Name the conductile tissue in the heart located on the posterior wall of the right atrium that has the highest rate of depolarization in the heart.

Options

A. Medulla oblongata.
B. Atrioventricular (AV) node.
C. Sinoatrial (SA) node.
D. Cranial nerve X-Vagus nerve.

Answer

**Step-by-Step Solution:**

1. **Identify the Location**: The question specifies that we are looking for a conductile tissue located on the posterior wall of the right atrium.

2. **Recall the Conductive Tissues in the Heart**: The heart has several conductive tissues, including the Sinoatrial (SA) node, Atrioventricular (AV) node, Bundle of His, and Purkinje fibers.

3. **Determine the Tissue with the Highest Rate of Depolarization**: Among these tissues, the SA node is known for having the highest rate of depolarization. It generates impulses at a rate of approximately 70 to 75 beats per minute, making it the primary pacemaker of the heart.

4. **Conclude the Answer**: Therefore, the conductile tissue located on the posterior wall of the right atrium with the highest rate of depolarization is the **Sinoatrial (SA) node**.

**Final Answer**: Sinoatrial (SA) node

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