Definition

1. Noun:
   • An S-shaped dural sinus on the temporal and occipital bones: The sigmoid sinus is a paired venous channel within the dura mater (the tough outer membrane of the brain). It has a characteristic S-shaped curve and is located on the inner surface of the temporal and occipital bones of the skull. It is a major pathway for draining deoxygenated blood from the brain.

Usage Examples

• Noun:
  • The sigmoid sinus is a crucial structure for cerebral venous drainage.
  • Thrombosis of the sigmoid sinus is a serious medical condition.
  • The surgeon carefully avoided the sigmoid sinus during the procedure.

Advanced Usage

• "Sigmoid sinus groove": The bony indentation on the inner skull surface where the sigmoid sinus travels.
  • The sigmoid sinus groove was clearly visible on the cranial CT scan.
• "Sigmoid sinus junction": Refers to the point where the sigmoid sinus connects to another venous structure, such as the transverse sinus or the internal jugular vein.
  • The contrast study highlighted the patency of the sigmoid sinus junction.

Variants and Related Words

• Sigmoid (adj): Shaped like the letter "S" or the Greek letter sigma (Σ). This term describes the sinus's characteristic form.
  • The colon has a sigmoid section.
• Venous sinus (n): A general term for any of the venous channels located between the layers of the dura mater that drain blood from the brain.
  • The superior sagittal sinus is another major venous sinus.

Synonyms

• Sigmoid venous sinus: A more formal, descriptive synonym.
• Pars sigmoidea sinus transversi: A partial Latin anatomical term sometimes used to describe the S-shaped portion of the transverse sinus.

Related Phrases

• Sigmoid sinus thrombosis: The formation of a blood clot within the sigmoid sinus.
  • Otogenic infections can lead to sigmoid sinus thrombosis.
• Sigmoid sinus plate: The thin layer of bone separating the sigmoid sinus from the mastoid air cells in the ear.
  • Erosion of the sigmoid sinus plate is a surgical concern in chronic mastoiditis.

Noun

1. an S-shaped dural sinus on the temporal and occipital bones