The superior sagittal sinus (also known as the superior longitudinal sinus), within the

human head In human anatomy, the head is at the top of the human body. It supports the face and is maintained by the human skull, skull, which itself encloses the human brain, brain. Structure The human head consists of a fleshy outer portion, which s ...

, is an unpaired dural venous sinus lying along the attached margin of the falx cerebri. It allows blood to drain from the lateral aspects of the anterior cerebral hemispheres to the confluence of sinuses.

Cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ...

drains through

arachnoid granulations Arachnoid granulations (also arachnoid villi, and Pacchionian granulations or bodies) are small outpouchings of the arachnoid mater and subarachnoid space into the dural venous sinuses of the brain. The granulations are thought to mediate the d ...

into the superior sagittal sinus and is returned to the venous circulation.

Structure

It is triangular in section. It is narrower anteriorly, and gradually increases in size as it passes posterior-ward. It commences at the foramen cecum, through which it receives emissary veins from the nasal cavity. It passes posterior-ward along its entire course. It is accommodated within a groove which runs across the inner surface of the

frontal bone In the human skull, the frontal bone or sincipital bone is an unpaired bone which consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bo ...

, the adjacent margins of the two parietal lobes, and the superior division of the cruciate eminence of the

occipital lobe The occipital lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The name derives from its position at the back of the head, from the Latin , 'behind', and , 'head'. The occipital lobe is the ...

. Near the internal occipital protuberance, it deviates to either side (usually the right) before draining into the confluence of sinuses, continuing as the corresponding

transverse sinus 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 for transverse sinus, groove along the interior ...

. The superior sagittal sinus is usually divided into three parts: anterior (foramen cecum to bregma), middle (bregma to lambda), posterior (lambda to confluence).Salunke, P., Sodhi, H. B. S., Aggarwal, A., Ahuja, C. K., Dhandapani, S. S., Chhabra, R., & Gupta, S. K. (2013). Is ligation and division of anterior third of superior sagittal sinus really safe? Clinical Neurology and Neurosurgery, 115(10), 1998–2002. http://doi.org/10.1016/j.clineuro.2013.06.003 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 (chordae Willisii) extend transversely across the inferior angle of the sinus; and, lastly, small openings communicate with irregularly shaped venous spaces (venous lacunae, also called 'lateral lacunae' or 'lacunae laterales') in the dura mater near the sinus.

Venous lacunae

There are usually three lacunae 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.

Tributaries

The superior sagittal sinus receives the superior cerebral veins, veins from the

diploë Diploë ( or ) is the spongy cancellous bone separating the inner and outer layers of the cortical bone of the skull. It is a subclass of trabecular bone. In the cranial bones, the layers of compact cortical tissue are familiarly known as the ...

and dura mater, and, near the posterior extremity of the sagittal suture, veins from the pericranium, which pass through the parietal foramina.

Function

drains through

into the superior sagittal sinus and is returned to venous circulation.

Additional images

File:Sobo 1909 590.png, Brain with sagittal sinus at centre, with various lacunae. File:Gray133.png, Left parietal bone. Inner surface. File:Gray135.png, Frontal bone. Inner surface. File:Gray193.png, Base of the skull. Upper surface. File:Gray769.png, Diagrammatic representation of a section across the top of the skull, showing the membranes of the brain, etc. File:Gray1196.png, Diagrammatic section of scalp. File:Human brain dura mater description.JPG, Human brain dura mater File:Slide6Neo.JPG, Meninges and superficial cerebral veins. Deep dissection. Superior view. File:Slide7Neo.JPG, Meninges and superficial cerebral veins. Deep dissection. Superior view.

References

External links

* http://neuroangio.org/venous-brain-anatomy/venous-sinuses/ {{Authority control Veins of the head and neck