nuclei
Myofibrils:bundles of smaller units inside a muscle fiber
Actin: Protein, that makes up thin filaments.
Myosin:Protein that makes up thick filaments.
Sarcomere: unit that contracts in the muscle

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

Eyes: sense the presence of someone, something and sends these message to the brain.

Brain: The thinking part of our brain, starts the shaking. Then other regions of it, send messages to your nerves to an array of muscles.

Muscles: The muscles responde to the messages by coordinating contractions and relaxations in the muscles of your body. The brain also acts as a control center, directing the actions and moventent that handshaking involves, through nerve networks.

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

The interaction of myosin with actin is key to the contraction of muscles. To begin, myosins bin to the thin filaments. Then, the myosin head bends, pulling the actin toward the sarcomere. Then ATP binds to each of this heads. The myosin now is free to attach to a new spot and pull the thin filament. AS the filaments slide past each other, they overlap themselves, the process continues until the sarcomere is completely contracted.

Monday, January 3, 2011

Concept check 27.5

Please read section 27.5 of the online Biology book on muscles. Take notes of the reading in your Health notebook. Post your answers to concept check 27.5 on the blog and provide constructive feedback to three other learners. Constructive feedback not only means you may agree with someone else's answers or ideas but as well how those ideas may open the doors to new learning opportunities.  Due date: Jan. 11, 2011

Concept check 27.5
1. Explain how muscles work in pairs in moving limbs.
2. Identify the structures that make up a skeletal muscle. Include these terms: muscle fiber, fascicle, myofibrils, actin, myosin, sarcomere.
3. Identify at least 3 organ systems involved in a handshake. Describe WHAT each system contributes to the handshake.
4. Explain how actin and myosin interact as a muscle cell contracts.