Explain The Process Of Muscle Contraction

As result, the bonding causes the sodium and potassium gates to open. As result, end plate potential is formed and excites areas of muscle tissue. Action potential is created and the muscle moves or contracts.

Muscle contraction can be understood as the consequence of a process of transmission of action potentials from one neuron to another. A chemical called acetylcholine is the neurotransmitter released from the presynaptic neuron. As the postsynaptic cells on the muscle cell membrane receive the acetylcholine, the channels for the cations sodium and potassium are opened. These cations produce a net depolarization of the cell membrane and this electrical signal travels along the muscle fibers. Through the movement of calcium ions, the muscle action potential is taken into actual muscle contraction with the interaction of two types of proteins, actin and myosin.

If acetylcholine is not liberated than it would also not cause an action potential which would not cause a muscle contraction.

-Sarcoplasmic Reticulum (SR) then releases Calcium which binds to troponin in the thin filament, exposing myosin-binding sites;

The components of the nervous system involved in the skeletal muscle movement is the motor division. The motor impulse moves through the body by traveling through efferent fibers. A motor unit is a neuron and also that is where all the other muscle fibers are connected.

How is contraction ended? Ach is released and binds to receptors on the motor end plate, then an action potential is produced which releases Ca+. The Ca+ binds to troponin, then myosin binds to actin to form crossbridges. The myosin pulls the actin then releases from actin and ADP is bound to the myosin.

As a result of the contractions in the Muscle- Skeletal Longitudinal Section cells and the Muscle- Skeletal Cross Section cells, it allows your muscle to be able to contract in response to nerve stimuli. This means that the movements of most of these muscles are not involuntary, you can control them. Therefore, once the stimulation stops, the muscles relax.

The power stroke is responsible for the contraction of the muscle and force generation. ATP binding to the myosin head detaches the myosin head from the actin filament and allows the cycle to repeat. The coordinated contraction and relaxation of many muscles in an antagonistic fashion is the basis for the kinematics of any movement.

The structure of neuromuscular junction consists of a neuron and skeletal muscle cell. The motor neurons, which arise from the spinal cord, supply the skeletal muscle fibers. The neuromuscular junction is un-myelin nerve with a bulb shape at the endings that contract the muscle fiber. The schwann cells form a covering over the postsynaptic membrane and nerve membrane of the fiber that is located under the terminal and is categorized as a post-junction folds. The area between the folds and the bulbs create the synaptic cleft. This consists of proteins and proteoglycans. The enzyme acetylcholinesterase; exist only at high levels in the synaptic basal lamina (UMN,

and finger ability to flex and bend is due to the anterior muscles while the posterior muscles work to

As the message arrives at the end of the nerves, the message is transmitted to the muscles. Before the message is transmitted to the muscles it has to pass the space between the end of the nerve and the muscle, and that space is called neuromuscular junction. The message is transmitted from the brain to the end of the nerve and from the nerve to the neuromuscular junction, and when the message arrives the chemical called neurotransmitters are released.

2. What occurs in the muscle during this apparent lack of activity? Ca++ is being released from the sacroplasmic reticulum and filament movement is taking up slack.

Thoughts that started in the cerebral cortex as synapses between unmylientated neurons of many brilliant gentleman. These synapses traveled to other parts of the brain to turn into synapses that signal movement of certain muscle fibers. Movement that occurs by a signal accompanied by chemical elements traveling down millions of dendrites, myelinated axons, and axon terminals. They reach the muscle fibers where synaptic vessels release acetylcholine into the synaptic clef where the ACH(acetylcholine) travels down the sarcolemma into the T tubules into the SR which releases Calcium ions. The Calcium ions then attach to protein myosin which attaches to tripoponin a protein part of actin. The myosin contracts moving the actin and then more acetylcholine is produced so the myosin unhooks from the actin. These muscle

This is because once a contraction has started, the action potential has already fired, stimularing the muscle fibers. Once they

There are five steps in a reflex arc, which allows for impulse actions to occur called reflexes. The first step is when the receptor senses a stimulant. The next step occurs when the sensory neuron transmits nerves impulses to the spinal cord from the nerve and root. The third phase is when the sensory neuron goes through a neuronal junction with an interneuron; this occurs in the spinal cord. The fourth step is when the interneuron goes through neuronal junction with a motor neuron. Then the last step is when the motor neuron impulses through the spinal nerve and root to an effector structure. In summary, the receptor senses the action, then the sensory neuron transports the stimulus near the spinal cord, then the interneuron spreads the urge