Definition

1. Noun:
   • A specialized bit of heart tissue that controls the heartbeat: The sinoatrial node is a small, specialized group of cells located in the right atrium of the heart. It functions as the heart's natural pacemaker by generating electrical impulses that initiate each heartbeat, thereby setting the rhythm and rate of the heart's contractions.

Usage Examples

• Noun:
  • The electrical signal originates in the sinoatrial node.
  • Damage to the sinoatrial node can cause an irregular heartbeat.
  • The sinoatrial node is often called the heart's natural pacemaker.

Advanced Usage

• "Sinoatrial node dysfunction": a medical condition where the sinoatrial node does not function properly, leading to an abnormal heart rhythm.
  • The patient was diagnosed with sinoatrial node dysfunction.

Variants and Related Words

• SA node (n): A common abbreviation for "sinoatrial node."
  • The SA node initiates the cardiac cycle.
• Pacemaker cells (n): The specialized cells within the sinoatrial node that generate electrical impulses.
  • The pacemaker cells in the sinoatrial node have automaticity.

Synonyms

• Cardiac pacemaker: The natural pacemaker of the heart.
• SA node: The abbreviated form.

Related Phrases and Terms

• Atrioventricular node (AV node) (n): A separate cluster of cells in the heart that receives impulses from the sinoatrial node and delays them before passing them to the ventricles.
  • The electrical impulse travels from the sinoatrial node to the atrioventricular node.

Noun

1. a specialized bit of heart tissue that controls the heartbeat