Describe the role of differential electrical charge across the cell membrane in both non-excitable and excitable cells. Include in your description terms like equilibrium potential, hyperpolarization, depolarization, and the sodium-potassium pump. For excitable, think in terms of both neuron and muscle.

Question 4 Place the following events in order of their occurrence. 1. membrane repolarizes 2. K+ voltage gated channels open 3. Na+ voltage gated channels close 4. threshold is reached 5. membrane depolarizes 6. Na+/K+ pump reestablishes resting potential 7. Na+ moves through non-gated channels 8. Na+ voltage gated channels open 9. hyperpolarization then closure of K+ gates 10. membrane depolarizes to peak O 7.5.4.8.10.3.2.1.9.6 O 5.9.4.3.10.1.2.8.6.7. O 3.7.9.5.10.6.4.2.1.8 O9.6.8.10.2.5.7.1.3.4.9. « Previous

If: membrane potential=-70mV, ENa=+60mV, and Ex=-90mV, consider which directions Na+ and K+ will leak across the membrane. If both ions are crossing the membrane, what is the most important factor in determining whether membrane potential will become more positive or more negative?

If the resting membrane potential of a cell was +70 mV, the ELECTRICAL driving force on sodium would be:  Group of answer choices into the neuron out of the neuron balanced

Consider the brain and spinal neurons. If you bathed a resting neuron with an excess of potassium ions (for example, more than 40 times higher than normal), what would be the effect on resting membrane potential?

Physiology question

Answer questions 1-5 about a cell that has: [ECF) of Na" = 142 mM, and K* = 4.6 mM (ICF] af Na* = 9 mM and K* = 155 mM The membrane has eight (8) times more K leak channels than Na*leak channels. 1. What is the resting membrane potential for this cell? 2. What would the resting membrane potential be if a drug was administered that blacked Na" leak channels? 3. To what would the membrane potential change if a stimulus apened an amount of Na* gated channels that was 500 times greater than the number af Na* leak channels? 4. What would be the direction of the Na* electrochemical gradient if the membrane potential were 80 mV? Into cell Out of cell 5. How much mare permeable would the above cell be to patassium than sodium if the measured resting membrane potential was -68 mv?

Question: Suggest two reasons why people had the drug injected into the cerebrospinal fluid (lines 12–13) rather than taking a pill containing the drug.

a)The distribution of sodium ions across the cell membrane of a neuron is 20 mmol/L inside the cell and 200 mmol/L outside the cell. When the system reaches equilibrium, the concentration of sodium ions will be identical on both sides of the cell membrane. What is the standard Gibbs energy difference in the system? Assume the system is at body temperature (37 °C). b)What is the Gibbs energy difference across the membrane in the initial state (prior to reaching equilibrium)?

Myasthenia gravis is a disease that leads to a marked decrease in the number of acetylcholine (Ach) receptors at the neuromuscular junction.  As a result, suppose only about 200 (instead of 2000) Ach receptor-channels are opened by each quantum of Ach.  The Ach-gated channels that survive operate normally and each cause a depolarization of about 0.25 x 10-3 mV when open.  The function of the presynaptic terminal is normal and an action potential will cause the release of 100 quanta of neurotransmitter.  Part a.) For a patient with myasthenia gravis, what would be the size (in mV) of a miniature excitatory post-synaptic potential (or that associated with one quantum of Ach)? a.) 0.05 mv b.) 0.25x10-4 mv c.) 0.25x10-3 mv d.) 0.5x10-3 mv e.) 0.5 mv   Part b.) For a patient with myasthenia gravis, what would be the size (in mV) of the full excitatory post synaptic potential consequent to the entry of an action potential into the presynaptic terminal of the neuromuscular junction? a.) 70 mv…