Sinoatrial Node Cells

question 75

Multiple Choice

Sinoatrial node cells:

• A) reach threshold only when action potentials generated by the AV node arrive through gap junctions.
• B) exhibit spontaneous depolarization that is speeded by activation of their cholinergic receptors.
• C) exhibit spontaneous depolarization that is speeded by activation of their beta-adrenergic receptors.
• D) exhibit a steep upstroke due to the presence of the same type of Na⁺ channels found in neuronal membranes.
• E) are in-between atrial muscle cells and cells of the bundle of His.

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