The rising phase of an action potential is mostly due to PDF

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The rising phase of an action potential is mostly due to: a. inward flux of Na+ b. inward flux of K+ c. inward flux of Na+ and K+ d. outward flux of Na+ e. the Na/K ATPase a. inward flux of Na+ The equilibrium potential for an ion is defined as the potential at which: Select one: a. the tendency for the ion to move down its concentration gradient is exactly counterbalanced by its tendency to move down its electrical gradient b. there are equal numbers of ions inside and outside the membrane c. the number of positively charged ions leaving the cell exactly equals the number of negatively charged ions entering the cell d. Na+, K+ and Cl- ions are in equilibrium across the membrane e. the Na+/K+ co-transporter exactly counterbalances the movement of ions through ion channels in the membrane a. the tendency for the ion to move down its concentration gradient is exactly counterbalanced by its Calcium ions contribute little to the resting membrane potential in most cells despite the fact that they have a large transmembrane concentration gradient and hence a very positive equilibrium potential. Why? Select one: a. because Ca++ ions are too insoluble to contribute to resting potential b. because Ca++ ions are too large to pass through proteinaceous ion channels c. because there are no Ca ion channels in normal cells d. because Ca ion channels are rarely open at resting membrane potential e. because Ca++ ions are so toxic to the cell d. because Ca ion channels are rarely open at resting membrane potential Which two constants describe the rate of change of membrane response to a signal and how far the signal spreads along a nerve fibre? Select one: a. The Faraday Constant, the Gas Constant b. The Faraday Constant, the Space Constant c. The Space Constant, the Gas Constant d. The Time Constant and the Space Constant e. The Time Constant and the Faraday Constant d. The Time Constant and the Space Constant...