Muscle Phsyiology Essay examples

3. Considering your answers to Questions 1 and 2, why did activity in Annie’s motor nerves produce a skeletal muscle response that fatigued during repetitive stimulation?

The reason that Jim's muscles are feeling the burning sensation is because they are experiencing sensory info from his nervous system. This feeling is due to the increase of activity and fatigue occurring because he over exerted his body. Also his body has been using his glycogen within the cells which make lactic acid which causes the burn Jim is experiencing.

contraction, and this reduction in tension production is the cause of the loss of strength. Her muscles are actually

As the stimulus strengthens, action potentials are conducted at a greater speed, resulting in more tension and thus more force produced by the muscle. Wave summation occurs when a multitude of motor neuron signals are combined and increase to create greater muscle tension. As the stimulus strengthens the peak contractile force increases because the preceding twitch hasn't ended and is thus added to the new twitch - this building of tension increases the peak contractile force as stimulus

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.

It is important to understand muscle fatigue because it affects all people and plays a major roll for people whose lives revolve around physical activity. The purpose of this experiment was to determine how muscle fatigue affects the overall muscle performance of an individual and to gain insight on the effects muscle fatigue has on reaction time as well as fine motor skills. We hypothesized if muscle fatigue increases by increasing the number of muscle contractions in a certain period of time then the reaction time of the muscles will also increase because the muscles are not receiving enough oxygen to perform optimally. We also hypothesized that if the number of muscle contractions increases then the muscle's fine motor skills will decrease because the muscles are not able to get enough oxygen to

life and wanted us to help her feel better. Although Barbara was an avid golfer

A second reason is that by having a longer refractory period for cardiac muscle than skeletal muscle, it prevents tetanus in cardiac muscle. This is important because it is required for the ventricles to undergo contraction and relaxation completely for each beat to pump blood. Activity 2: Examining the Effect of Vagus Nerve Stimulation Results: Briefly describe what happened when you electrically stimulated the vagus nerve. (2 marks) RESULT: Upon stimulation of the vagus nerve at 50 stimuli/sec for 20 seconds being applied to the heart indirectly, I noticed the number of beats/ minute decrease slowly until after around 15 seconds the heart stopped beating.

Simply put, if muscle protein synthesis is not taking place, the muscles are breaking down.

In contrast to in clinical settings, in research settings it is possible to easily assess the absolute contraction speed and velocity of the stretch reflex using

Contrary to what was long thought, muscle fatigue is not due to the accumulation of lactate in

As the intervals were reduced the twitches got closer together. Each curve, which represents a response to the stimuli, got closer until they finally became one. This represents summation which is when the muscle is unable to completely relax before the next stimulus occurs. As a result, individual twitches begin to combine, and the contraction becomes sustained.

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

Exercise 2: Skeletal Muscle Physiology: Activity 3: The Effect of Stimulus Frequency on Skeletal Muscle Contraction Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. During a single twitch of a skeletal muscle You correctly answered: b. maximal force is never achieved. 2. When a skeletal muscle is repetitively stimulated, twitches can overlap each other and result in a stronger muscle contraction than a stand-alone twitch. This phenomenon is known as You correctly answered: c. wave summation. 3. Wave summation is achieved by You correctly answered: a. increasing the stimulus frequency (the rate of stimulus delivery to the muscle). 4. Wave summation increases the force produced in the muscle.

When a muscle exercises, it constantly contracts and relaxes, using energy in the form of ATP to do so. When intensive exercise is conducted (e.g. performing exercise at peak performance), there may be an insufficient amount of oxygen present in the muscles, resulting in the cells performing anaerobic respiration to produce energy. Anaerobic respiration produces much less energy than anaerobic respiration, though does so without the presence of oxygen. Performing anaerobic respiration results in the creation of a toxic substance in the muscles known as lactic acid. The build up of lactic acid in the muscles and the reduction in energy production are the main two causes of muscle fatigue.