Definition

1. Noun:
   • A connecting vein in the scalp and head: An "emissary vein" is a type of blood vessel that connects the venous sinuses within the dura mater (the tough outer membrane of the brain) to veins located outside the skull.

Usage

• The term "emissary vein" is used in medical and anatomical contexts to describe specific vascular pathways.
• It is typically used in its singular or plural form ("emissary veins") when discussing cranial anatomy or potential routes for infection.

Examples

• Noun:
  • The surgeon was careful to avoid the emissary vein during the procedure.
  • Emissary veins can serve as a pathway for the spread of infection from the scalp to the intracranial sinuses.

Advanced Usage

• Clinical significance: In medical literature, "emissary veins" are often discussed in relation to their role in thermoregulation or as potential conduits for septic emboli.
  • The study focused on the role of the parietal emissary vein in cooling the brain.

Variants and Related Words

• Emissary (noun): A person or thing sent on a specific mission. (Note: This is the general, non-anatomical meaning of the root word).
• Venous emissary: A less common alternative term for "emissary vein."

Synonyms

• Connecting vein: A descriptive synonym emphasizing its function.
• Emissarium: The Latin-derived term used in precise anatomical nomenclature.

Notes on Meaning

• The term specifically refers to veins that drain blood from intracranial sinuses to extracranial veins. This direction of flow is a key part of its definition.
• It is not a general term for any vein in the head; it refers to a specific set of named vessels (e.g., parietal emissary vein, mastoid emissary vein).

Noun

1. one of several connecting veins in the scalp and head that drain blood from sinuses in the dura mater to veins outside the skull