Transverse sinuses

Transverse sinuses
Dural veins. (Transverse sinuses labeled as "SIN. TRANS." at center right.
The transverse sinuses are formed by the tentorium cerebelli and drain into the right and left sigmoid sinuses.
Details
Source	confluence of sinuses, superior sagittal sinus
Drains to	sigmoid sinuses
Identifiers
Latin	sinus transversus durae matris
MeSH	A07.231.908.224
Dorlands /Elsevier	s_12/12739325
TA	A12.3.05.102
FMA	50763
Anatomical terminology []

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 along the interior surface of the occipital bone. They drain from the confluence of sinuses (by the internal occipital protuberance) to the sigmoid sinuses, which ultimately connect to the internal jugular vein. See diagram (at right): labeled under the brain as "SIN. TRANS." (for Latin: sinus transversus).

The transverse sinuses are of large size and begin at the internal occipital protuberance; one, generally the right, being the direct continuation of the superior sagittal sinus, the other of the straight sinus.

Each transverse sinus passes lateralward and forward, describing a slight curve with its convexity upward, to the base of the petrous portion of the temporal bone, and lies, in this part of its course, in the attached margin of the tentorium cerebelli; it then leaves the tentorium and curves downward and medialward (an area sometimes referred to as the sigmoid sinus) to reach the jugular foramen, where it ends in the internal jugular vein.

In its course it rests upon the squama of the occipital, the mastoid angle of the parietal, the mastoid part of the temporal, and, just before its termination, the jugular process of the occipital; the portion which occupies the groove on the mastoid part of the temporal is sometimes termed the sigmoid sinus.