Definition

1. Noun:
   • The membrane surrounding the heart: The pericardial sac is the double-walled, fluid-filled sac that encloses the heart and the roots of the great blood vessels. It serves to protect the heart and reduce friction as the heart beats.

Usage

• The term "pericardial sac" is used in medical, anatomical, and biological contexts to refer specifically to this protective structure.
• It is often discussed in relation to conditions affecting it, such as inflammation (pericarditis) or fluid accumulation (pericardial effusion).

Examples

• Noun:
  • During the surgery, the surgeon carefully opened the pericardial sac to access the heart.
  • An ultrasound revealed a small amount of fluid in the pericardial sac, which is normal.
  • The pericardial sac consists of two main layers: the fibrous pericardium and the serous pericardium.

Advanced Usage

• "Pericardial sac" vs. "Pericardium": In precise anatomical terminology, the "pericardial sac" often refers specifically to the fibrous outer layer (the fibrous pericardium) along with the parietal layer of the serous pericardium that lines it. The term "pericardium" can be used more broadly to refer to the entire sac and its layers.
  • The inflammation was localized to the inner surface of the pericardial sac.

Variants and Related Words

• Pericardium (n): The broader term for the sac-like structure surrounding the heart; the pericardial sac is a part of the pericardium.
• Pericardial (adj): Of or relating to the pericardium or pericardial sac.
  • Pericardial fluid (the lubricating fluid within the sac).
  • Pericardial cavity (the potential space between the layers of the serous pericardium within the sac).

Synonyms

• Heart sac: A less formal, descriptive synonym.
• Pericardium: The standard medical term, often used interchangeably with "pericardial sac" in general contexts.

Related Phrases

• Pericardial effusion: An abnormal accumulation of fluid within the pericardial sac.
• Pericardial tamponade: A critical condition where fluid in the pericardial sac puts excessive pressure on the heart, impairing its function.
• Pericardial window: A surgical procedure to create an opening in the pericardial sac to drain excess fluid.

Noun

1. the membrane surrounding the heart