The sigmoid sinuses (sigma- or s-shaped hollow curve), also known as the , are paired dural venous sinuses within the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

that receive blood from posterior

transverse sinus The transverse sinuses (left and right lateral sinuses), within the human head, are two areas beneath the brain which allow blood to drain from the back of the head. They run laterally in a groove for transverse sinus, groove along the interior ...

es.

Structure

The sigmoid sinus is a dural venous sinus situated within the dura mater. The sigmoid sinus receives blood from the

es, which track the posterior wall of the cranial cavity, travels inferiorly along the

parietal bone The parietal bones ( ) are two bones in the skull which, when joined at a fibrous joint known as a cranial suture, form the sides and roof of the neurocranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four bord ...

temporal bone The temporal bone is a paired bone situated at the sides and base of the skull, lateral to the temporal lobe of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples where four of the cranial bone ...

and

occipital bone The occipital bone () is a neurocranium, cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone lies over the occipital lob ...

, and converges with the

inferior petrosal sinuses The inferior petrosal sinuses are two small sinuses situated on the inferior border of the petrous part of the temporal bone, one on each side. Each inferior petrosal sinus drains the cavernous sinus into the internal jugular vein. Structure Th ...

to form the

internal jugular vein The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posteri ...

. Each sigmoid sinus begins beneath the

and follows a tortuous course to the

jugular foramen A jugular foramen is one of the two (left and right) large foramina (openings) in the base of the skull, located behind the carotid canal. It is formed by the temporal bone and the occipital bone. It allows many structures to pass, including the ...

, at which point the sinus becomes continuous with the

Function

The sigmoid sinus receives blood from the transverse sinuses, which receive blood from the posterior aspect of the skull. Along its course, the sigmoid sinus also receives blood from the

cerebral vein In human anatomy, the cerebral veins are veins in the cerebral circulation which drain blood from the cerebrum of the human brain The human brain is the central organ (anatomy), organ of the nervous system, and with the spinal cord, com ...

cerebellar vein The cerebellar veins are veins which drain the cerebellum. They consist of the superior cerebellar veins and the inferior cerebellar veins (dorsal cerebellar veins). The superior cerebellar veins drain to the straight sinus and the internal cer ...

diploic vein The diploic veins are large, thin-walled valveless veins that channel in the diploë between the inner and outer layers of the cortical bone in the skull, first identified in dogs by the anatomist Guillaume Dupuytren. A single layer of endothel ...

s, and emissary veins.

References

External links

* http://neuroangio.org/venous-brain-anatomy/venous-sinuses/ {{Authority control Veins of the head and neck