Inferior petrosal sinus

Inferior Petrosal Sinus

Diagram showing the positions of the three principal sinuses at the base of the skull, with the Inferior Petrosal Sinus marked at the bottom.

The Inferior Petrosal Sinus is a blood vessel located in the human skull. It is part of the dural venous sinuses system, which is responsible for draining blood from the brain back to the heart.

Anatomy

The Inferior Petrosal Sinus begins near the jugular foramen, a large opening in the base of the skull. It runs along the groove between the temporal bone and the basilar part of the occipital bone, and ends at the sigmoid sinus, which continues as the internal jugular vein.

Function

The primary function of the Inferior Petrosal Sinus is to drain blood from the cavernous sinus into the internal jugular vein. It also receives blood from the medulla oblongata and the pons, two important structures in the brainstem.

Clinical Significance

The Inferior Petrosal Sinus is clinically significant because it can be used as a route for catheterization in the diagnosis and treatment of certain medical conditions. For example, it can be used to sample blood for the measurement of adrenocorticotropic hormone (ACTH) levels in the diagnosis of Cushing's syndrome.

See Also

• Superior petrosal sinus
• Cavernous sinus
• Dural venous sinuses