A patient has tachycardia. Would you recommend a drug that prolongsor shortens the plateau of cardiac muscle cell action potentials?

The force of contraction can be changed by: can choose more than on e Group of answer choices - muscarinic ACh receptors.  Activation of the receptors leads to decreased Ca2+ entry and increased K+ entry in ventricles.     - Beta2 adrenergic receptors.  Increasing cAMP leads to increases in PKA, which increases sarcoplasmic calcium by opening VG Ca+ channels for a longer time, opening SR Ca2+ channels, and increasing the rate of Ca2+ removed by SERCA pumps.   - Beta1 adrenergic receptors.  Increasing cAMP leads to increases in PKA, which increases sarcoplasmic calcium by opening VG Ca+ channels for a longer time, opening SR Ca2+ channels, and increasing the rate of Ca2+ removed by SERCA pumps.   - Not by the parasympathetic NS. (at least, not the ventricles).

Hypertension increases afterload for the heart which in turn   a-decreases Stroke Volume b-increases Stroke Volume c-increases Cardiac Output d-increases Venous Return

The entry of calcium into a ventricular muscle cell helps to maintain depolarization of the membrane during the plateau phase of the action potential, but this calcium also performs what other function?

Detail action potential of myocardial conduction and contractile cells – see stages. Include all ion movement in your answer.

Describe the conditions at the sarcolemma of cardiac muscle cells at rest.

An ectopic pacemaker refers to the condition in which _____.   A the rate at which the SA node cells undergo spontaneous depolarization is abnormal   B "all of the heart cells function independently of one another such that the heart vibrates, but fails to pump blood"   C action potentials in the heart are initiated by a region other than the sinoatrial node   D the endothelial cells

The role of calcium currents in cardiac contractile cells is to .  The role of calcium currents in cardiac conductive cells is to .    Choose between: release neurotransmitter, bring the membrane potential to threshold, initiate action potential, prolong action potential, terminate action potential

Can you help me with questions 21 and 22

Cocaine use causes vasoconstriction. Is this likely to increase or decrease blood pressure, and why?