Physioex 9.0 Ex 2 Activity 4: Tetanus in Isolated Skeletal Muscle - Lab Report

Oxygen debt in the muscles is reached when oxygen levels are much lower than required during strenuous physical activity, causing lactate fermentation to occur in the cells leading to muscle fatigue. The results found in the experiment were the number of squeezes in the first trial for the dominant and non-dominant hands were significantly higher than the remaining ones. The results also showed as the trials continued, the number of muscle contractions decreased steadily which supported the hypothesis. However, there were some increased numbers for the dominant hand from trial 4 to 5 and trial 9 to 10. The non-dominant hand expressed similar unexpected results from trial 6 to 7 and trial 9 and 10. The reasons for these results might be due to the finger muscles being worked at the high intensity for a long period of time causing the muscles to consume higher amounts of oxygen thus producing more ATP production. This would cause the muscles to create more contractions towards the end of the trials. The unexpected results could also be caused by experimental errors such as faulty clothespins. The springs connecting the two ends of the clothespin was tight causing the number of contractions as the trials progressed having a more significant decrease. This is because the amount of energy required to open and close the clothespin would be higher, causing the lactate threshold to occur quicker. Due to this, the number of squeezes would decrease drastically as the trials progressed, in contrast to if the springs were normal. This would change the results by the difference between the trials not being evident therefore, not demonstrating the effects of muscle fatigue. Another factor that altered this experiment was the participant’s condition, Palmar Hyperhidrosis –excessive sweating on the palms – which

An increase in the strength of a muscle’s contraction is necessary to perform a task. Subsequently, the brain increases the number of simultaneously active motor units within the muscle by a process known as the motor unit recruitment. Physical muscle movement in humans involves movement of fibers which are hundreds of cylindrically shaped cells bound together by connective tissue. It is essential for individuals, mainly professionals who work to promote health, to understand the mechanisms in the body. Resting skeletal muscles in vivo exhibit a phenomenon known as tonus, a constant state of slight tension that serves to maintain the muscle by motor centers in the brain and spinal cord. However, muscle

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

The results in Figure 2. show that increasing the stimulus strength (V) from 0 to o.40V will result in an increase of Active Muscle force generated by the gastrocnemius muscle in the Buffo Marinus, confirming the hypothesis. The force generated plateaus when the stimulus is beyond o.40V.

Next with a stimulation duration of 50us, the stimulus amplitude should be set to the maximal tolerable stimulus intensity. With stimulus frequency of 2Hz, observe and record the leg movement, increase it by 5Hz but should not exceed 50Hz. With the electrodes connected to the analogy output channel and ground of the DAQ board. With the corresponding LabVIEW program, the frequency and amplitude (voltage) of the stimulation supplied to the leg can be controlled. With this the “sweet spot” of the lowest amplitude and best frequency to cause evoked movement can be found and recorded. Now the stimulation frequency should be set to 10Hz and the duration of stimulation pulse to 5ms or less. The range if leg movement changes can be observed as amplitude changes. Electrical stimulation in increments of 0.01V should be delivered and the minimal voltage required to generate muscle twitch should be recorded. The pulse duration should then be increased by durations of 10ms and the minimum voltage should be recorded this should be repeated for a variety of pulse

Introduction: According to the “Human Physiology Laboratory Manual “,BIOL 282 ,page 31 , the reason of performing this experiment is to learn how the muscle contraction occurs based on the molecular level and what kind of factors are involved .As a matter of fact, skeletal muscles contain a lot of nuclei because of the cell fusion while being developed and are made of cylindrical cells that have myofibrils. The myofibrils contain sarcomeres and the

The Purpose of this exercise is to understand how muscle twitch, contract and react to different activities.

To test the muscle strengths the subjects were required to use the one repetition maximum method for a variety of different exercises. The experiment consisted of the subjects rising from the chair without the use of their hands. During the trial reflective markers were

Current research suggests that trigger points are caused by a dysfunction in the nerves that signal the muscles to contract (Simons, Travell, & Simons 1999). When the neural activity becomes unsynchronized, it can cause muscles to contract without relaxing (Simons et al. 1999; Ge, Fernandez-de-las-Penas, & Yue 2011). This constant contraction results in a trigger point, which restricts blood flow to the taut muscle area and causes both localized and referred pain (Ge et al. 2011). Researchers theorize that DN interferes with the malfunctioning nerve signals and resets them to their normal function (Simons et al. 1999; Giamberardino, Affaitati, Fabrizio, & Costantini 2011).

Facilitation occurs when postsynaptic potentials evoked by a stimulus are increased when that stimulus closely follows a pervious stimulus. Five stimulus pulses were given at decreasing interpulse intervals. The data for this experimenet displays that when the interpulse interval changes from 10msec to 8 msec, the number of pulses needed to reach the maximum MAP increases rather than the expexted outcome. This is most likely due to movement of the muscle in the chamber, causing the recordings to be reading different areas of the muscle. Different neuromuscular junctions in the muscle require different amounts of Ach in order for muscle action potentials to reach threshold.

There are several different ways to measure the overall activity of skeletal muscles; one way deals with the electrical activity. During a contraction of skeletal muscles a significant amount of

A muscle is composed of multiple individual muscle fibers that are organized in a motor unit that is innervated by a single motor neuron. The motor neuron is responsible for propagating an action potential resulting in the muscle fibers in the motor unit contracting. An electromyography (EMG) is able to detect the depolarization of the muscle fibers, characterizing an action potential, and help quantify the number of active fibers and the magnitude of force. We hypothesize that the triceps will be activated more for movements involving supination with and without elbow extension than during reverse and regular curls as indicated by values from the EMG. We tested the hypothesis by connecting two surface-level electrodes to the triceps and

To fully understand the events taking place and the data collected, a brief but thorough review of muscles on a physiological level is needed. Muscles are responsible for producing force and motion in the both the external world and within the body. Locomotion of the body and its organs is achieved via the contraction of three types of muscles: skeletal muscle, cardiac muscle, and smooth muscle. Our lab focuses on the effects of stimulation of skeletal muscle and more specifically, the relationship between a motor neuron and muscle contraction.

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

Tetanus is also known as lockjaw, it is a very dangerous diseases because it locks your whole body. It is an infection ( muscle spasms ), it normally starts with your jaw and then starts progresses to your whole body. This disease can kill you in fact 10% of people get infected every year and die. Tetanus was well known to ancient people , it was made in 1884 by a man called Arthur Nicolaier who was doing an experiment on animals but it then went on to humans from the animals. In 1924 tetanus was induced by battle wounds during ww1.