Muscle Memory Essay

Action potentials can occur more frequently as long there is a continued source of stimulation, as long as the relative refractory period has been reached, which in experiment 2 the refractory period was complete.

If the frequency of action potentials in the excitatory presynaptic cell increases than the number of action potentials in the postsynaptic cell will increase as well. This is due to temporal summation of EPSP at very frequent times. This causes the postsynaptic cell to produce many action potential in succession.

Skeletal muscle is the organ responsible for movements in the locomotor system. Skeletal muscle is under voluntary control, unlike smooth and cardiac muscle. Nerve impulse is the source of stimulation for the skeletal muscle activity, because skeletal muscle has no intrinsic activity because of the lack of ion channels that are responsible for the depolarization of membrane (Philip M., 2006). Muscle contraction results from the interaction of the filamentous proteins, actin and myosin. It starts when an action potential travels to the skeletal muscle along the motor neuron, where the neuromuscular junction releases acetylcholine that binds to the sarcolemme receptor, which cause Na+ to enter the muscle fiber and generate another action potential inside the muscle

The amplitude of the muscle contraction increased as the voltage increased until a threshold was met.

Voltage-gated calcium channels function in many ways, one of the most important of which is its role in stimulating the release of vesicles containing the neurotransmitter acetylcholine into the neuromuscular junction. As an action potential reaches the terminus of the neuron, voltage-gated calcium channels are opened causing an influx of calcium into the presynaptic terminal. Acetylcholine filled vesicles, in response to the increase in calcium concentration, fuse to the plasma membrane releasing acetylcholine into the neuromuscular junction. When released in sufficient quantities at neuromuscular junctions acetylcholine binds to post synaptic receptors on the muscle cells and causes contraction of the muscle. If this delicate system

2.2). These axonal regions contain high densities of voltage gated sodium (Na+) channels, while potassium channels are restricted in the juxtaparanodal region (Kaplan et al., 1997; Peles and Salzer, 2000; Rasband and Shrager, 2000; Kaplan et al., 2001). The isolation properties and the segmental formation of myelin, leading to the clustering of the ion channels, enable the saltatory conduction of electrical nerve pulses. Pulses are jumping from node to node, instead of progressing slowly along the whole axonal surface as along unmyelinated axons (Huxley and Stampfli, 1949). As a result the conduction velocity along myelinated axons is 10 to 100-fold faster as compared to unmyelinated ones (Waxman, 1980), while the energy consumption is reduced (Waxman, 1977; Hartline and Colman,

The compound action potential adds up all the action potentials that each individual neuron experiences in the sciatic nerve. Different stimulus amplitudes cause different neurons to fire an action potential; this is due to the fact that each neuron has a different threshold potential, or the minimum voltage the neuron needs to fire an action potential. The individual neuron action potential is an ‘all-or-nothing’ event, but the CAP, as a summation of different individual neurons, is not. The CAP amplitude will increase with larger stimulus potentials because more neurons with higher individual thresholds will be recruited. For this frog sciatic nerve, there are three fiber types, A, B, and C. A fibers are further divided, in the order of decreasing diameter, into α, β, γ, and δ fibers. There is an inverse relationship between the diameter of the nerve fiber and the threshold potential: the larger the diameter, the lower the threshold. Thus, as the largest fibers, the Aα neurons will be the first to be stimulated at a low stimulus potential, and the Aδ neuron fibers will be the last to be recruited. Because the sciatic nerve is mostly composed of A fibers, the recruitment of A-subtype nerve fibers are more readily distinguishable from the data. The minimum potential required to stimulate the Aα fibers was between 75 mV and 80 mV. Once the stimulus potential reached 90 mV, Aβ neurons were recruited and contributed to the increase in amplitude of the CAP. At a stimulus

If you are conscious about your muscles, then you may be noticed the role of "muscle memory" in your life. Once you have enhanced your muscles and trained them to grow, your muscles grow again following a cutting phase or a break because any valuable reason. Every muscle in our body is smart. A muscle that has reached a certain level may find its way back easily.

The baseline relationship was approximately 23 grams. The voltage magnitude gradually increased and the first muscle twitch occurred at 0.5 volts. This voltage produced a tension of 56.66 grams of force. It was decided that 0.5 volts would be the threshold voltage. The experiment proceeded with increasing the stimulus by 0.025 volts for every trial. The greatest increase of muscle tension occurred on the third trial, where tension jumped from 57.65 grams to 86.72 grams. Stimulus input continued and the trend saw a gradual increase in force strength, until reaching the eighth trial where tension strength was approximately 117.67 grams. Out of consideration for data accuracy, three more trials were done. Here, the tension stopped increasing

Experiments B and C were used to calculate the motor nerve conduction velocities of the Ulnar and median nerves respectively. At each stimulating site; the latency, amplitude and duration of the CMAP were measured. Latency is the time from the stimulus to the initial negative deflection from the baseline (Kandel, Schwartz & Jessell, 2013). Latency represents the nerve conduction time, the time delay across the neuromuscular junction and the depolarization time across the muscle

The more stimuli per second, the greater the force generated by the muscle due to a

As it is an extracellular recording, the sign of the voltage trace of the action potential is reversed. Besides, the amplitude is much smaller than for intracellular recordings. Then, we used Matlab to extract the waveforms from the first day and the waveforms from the second day from these extracellular data. The total number of observations for the first and second day’s data are 120407 and 80397, separately.

action causes the charge in the neuron to change from the negative passive to the positive firing state (Feldman, 2009, p.63). The velocity at which the neuron fires the message or impulse depends on the concentration level of the stimulus. As explained in the text, “when a nerve impulse comes to the end of the axon and reaches a terminal button, a chemical courier called a neurotransmitter is released (Feldman, 2009, p.65). For successful communication to happen between the neurotransmitter and the neuron, they must fit together perfectly. When a miscommunication happens, the chemical message is either excitatory or inhibitory.

When a neuron depolarizes from its resting potential to its threshold potential, positively charged sodium ions rush down to the end of the neuron in the form of an action potential. Multiply the process by one-hundred billion, and you get the human brain. All these parts interact in a fast paced manner. Despite this, the

It is the electrical events that are conducted along the entire length of the nerve cell's axon. At threshold potential, special sodium channels called voltage-gated channels are triggered to rapidly open,at that time, so too are the potassium voltage gated channels triggered to open (they open very slowly). When opened this allows a large amount of sodium ions to rapidly enter the cell down their concentration gradients, this results in a rapid depolarisation. Once a key maximum potential is reached usually about plus 30 millivolts the voltage gated sodium channels close. The depolarisation stops. Focusing on the potassium channels now, by the time the action potential peak is reached these channels are fully opened. And now a large amount of potassium ions move out of the cell down their concentration gradient. The removal of positive charges results in the membrane potential becoming more negative known as repolarisation. The cell nown returns to its resting values the potassium channels are triggered to close but they close slowly resulting in hyperpolarization. Finally the potassium voltage gated channels close and hyperpolarization stops and the membrane potential returns to rest. This all happens within two