The sigmoid sinuses (sigma- or s-shaped hollow curve), also known as the , are venous sinuses within the
skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...
that receive blood from posterior
dural venous sinus veins.
Structure
The sigmoid sinus is a
dural venous sinus situated within the
dura mater
In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...
. The sigmoid sinus receives blood from the
transverse sinuses, which track the posterior wall of the cranial cavity, travels inferiorly along the
parietal bone,
temporal bone and
occipital bone, and converges with the
inferior petrosal sinuses 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 poste ...
.
Each sigmoid sinus begins beneath the
temporal bone 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
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 poste ...
.
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 veins,
cerebellar veins,
diploic veins, and
emissary vein
The emissary veins connect the extracranial venous system with the intracranial venous sinuses. They connect the veins outside the cranium to the venous sinuses inside the cranium. They drain from the scalp, through the skull, into the larger men ...
s.
See also
*
Dural venous sinuses
References
External links
* http://neuroangio.org/venous-brain-anatomy/venous-sinuses/
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Veins of the head and neck