Transverse sinus
Sinus transversus
A large paired dural venous sinus that curves round the back of the skull from the confluence of sinuses towards the jugular foramen.
At a glance
- English
- Transverse sinus
- Latin (TA2)
- Sinus transversus
- System
- Vein
- Region
- Head
- Side
- Paired, left and right
About the transverse sinus
The transverse sinuses, also called the lateral sinuses, are two broad venous channels in the dura at the back of the skull. Each begins at the internal occipital protuberance and runs outwards and forwards within the fixed edge of the tentorium cerebelli, lying in a groove on the inner surface of the occipital squama and then on the parietal bone near its mastoid angle. Its course bows slightly upwards.
Usually one transverse sinus, more often the right, carries straight on from the superior sagittal sinus, while the other continues from the straight sinus; the two are linked at the confluence of sinuses. As a result they are often unequal, the one carrying the superior sagittal blood being larger. Each grows wider as it travels outwards. In section the horizontal part is prism-shaped, and the curved part rounder.
Near the base of the petrous temporal bone the sinus leaves the tentorium and bends downwards and medially. This curved continuation, lying on the mastoid temporal bone and then on the occipital bone's jugular process, is the sigmoid sinus, which ends at the jugular foramen in the internal jugular vein. At the point of the bend the superior petrosal sinus joins it.
The transverse sinus also receives some veins from the under surfaces of the cerebrum and cerebellum, veins from the diploe and, when present, the petrosquamous sinus, which runs back along the junction of the squamous and petrous temporal bone. Through mastoid and condylar emissary veins it communicates with the veins outside the skull. A narrowed transverse sinus is a recognised finding in idiopathic intracranial hypertension, and stenting it is one treatment; the sinus is also commonly involved in cerebral venous thrombosis.
Course and drainage
- Begins at
- Starts beside the internal occipital protuberance, usually continuing the superior sagittal sinus on one side and the straight sinus on the other.
- Drains into
- Continues as the sigmoid sinus near the base of the petrous temporal bone, ending at the jugular foramen in the internal jugular vein.
- Drains
- Carries blood from the confluence of sinuses and drains the superior petrosal sinus, inferior cerebral and cerebellar veins and diploic veins.
Anthromica
See the transverse sinus where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
