PhysioEx Exercise 3: Neurophysiology of Nerve Impulses is an interactive laboratory simulation that allows students to explore the physiological processes involved in the transmission of nerve impulses. The second activity of this exercise focuses on the role of ion channels in the generation and propagation of action potentials.
In this activity, students are first introduced to the concept of action potentials, which are electrical signals that are generated by neurons in response to stimuli. Action potentials are generated when the membrane potential of a neuron becomes depolarized, meaning that the voltage across the membrane becomes more positive. This depolarization is caused by the flow of ions across the membrane through ion channels, which are special proteins that are embedded in the membrane.
There are two main types of ion channels: voltage-gated ion channels and ligand-gated ion channels. Voltage-gated ion channels are sensitive to changes in the membrane potential, and they open or close in response to these changes. Ligand-gated ion channels are activated by specific molecules, called ligands, which bind to the channel and cause it to open.
In the second activity of PhysioEx Exercise 3, students are asked to investigate the role of ion channels in the generation and propagation of action potentials. To do this, they use a simulated neuron and apply various stimuli to it to see how the neuron responds. By adjusting the stimuli and observing the resulting changes in the neuron's membrane potential, students can learn about the different types of ion channels and how they contribute to the generation and propagation of action potentials.
One of the key concepts that students learn in this activity is the importance of the ionic gradient in the generation and propagation of action potentials. The ionic gradient is the difference in concentration of ions on either side of the membrane, and it plays a critical role in the movement of ions across the membrane. When the ionic gradient is disturbed, it can lead to changes in the membrane potential, which can in turn trigger the opening or closing of ion channels.
Overall, the second activity of PhysioEx Exercise 3 is an important learning opportunity for students interested in understanding the physiological processes involved in the transmission of nerve impulses. By interacting with a simulated neuron and applying various stimuli, students can gain a deeper understanding of the role of ion channels in the generation and propagation of action potentials and the importance of the ionic gradient in this process.
Physio Ex Exercise 3 Activity 2
In the control, the amplitudes of the action potentials at R1 and R2 are the same. Are these results called treppe or wave summation? All of these answers are correct. The amplitude of the response was 40 mV for this modality. You correctly answered: all of the above. TTX alters the resting membrane potential of all neurons in the lips d. Explain how each is achieved in vivo. What passive channels are likely found in the membrane of the olfactory receptor, in the membrane of the Pacinian corpuscle, and in the membrane of the free nerve ending? Which of the following has the most negative voltage? Which of the following has the most negative voltage? You correctly answered: Yes, the second twitch generated more muscle force.
Your answer: The stimulus modality that induced the largest amplitude receptor potential in the olfactory receptors was high-intensity chemical. When voltage-gated Na+ channels between R1 and R2 are blocked with TTX, an action potential is still recorded at R1 because a. It is harder to generate a second action potential soon after the first action potential because a. Another way to increase the force produced by a muscle is to You correctly answered: increase the number of activated motor units. In between these modalities, moderate-intensity pressure would induce the largest response, so it compared accurately with my predictions. Was there any change in the force generated by the muscle during the second stimulated twitch? Thus, with a blow to the eye, one "sees stars. Does the free nerve ending likely have this isoamylacetate receptor protein? There will be a limit to this increase.
You correctly answered: a change to -60 mV. Review Sheet Results A very intense stimulus can sometimes stimulate sensory neurons that have evolved for a different modality. Your answer: Neither the Pacinian corpuscle nor the free nerve ending are likely to have the isoamylacetate receptor because neither of them responded to the chemical stimuli exposed to them, which is the adequate stimuli for olfactory receptors. I predicted that the moderate-intensity pressure would induce the largest amplitude receptor potential, but that was in reference to the options given which included chemical, light, and heat stimuli as well, but not the option of a high-intensity pressure option. The membrane has open K+ channels, and changing extracellular K+ concentration results in a change in membrane potential. Your answer: As the stimulus frequency increases, the muscle force generated by each successive stimulus will increase. If a nerve, rather than an axon, had been used in the lidocaine experiment, the responses recorded at R1 and R2 would be the sum of all the action potentials called a compound action potential.
