Straight sinus
Sinus rectus
A midline dural venous sinus along the junction of the falx cerebri and tentorium, draining the deep brain to the back of the head.
At a glance
- English
- Straight sinus
- Latin (TA2)
- Sinus rectus
- System
- Vein
- Region
- Head
- Side
- Single, on the midline
About the straight sinus
The straight sinus, also called the tentorial sinus, lies in the dura mater along the line where the falx cerebri and the tentorium cerebelli join. It runs in the midline from the free front edge of the tentorium backwards and slightly downwards to the internal occipital protuberance. It measures about five centimetres.
It begins where two vessels meet: the inferior sagittal sinus, from the lower edge of the falx, and the great cerebral vein, which brings blood from the deep structures of the brain. Along its course it also receives the superior cerebellar veins from the upper surface of the cerebellum, some posterior cerebral veins and small veins from the falx. Its cross-section is a triangle, it widens as it goes back, and a few fibrous bands cross its interior.
At its hind end it opens into the confluence of sinuses, the meeting point with the superior sagittal sinus, or turns directly into one of the transverse sinuses, most often the left. From there blood passes through the sigmoid sinus to the internal jugular vein. The straight sinus is therefore the main outlet for the deep venous system of the brain, which drains the thalamus, basal nuclei and deep white matter.
It is usually single, but it may be doubled, with two channels lying one above the other or side by side. Thrombosis of the straight sinus, often with the deep cerebral veins, can affect both thalami and is a serious form of cerebral venous thrombosis that needs urgent treatment. The sinus is also a landmark in surgery near the pineal region, where it lies just behind and above the operating field.
Course and drainage
- Begins at
- Formed at the front edge of the tentorium where the great cerebral vein meets the inferior sagittal sinus.
- Drains into
- Ends at the internal occipital protuberance in the confluence of sinuses, or directly in a transverse sinus, usually the left.
- Drains
- Drains the deep cerebral venous system, the upper cerebellum, the falx and parts of the medial hemispheres.
Anthromica
See the straight 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.
