When a Pacemaker Potential in the SA Node Reaches Threshold

question 65

Multiple Choice

When a pacemaker potential in the SA node reaches threshold,

• A)the permeability to K⁺ ions increases.
• B)many voltage-gated Ca²⁺ channels open.
• C)voltage-gated Ca²⁺ channels close.
• D)RMP has been restored.
• E)permeability of the cell does not change.

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Definitions:

Unit Sales

The total number of individual items or units that are sold within a specific period.

Traceable Fixed Expense

Fixed costs that can be directly linked to a specific segment of a business, like a product line or department.

Price Increase

An adjustment made to the selling price of goods or services, often due to factors such as inflation, increased costs of production, or improvements in quality.

Percentage Change

A mathematical calculation that shows how much a quantity has increased or decreased as a proportion of its previous value.