You correctly answered: Yes, it is greater than the previous stimulations. Your answer: You must increase the frequency of the stimulus stimulus to both to reach. I predicted that the moderate-intensity chemical would induce the largest amplitude receptor potential, but that was in reference to the options given which included pressure, light, and heat stimuli as well, but not the option of a high-intensity chemical modality. Describe the force of contraction with each subsequent stimulus. How well did the results compare with your prediction? Changing the extracellular Na+ concentration does not significantly change the membrane potential. Your answer: By the term graded potential, it is meant that they are brief, localized changes to the membrane potential that can be either depolarizing or hyperpolarizing.
Are these results called treppe or wave summation? You correctly answered: As the stimulus frequency increased, the muscle tension generated by each successive stimulus also increased, and a limiting maximum value was observed. There are voltage-gated Na+ channels all along the axon. Your answer: These are called wave summation, because there is a noted increase in frequency, which resulted in an increased in the force produced by the entire muscle. Post-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. A glucose standard curve is a tool used to measure the FPG levels taken from several patients to diagnose the presence or absence of diabetes.
Your answer: moderate-intensity chemical. An action potential is a large, all-or-none change in membrane potential. You correctly answered: a change to -50 mV. All of these make it harder to generate a second action potential With a prolonged stimulus that is just above more depolarized than threshold, you would expect to get additional action potentials when the membrane has complete a. What do your results suggest about the number or state open or closed of Na+ channels in the resting membrane of a neuron? The generation of an action potential uses voltage-gated Na+ channels. How well did the results compare with your prediction? This phenomenon is known as You correctly answered: wave summation. .
You correctly answered: application of higher voltages to the whole muscle. The action potential is an all-or-none event. The test only tells us this, so I would need more information before I can confirm that these patients have either type of diabetes. PhysioEx Lab Report Exercise 3: Neurophysiology of Nerve Impulses Activity 2: Receptor Potential Name: Karime Castillo Date: 29 May 2020 Session ID: session-8522d165-8156-9e52-5f40-c0d99e61ede Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. Patients 3 and 5 are in the diabetic range but I can't say that these patients have these specific types of diabetes since both patients 3 and 5 have high plasma glucose results. An action potential is generated when the membrane potential reaches threshold. PhysioEx Lab Report Exercise 2: Skeletal Muscle Physiology Activity 3: The Effect of Stimulus Frequency on Skeletal Muscle Contraction Name: Kaley Faucher Date: 15 September 2020 Session ID: session-7ccf421d-b4b3-33ce-637e-1d856a1de Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly.
You correctly answered: Light-transducing proteins are not present in the Pacinian corpuscle. How was each achieved in the experiment? Would the response at R2 after lidocaine application necessarily be zero? This phenomenon is known as 3 Review Sheet Results You correctly answered: wave summation. If not, how did you achieve an active force of 5? Will there be a limit to this response? Which of the following modalities will induce the largest amplitude receptor potential in the olfactory receptor? Which of the following is not one of the ways that the body can increase the force produced by a skeletal muscle? Your answer: No, the voltage remained the same through my predications. You correctly answered: all of the above. Your answer: The passive channels that are likely found in the membrane of the olfactory receptor, Pacinian corpuscle, and in the membrane of the free nerve ending are passive ligand-gated potassium channels. Does the Pacinian corpuscle likely have this isoamylacetate receptor protein? How well did the results compare with your prediction? In between these modalities, moderate-intensity pressure would induce the largest response, so it compared accurately with my predictions. The stimulus had an increased frequency at which it stimulated the muscle fiber.
You correctly answered: The sensory end of this nerve is less specialized. All of these are reasonable explanations. Eating puffer fish can cause numbness of the lips, probably because a. You correctly answered: No. You would never get additional action potentials at this intensity.
