Your studies of the neuromuscular junction reveal that the excitatory neurotransmitter opens a channel permeable to all three cations. Calculate the equilibrium potential for each cation. In which direction will each cation move when the channel is open? Does movement of ions promote muscle depolarization? Explain your answer.
What will be an ideal response?
ENa+= 61 × log 450/50 = 58 mV. EK+= 61 × log 20/420 = -81 mV.
EMg++= 61 × log 60/10 = 47 mV.
Sodium and magnesium will enter the cell, potassium will exit. Exit of potassium opposes depolarization, but
presumably there will be a net gain in intracellular positive charge sufficient to depolarize the cell.
You might also like to view...
The atrioventricular (AV) node is located in the
A. floor of the left atrium. B. floor of the right atrium. C. roof of the left ventricle. D. back wall of the right ventricle. E. back wall of the left ventricle.
Peristalsis within the intestines is regulated by the ________ nervous system.
A. parasympathetic B. somatic C. sympathetic D. enteric
Interferons are released by some macrophages and lymphocytes, but also by cells carrying what pathogen?
A) parasites B) viruses C) bacteria D) prions E) spirochetes
Hypertension is often treated with drugs that increase total peripheral resistance
Indicate whether the statement is true or false.