Question

give a detailed explanation to how the bicep muscles are able to contract IN ORDER AT the CELULAR and MYO FIBER levels when you go and sip a glass of coffee. these following ideas must be incorporated

• the fact that the resting-membrane potential is (-) charged in cells
• Depolarization as well as repolarization of the cells
• How the motor neuron's neural signal are sending to skeletal muscular cells
• adds the roles of SR andd T-tubule as well as thin and thicker filaments, cross-bridge, Calcium ions, power-stroke, muscle contraction's ATP

Answer 1

Movement often requires the contraction of a skeletal muscle. Contraction of the biceps muscle, attached to the scapula and radius, will raise the forearm, which aids you to sip a glass of coffee Muscle contraction begins when the nervous system generates a signal.the signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron, when the impulse reaches the neuromuscular junction a chemical message is released by the motor neuron a neurotransmitter called acetylcholine, binds to receptors on the outside of the muscle fiber that starts a chemical reaction within the muscle. Steps involved are as follows.

Acetylcholine Is Released and Binds to Receptors on the Muscle Membrane.

When acetylcholine reaches receptors on the membranes of muscle fibers, it open channels allow an influx of sodium ions into the cytoplasm of the muscle fiber, the influx of sodium ions changes the resting membrane potential making it less negative or more positive because of which deplorization occurs, this is followed by repolarization where the potassium moves out of the cell.
Depolarisation is spread through muscle fibers, via the T-tubules, depolarization causes the sarcoplasmic reticulum to release stores of calcium ions

Calcium binds to troponin, which causes tropomyosin to move this is turn gets myosin head to be exposed, the thin filament or actin and the thicker filament or myosin forms a cross bridge

Crossbridge formation causes myosin to release energy in the form of ATP, the shape changes, myosin head pivots pulling the actin filament towards the center, this movement is called the power stroke as it is in this step that force is produced, as the actin is pulled towards M line, the sarcomers shortens and the muscle contracts.