The stimulus is measured in volts, and its role is to cause depolarization of the muscle…
A greater stimulus is required because voltage-gated K+ channels that oppose depolarization are open during this…
3. Explain what is happening in regards to sodium and potassium in a neuron at (see figure 7.10)…
-Increasing extracellular K+ reduces the net diffusion through the leak channels because if there are an increased amount of K+ ions outside of the cell, the amount coming from the leak channels needs to decrease so it can be balanced.…
3. Increasing frequency of stimulation to the trigger zone: DOES NOT increase the production of action potentials.…
What will happen to the resting membrane potential if the extracellular K+ concentration is increase? Less negative…
F. David has lost blood volume, resulting in a drop in blood pressure. His automatic nervous system countered the dropping blood pressure by stimulated vasoconstriction. How does…
A greater stimulus is required because voltage-gated K+ channels that oppose depolarization are open during this time. Why is the action potential recorded by the second recording electrode (R2) delayed relative to the action potential recorded by the first recording electrode (R1)? The action potential had to propagate from R1 to R2.…
17. The sodium-potassium pump in the neuron cell membrane uses the energy of ATP to pump Na+ out of the cell and, at the same time to pump K+ in.…
“(3) Specific enzymes that drive active pumps that promote concentration of certain ions, particularly potassium (K+), within the cell while keeping concentrations of other ions, for example sodium (Na+), below concentrations found in the extracellular environment…” (McCance &Huether, pg. 12).…
Smooth muscle contractions are affected by calcium and potassium ions. Calcium ion influx into the smooth muscle cell initiates a contraction. Potassium ion concentration in the extracellular medium affects the resting membrane potential of the cell, bringing it closer to or farther away from its threshold voltage. Neurotransmitters affect different types of smooth muscle differently, depending on the association of the smooth muscle with excitable cells. In general, acetylcholine increases the muscle cell’s permeability to calcium, while epinephrine decreases the cell’s permeability to calcium.…
Primary disturbances in magnesium balance, especially magnesium depletion, create auxiliary potassium depletion. Magnesium hinders potassium, which then magnesium pushes the potassium out the cells through renal excretion causing hypokalemia. In order for the cell to keep up the typically high intracellular grouping of potassium the expansion in the membrane permeability to potassium as well as the restraint of Na+-K-ATPase needs to take place.…
The rate of active transport of sodium potassium pumps will decrease dramatically due to the lessened concentration of pumps.…
a. The opening of voltage-gated K+ channels cause the membrane to repolarize. b. Does K+ move into or out of the cell? Out of c. If the membrane potential becomes more negative than –70 mV, this is called hyperpolarization. d. This potential is caused by what characteristic of K+ permeability?…
a. What acts as a chemical force that pushes K+ out of the cell? ___________…