1. a Patient Is Admitted for Electroconvulsive Treatment (Ect). the Physician Orders the Neuromuscular Blocking Agent Metocurine Iodide (Metubine) to Reduce Trauma by Relaxing Skeletal Muscles. Explain the Process of
A patient is admitted for electroconvulsive treatment (ECT). The physician orders the neuromuscular blocking agent metocurine iodide (Metubine) to reduce trauma by relaxing skeletal muscles. Explain the process of muscle contraction and how a neuromuscular blocking agent, such as Metubine, would interfere with muscle contraction.
In order to understand how a neuromuscular blocking agent works one must first understand the process of muscle contraction and what has to take place in order for us to be able to move our muscles.
To create a muscle contraction your brain sends a message (nerve impulse) to your muscles via axon extensions. The end of this axon forms a union with a single muscle fiber; this union is called the neuromuscular junction. The axon terminal and the muscle fiber don’t actually touch at this junction; they are attached by a space called the synaptic cleft. (Marieb and Hoehn, 2007) Inside the axons terminal there are small sacs containing the neurotransmitter ACh. When the message reaches the end of the axon it opens Calcium channels and Calcium moves into the extracellular space. Once the Calcium is in this space it causes the ACh filled sacs to fuse with the axons membrane and ACh is released into the synaptic cleft. (Marieb and Hoehn, 2007) This ACh drifts across the cleft and into ACh receptors in the sarcolemma of the muscle fiber. After the sarcolemma receives the ACh, ion channels in the ACh receptors are opened and Sodium and Potassium both pass through them. Sodium then triggers action potential that travels across the sarcolemma and into the T Tubules. Once the AP is in the T tubules it is sensed by receptors and causes the sarcoplasmic reticulum to release Calcium into the muscle fibers cytosol. (Marieb and Hoehn, 2007) This Calcium attaches to the Troponin complex located on the thin filament. When the Calcium attaches it changes the shape of the Troponin complex and the Tropomyosin proteins can no longer block the actin
In order to understand how a neuromuscular blocking agent works one must first understand the process of muscle contraction and what has to take place in order for us to be able to move our muscles.
To create a muscle contraction your brain sends a message (nerve impulse) to your muscles via axon extensions. The end of this axon forms a union with a single muscle fiber; this union is called the neuromuscular junction. The axon terminal and the muscle fiber don’t actually touch at this junction; they are attached by a space called the synaptic cleft. (Marieb and Hoehn, 2007) Inside the axons terminal there are small sacs containing the neurotransmitter ACh. When the message reaches the end of the axon it opens Calcium channels and Calcium moves into the extracellular space. Once the Calcium is in this space it causes the ACh filled sacs to fuse with the axons membrane and ACh is released into the synaptic cleft. (Marieb and Hoehn, 2007) This ACh drifts across the cleft and into ACh receptors in the sarcolemma of the muscle fiber. After the sarcolemma receives the ACh, ion channels in the ACh receptors are opened and Sodium and Potassium both pass through them. Sodium then triggers action potential that travels across the sarcolemma and into the T Tubules. Once the AP is in the T tubules it is sensed by receptors and causes the sarcoplasmic reticulum to release Calcium into the muscle fibers cytosol. (Marieb and Hoehn, 2007) This Calcium attaches to the Troponin complex located on the thin filament. When the Calcium attaches it changes the shape of the Troponin complex and the Tropomyosin proteins can no longer block the actin
Cited: Marieb, E. N. and Hoehn, K. (2007). Human Anatomy and Physiology (Seventh Edition). Pearson Benjamin Cummings: San Francisco.