View source for Sinus transversus

{{Infobox Vein |
  Name        = {{PAGENAME}} |
  Latin       = sinus transversus durae matris |
  GraySubject = 171 |
  GrayPage    = 657 |
  Image       = Gray488_blue.gif |
  Caption     = Dural veins. (Transverse sinuses labeled as "SIN. TRANS." at center right. |
  Image2      = Gray569.png |
  Caption2    = The ''transverse sinuses'' are formed by the [[tentorium cerebelli]] and drain into the right and left [[sigmoid sinuses]]. |
  DrainsFrom  = |
  Source      = [[confluence of sinuses]], [[superior sagittal sinus]] |
  DrainsTo    = [[sigmoid sinuses]] |
  Artery      = |
  MeshName    = Cranial+Sinuses |
  MeshNumber  = A07.231.908.224  |
  DorlandsPre  = s_12 |
  DorlandsSuf  = 12739325  |
}}



: ''For the transverse pericardial sinus, see: [[pericardial sinus]].''

The '''transverse sinuses''' (left and right lateral sinuses), within a human head, are two areas beneath the brain, which allow blood veins to span the area, from the back of the head towards the nose. They drain from the [[straight sinus]] and [[superior sagittal sinus]] (along the top and back of the brain) to the [[sigmoid sinuses]] (at the center of the head), at the [[internal jugular vein]].  ''See diagram (at right)'': labeled under the brain as "<small>SIN. TRANS.</small>" (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 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]]. 

The transverse sinuses are frequently of unequal size, with the one formed by the [[superior sagittal sinus]] being the larger; they increase in size as they proceed, from back to center. 

On transverse section, the horizontal portion exhibits a prismatic form, the curved portion has a semicylindrical form. 

They receive the blood from the superior petrosal sinuses at the base of the petrous portion of the [[temporal bone]]; they communicate with the veins of the [[pericranium]] by means of the [[mastoid]] and [[condyloid]] [[emissary vein]]s; and they receive some of the [[inferior cerebral]] and [[inferior cerebellar vein]]s, and some veins from the [[diploë]]. 

The [[petrosquamous sinus]], when present, runs backward along the junction of the squama and petrous portion of the temporal, and opens into the transverse sinus.

==Additional images==
{{clear}}
<gallery>
 Image:Gray133.png|Left parietal bone. Inner surface.
 Image:Gray567.png|Dura mater and its processes exposed by removing part of the right half of the skull, and the brain.
 Image:Gray570.png|The sinuses at the base of the skull.
 Image:Gray908.png|Horizontal section through left ear; upper half of section.
 Image:Gray1197.png|Drawing to illustrate the relations of the brain to the skull.
 Image:Gray1198.png|Relations of the brain and middle meningeal artery to the surface of the skull.
 Image:Gray1209.png|Left temporal bone showing surface markings for the tympanic antrum (red), transverse sinus (blue), and facial nerve (yellow).
</gallery>

==See also==
* [[Dural venous sinuses]]

==References==
* {{Gray's}}
{{Veins of the head and neck}}

[[Category:Head and neck]]
[[Category:Cardiovascular system]]

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