What do nodal cells have that is similar to neurons?

What do nodal cells have that is similar to neurons?

• A. Na+/K+ pumps and voltage-gated channels.
• B. Mitochondria producing ATP.
• C. Chemical synapses with adjacent neurons.
• D. Myosin-actin contractile apparatus.

Answer: (A)

Excitable cells generate electrical signals through a shared setup of ion pumps and voltage-gated channels. The Na+/K+ pump keeps the sodium and potassium gradients across the membrane, which are essential for any rapid change in membrane potential. Voltage-gated channels then open in response to depolarization, allowing ions to flow and create the upstroke and repolarization of the action potential. In nodal (pacemaker) cells, this same principle applies to produce rhythmic impulses that set heart rate, even though the exact ions driving the upstroke can differ (often Ca2+ rather than Na+ in these cells). The presence of these pumps and channels is what makes nodal cells functionally similar to neurons in how they generate and propagate electrical signals. Mitochondria, chemical synapses with neurons, and contractile machinery are not the defining feature here: they’re either universal in many cells, not specific to electrical signaling, or not present in nodal tissue for contraction.

Excitable cells generate electrical signals through a shared setup of ion pumps and voltage-gated channels. The Na+/K+ pump keeps the sodium and potassium gradients across the membrane, which are essential for any rapid change in membrane potential. Voltage-gated channels then open in response to depolarization, allowing ions to flow and create the upstroke and repolarization of the action potential. In nodal (pacemaker) cells, this same principle applies to produce rhythmic impulses that set heart rate, even though the exact ions driving the upstroke can differ (often Ca2+ rather than Na+ in these cells). The presence of these pumps and channels is what makes nodal cells functionally similar to neurons in how they generate and propagate electrical signals. Mitochondria, chemical synapses with neurons, and contractile machinery are not the defining feature here: they’re either universal in many cells, not specific to electrical signaling, or not present in nodal tissue for contraction.