Discuss how a change in na or k conductance would affect the resting membrane potential

Inasmuch as brain fluid is incompressible, both the extracted and re-injected or delivered fluid volumes should be equivalent, except for any fluid lost during the ion-concentration adjustment. In an optimum system, a closed-loop feedback system would include a system that measures ion concentration or other electrical characteristic and uses this information to control fluid extraction, delivery or ion content so as to achieve the optimum electrical potential difference between the inside and outside of brain cells, imbalances of which might cause epilepsy or other neurological disorders.

The method may be focused on neurological disorders, and may also comprise multiple additional steps. Measurement of the net current flowing across the membrane of a neuron can be made with a. The slope of the end-systolic line ESL increases increased inotropy and the slope of the end-diastolic line EDL decreases increased lusitropy.

Describe the role of left ventricular diastolic function in cardiac physiology Discuss the influences of ion regulation in myocardial contraction and relaxation Explain components of neurohumoral regulation of left ventricular function Left ventricular diastolic function plays an important role in cardiac physiology.

Parham, MD, Ali A. Increased collagen cross-linking within the extracellular matrix induced by impaired glucose tolerance has been associated with an increase in left ventricular diastolic stiffness and higher end-diastolic pressure when volume loading occurs.

Calcium-channel blockers such as verapamil and diltiazem affect the plateau phase phase 2 of the action potential. Journal of Physiology 3: Constant terms in the Nernst equation.

The resting membrane potential The Nernst equation accurately predicts the membrane potential if there is a single permeable. BMC Neuroscience 5 did not produce any further changes in the cone resting membrane potential 7 mV using the junction potential calculator.

The equilibrium potential for an ion is the electrical potential difference across the membrane that would have to be present to stop all net movement of that ion across the membrane through its conductive pathways. Functional control of many or all body functions can be lost and further, in general permanent brain damage results from each generalized epileptic attack.

The Ionic Basis for the Action Potential

Resting has made your life a lot easier with these easy-to-access. There are receptor sites available to bind with transmitter substance. During the initial phase of the action potential, potassium conductance, gK has been rising.

Passive properties are independent of the effects of viscoelasticity that are prominent in other diastolic phases. Left atrial pressure is primarily determined by left atrial and pulmonary vein volume and compliance, whereas left ventricular pressure is chiefly affected by the biochemical events at the myofibrillar level and the viscoelastic properties of the myocardium.

We also briefly describe the mechanism by which the resting potential can be perturbed, giving rise to transient electrical signals such as the action potential. This patent application also claims priority to U. Atrial myocytes, ventricular myocytes and Purkinje cells are examples of non-pacemaker action potentials in the heart.

Provisional Patent Application Serial No. The ion concentration of the fluid of the brain may be modified by delivering fluid to the brain, the ion concentration of the delivered fluid being such as to cause the ion concentration in the brain to be modified.

The efflux of potassium. The period from closure of the mitral valve point B to opening of the aortic valve point C represents isovolumic contraction. It is generally accepted that the passive filling characteristics of the left ventricle are most purely reflected during the diastasis and atrial contraction phases of diastole.

Neal Woodbury One of the most confusing aspect of membrane potential calculations. Next Section Abstract Left ventricular diastolic function plays an important role in cardiac physiology.


Suppose you apply electrodes to the middle of a squid giant axon and apply a supra-threshold stimulus. It is this interval, which at normal heart rates is ms long, that is shortened by increases in heart rate. Ionic basis of the action potential. This shows that a. In this case that is in the same direction as the chemical gradient, but not in the same direction as the electrical gradient.

The value of the chemical drive in terms of a vector is equal to the value of the electrical drive.

Problem Set 7

So I need your help. A change in the potassium conductance would have a greater effect on the resting membrane potential than a change in sodium would. Persistent outflow of K +, now exceeding Ca 2+ inflow, brings TMP back towards resting potential of −90 mV to prepare the cell for a new cycle of depolarization.

Normal transmembrane ionic concentration gradients are restored by returning Na + and Ca 2+ ions to the extracellular environment, and K.

During resting potential, the inside of the axon is negative GRADED POTENTIAL ACTION POTENTIAL Action potential is a fleeting reversal of the membrane potential, caused by changes in permeability of the plasma membrane of neuron to potassium and sodium ions causing an electrical impulse to be transmitted along the axon.

Discuss how a change in Na+ or K+ conductance would affect the resting membrane potential The resting membrane potential depends on the intracellular. Antiarrhythmic drugs that affect the movement of these ions are used to alter cardiac action potentials in order to prevent or stop arrhythmias.

In non-nodal tissue, sodium-channel blockers decrease the fast inward movement of Na +, thereby decreasing the slope of phase 0 and the magnitude of depolarization.

A change in the potassium conductance would have a greater effect on the resting membrane potential than a change in sodium would.

Discuss how a change in na or k conductance would affect the resting membrane potential
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