Superior sagittal sinus
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| Vein: Superior sagittal sinus | |
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| Dural veins (Superior sagittal sinus labeled as "SIN. SAGITALLIS SUP." at top.) | |
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| Superior sagittal sinus laid open after removal of the skull cap. The chordæ Willisii are clearly seen. The venous lacunæ are also well shown; from two of them probes are passed into the superior sagittal sinus. | |
| Latin | sinus sagittalis superior |
| Gray's | subject #171 654 |
| Source | superior cerebral veins |
| Drains to | confluence of sinuses |
| MeSH | Cranial+Sinuses |
| Dorlands / Elsevier |
s_12/12739211 |
The superior sagittal sinus (also known as the superior longitudinal sinus), within a human cranium, is an area above/behind the brain, which allows blood veins to span the area, from the top of the head towards the back. It is believed that the cerebrospinal fluid drains through the arachnoid granulations into the dural venous sinuses of the superior sagittal sinus.
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[edit] Anatomy
The sinus drains, along the top and back of the brain, to the transverse sinuses, then to the sigmoid sinuses (at the center of the head), at the internal jugular vein. See diagram (at right): labeled above the brain as "SIN. SAGITALLIS SUP." (for Latin: sinus sagittalis superior).
The superior sagittal sinus occupies the attached or convex margin of the falx cerebri.
Commencing at the foramen cecum, through which it receives a vein from the nasal cavity, it runs from anterior to posterior, grooving the inner surface of the frontal, the adjacent margins of the two parietal lobes, and the superior division of the cruciate eminence of the occipital lobe; near the internal occipital protuberance, it deviates to either side (usually the right), and is continued as the corresponding transverse sinus.
It is triangular in section, narrow in front, and gradually increases in size as it passes backward.
Its inner surface presents the openings of the superior cerebral veins, which run, for the most part, obliquely forward, and open chiefly at the back part of the sinus, their orifices being concealed by fibrous folds; numerous fibrous bands (chordæ Willisii) extend transversely across the inferior angle of the sinus; and, lastly, small openings communicate with irregularly shaped venous spaces (venous lacunæ) in the dura mater near the sinus.
There are usually three lacunæ on either side of the sinus: a small frontal, a large parietal, and an occipital, intermediate in size between the other two.
Most of the cerebral veins from the outer surface of the hemisphere open into these lacunæ, and numerous arachnoid granulations (Pacchionian bodies) project into them from below.
The superior sagittal sinus receives the superior cerebral veins, veins from the diploë and dura mater, and, near the posterior extremity of the sagittal suture, veins from the pericranium, which pass through the parietal foramina.
[edit] Additional images
 Left parietal bone. Inner surface. |
 Frontal bone. Inner surface. |
 Base of the skull. Upper surface. |
 Diagrammatic representation of a section across the top of the skull, showing the membranes of the brain, etc. |
 Diagrammatic section of scalp. |
 Human brain dura mater |
[edit] See also
[edit] References
- This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
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