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What does sarcoplasmic reticulum do?
The Sarcoplasmic Retiulum releases calcium ions that will cause troponin/tropomyosin complex to move. This exposes the binding sites on actin and allows the cross-bridges of myosin to bind to the actin binding sites.
Which two muscle types are controlled involuntarily?
Visceral muscles, which are under involuntary control, come in two forms. They are the smooth muscle tissue and cardiac muscle tissue, found only in the heart.
How can I treat constipation by changing my diet?
To treat constipation by diet, the best way is to add more fiber in your diet to help bulk up the stool. Fiber can come from fruits, vegetables and whole grains.
What causes muscle spasms in face?
Muscle spasms in the face can come from a variety of conditions. Facial tics, stress, and tumors can all contribute to the face twitching.
If a drug caused a sudden release of large amounts of calcium in skeletal muscle from which structure would the calcium come?
sarcoplasmic reticulum
How do banding patterns change when a muscle contracts?
When a muscle contracts, the actin and myosin myofilaments come together, the H zones and I zones shrink and become very narrow. The A band does not changing during contraction.
What is the definition of a Skeletal muscle cell?
A skeletal muscle cell is a type of cell that is long, cylindrical, and striated in appearance. These cells are responsible for voluntary movement and are attached to bones by tendons. Skeletal muscle cells contract to generate force and movement in the body.
What happens to calcium ions and tropomyosin to cause a muscle to relax?
Calcium ions are pumped back into the sarcoplasmic reticulum. A free ATP will come in and restore the myosin head back to 90 degrees preparing it again for another powerstroke. It's important to note that the myosin head does NOT hydrolyze the ATP. Only in a powerstroke it will hydrolyze the ATP to use the energy to bend the myosin head 45 degrees. If there is no free ATP to release the myosin head from it's bent angle then it remains rigid. That is why when a person dies their muscles stiffen because there are no free ATP to release the myosin heads from the actin filament.
What is the sliding filament model of contraction?
The sliding filament theory is the basic summary of the process of skeletal muscle contraction. Myosin moves along the filament by repeating a binding and releasing sequence that causes the thick filament to move over the thinner filament. This progresses in sequential stages. By progressing through this sequence the filaments slide and the skeletal muscles contract and release.First Stage:The first stage is when the impulse gets to the unit. The impulse travels along the axon and enters the muscle through the neuromuscular junction. This causes full two to regulate and calcium channels in the axon membrane to then open. Calcium ions come from extra cellular fluid and move into the axon terminal causing synaptic vessels to fuse with pre synaptic membranes. This causes the release of acetylcholine (a substance that works as a transmitter) within the synaptic cleft. As acetylcholine is released it defuses across the gap and attaches itself to the receptors along the sarcolemma and spreads along the muscle fiber.Second Stage:The second stage is for the impulse spreads along the sarcolemma. The action potential spreads quickly along the sarcolemma once it has been generated. This action continues to move deep inside the muscle fiber down to the T tubules and the action potential triggers the release of calcium ions from the sarcoplasmic reticulum.Third Stage:During the third stage calcium is released from the sarcoplasmic reticulum and actin sites are activated. Calcium ions once released begin binding to Troponin. Tropomyosin blocking the binding of actin is what causes the chain of events that lead to muscle contraction. As calcium ions bind to the Troponin it changes shape which removes the blocking action of Tropomyosin (thin strands of protein that are wrapped around the actin filaments). Actin active sites are then exposed and allow myosin heads to attach to the site.Fourth Stage:The fourth stage then begins in which myosin heads attach to actin and form cross bridges, ATP is also broken down during this stage. Myosin binds at this point to the exposed binding sites and through the sliding filament mechanism the muscles contract.Fifth Stage:During the fifth stage the myosin head pulls the Actin filament and ADP and inorganic Phosphate are released. ATP binding allows the myosin to detach and ATP hydrolysis occurs during this time. This recharges the myosin head and then the series starts over again.Stage Six:Cross bridges detach while new ATP molecules are attaching to the myosin head while the myosin head is in the low-energy configuration. Cross bridge detachment occurs while new ATP attaches itself to the myosin head. New ATP attaches itself to the myosin head during this process.Stage Seven:During stage seven the ATP is broken down and used as energy for the other areas including new cross bridge formation. Then the final stage (stage 8) begins and a drop in stimulus causes the calcium concentrate and this decreases the muscle relaxation.
What does sarcoplasmic reticulum do?
The Sarcoplasmic Retiulum releases calcium ions that will cause troponin/tropomyosin complex to move. This exposes the binding sites on actin and allows the cross-bridges of myosin to bind to the actin binding sites.
How an action potential was initiated?
When muscle cells are stimulated, they contract and exert a force in one direction. Stimulation of muscle cells is caused by nerve impulses carried from the central nervous system to the muscles. When the nerve impulse reaches the end of the neuron, it causes a transfer of the action potential in muscles, which leads to a contraction.There are three types of muscle cells in the body, which are cardiac, smooth and skeletal. Cardiac muscle is only found within the heart and has its own intrinsic method for contracting, although nerves can stimulate it to speed up or slow down as necessary. Smooth muscle is found in layers surrounding the organs, and it is stimulated by the autonomic, or involuntary, nervous system. Skeletal muscle is made up of fibers and causes movement. The action potential in muscles of the skeleton is carried by the somatic, or voluntary, nervous system.Muscle cells will not contract on their own, but must be stimulated first by a nerve impulse. The axons of neurons meet muscle cells at the neuromuscular junction. To ensure that muscle contraction is simultaneous and fast, there are many neuromuscular junctions found across a muscle. All of these neurons send impulses at the same time to initiate an action potential in muscles. Having many neuromuscular junctions for each muscle allows the body to control the force of the contraction by varying the number of units that send the impulse to the muscle.When the action potential reaches the terminal end of the axon at a neuromuscular junction, vesicles fuse with the cell membrane to allow the release of a neurotransmitter - acetylcholine. The neurotransmitter spreads across the gap between the neuron and the muscle cell, until it reaches the sarcolemma, which is the membrane surrounding a muscle cell. Acetylcholine causes the permeability of the sarcolemma to change, so that sodium ions can enter and leave the membrane. This change in ions depolarizes the membrane and causes an action potential in muscles to be fired.When a muscle is at rest, tropomyosin blocks the myosin binding sites found on the actin filaments. During a contraction, myosin attaches to actin and performs a type of rowing action along the actin filaments. This causes the muscle to contract. For this to occur, myosin must be able to bind to actin, so the tropomyosin must be moved.The depolarization caused by the nerve impulse spreads across the sarcolemma and the T system - a system of tubes connected to the sarcoplasmic reticulum. Both the T system and the sarcoplasmic reticulum contain calcium ions, which are released when there is an action potential in muscles. The calcium ions diffuse throughout the muscle cell and attach to a protein called troponin, which is attached to the tropomyosin filaments found on the actin fibers. The troponin changes shape when calcium ions attach to it, which moves the tropomyosin filaments and frees the myosin binding sites along actin fibers. Myosin can now come in contact with actin and cause a muscle contraction.
Where does acetate fiber come from?
where does it come from
Where did fiber come from?
from plants....
Where does alpaca fiber come from?
Alpaca fiber comes from their fur. They have a very soft coat.
What country does olefin fiber come from?
italy
Where does flax fiber come from?
flax plants
Is there anyway to build muscle on your face to make it wider?
It will come slowly as you build muscle on the rest of your body. It will come slowly as you build muscle on the rest of your body.
