Straight sinus

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Straight sinus
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Dural veins (Straight sinus labeled as 'SIN. RECTUS' at center right.)
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Dura mater and its processes exposed by removing part of the right half of the skull, and the brain. (Straight sinus visible as blue line at center left.)
Details
Source inferior sagittal sinus, great cerebral vein
Drains to confluence of sinuses
Identifiers
Latin sinus rectus
TA98 A12.3.05.112
TA2 4853
FMA 50769
Anatomical terminology

The straight sinus, also known as tentorial sinus or the sinus rectus, is an area within the skull beneath the brain. It receives blood from the inferior sagittal sinus and the great cerebral vein, and drains into the confluence of sinuses.

Contents

Structure

The straight sinus is situated within the dura mater, where the falx cerebri meets the midline of tentorium cerebelli. [1] It forms from the confluence of the inferior sagittal sinus and the great cerebral vein. [1] [2] It may also drain blood from the superior cerebellar veins and veins from the falx cerebri. [1] In cross-section, it is triangular, contains a few transverse bands across its interior, and increases in size as it proceeds backward.[ citation needed ] It is usually around 5 cm long. [2]

Variation

The straight sinus is usually an unpaired structure. [2] However, there may be two straight sinuses, which may be one on top of the other or parallel. [2]

Function

The straight sinus allows blood to drain from the inferior center of the head outwards posteriorly. It receives blood from the inferior sagittal sinus, great cerebral vein, posterior cerebral veins, superior cerebellar veins and veins from the falx cerebri. [1]

Additional images

See also

Related Research Articles

Articles related to anatomy include:

Dura mater

Dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. The other two meningeal layers are the arachnoid mater and the pia mater. The dura surrounds the brain and the spinal cord. It envelops the arachnoid mater, which is responsible for keeping in the cerebrospinal fluid. It is derived primarily from the neural crest cell population, with postnatal contributions of the paraxial mesoderm.

Great cerebral vein

The great cerebral vein is one of the large blood vessels in the skull draining the cerebrum of the brain. It is also known as the "vein of Galen", named for its discoverer, the Greek physician Galen. However, it is not the only vein with this eponym.

Cerebral circulation

Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain. The rate of cerebral blood flow in an adult human is typically 750 milliliters per minute, or about 15% of cardiac output. Arteries deliver oxygenated blood, glucose and other nutrients to the brain. Veins carry "used or spent" blood back to the heart, to remove carbon dioxide, lactic acid, and other metabolic products. Because the brain would quickly suffer damage from any stoppage in blood supply, the cerebral circulatory system has safeguards including autoregulation of the blood vessels. The failure of these safeguards may result in a stroke. The volume of blood in circulation is called the cerebral blood flow. Sudden intense accelerations change the gravitational forces perceived by bodies and can severely impair cerebral circulation and normal functions to the point of becoming serious life-threatening conditions.

Epidural space

In anatomy, the epidural space is the potential space between the two layers of the dura mater.

Posterior cranial fossa Area of the cranium containing the brainstem and cerebellum

The posterior cranial fossa is part of the cranial cavity, located between the foramen magnum and tentorium cerebelli. It contains the brainstem and cerebellum.

Falx cerebri

The falx cerebri, also known as the cerebral falx, is a large, crescent-shaped fold of meningeal layer of dura mater that descends vertically in the longitudinal fissure between the cerebral hemispheres of the human brain. The falx cerebri attaches anteriorly at the crista galli in proximity to the cribriform plate and to the frontal and ethmoid sinuses. Posteriorly, it is connected with the upper surface of the cerebellar tentorium. Its superior margin is attached at midline to the internal surface of skull, as far back as the internal occipital protuberance. The superior sagittal sinus is contained in the superior margin of the falx cerebri and overlies the longitudinal fissure of the brain. The inferior sagittal sinus is contained in the inferior margin of the falx cerebri and arches over the corpus callosum, deep in the longitudinal fissure. The falx cerebri is named for its sickle-like form.

Cerebellar tentorium A vertebrate brain structure separating the cerebellum from the occipital lobes

The cerebellar tentorium or tentorium cerebelli is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.

Brain herniation Potentially deadly side effect of very high pressure within the skull

Brain herniation is a potentially deadly side effect of very high pressure within the skull that occurs when a part of the brain is squeezed across structures within the skull. The brain can shift across such structures as the falx cerebri, the tentorium cerebelli, and even through the foramen magnum. Herniation can be caused by a number of factors that cause a mass effect and increase intracranial pressure (ICP): these include traumatic brain injury, intracranial hemorrhage, or brain tumor.

Cavernous sinus

The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.

Confluence of sinuses

The confluence of sinuses , torcular Herophili, or torcula is the connecting point of the superior sagittal sinus, straight sinus, and occipital sinus. It is found deep to the occipital protuberance of the skull. Blood arriving at this point then proceeds to drain into the left and right transverse sinuses. The superior sagittal sinus often drains into one transverse sinus, and the straight sinus drains into the other.

Superior sagittal sinus

The superior sagittal sinus, within the human head, is an unpaired area along the attached margin of the falx cerebri. It allows blood to drain from the lateral aspects of anterior cerebral hemispheres to the confluence of sinuses. Cerebrospinal fluid drains through arachnoid granulations into the superior sagittal sinus and is returned to venous circulation.

Inferior sagittal sinus

The inferior sagittal sinus, within the human head, is an area beneath the brain which allows blood to drain outwards posteriorly from the center of the head. It drains to the straight sinus, which connects to the transverse sinuses. See diagram : labeled in the brain as "SIN. SAGITTALIS INF.".

Superior petrosal sinus One of the dural venous sinuses located beneath the brain

The superior petrosal sinus is one of the dural venous sinuses located beneath the brain. It receives blood from the cavernous sinus and passes backward and laterally to drain into the transverse sinus. The sinus receives superior petrosal veins, some cerebellar veins, some inferior cerebral veins, and veins from the tympanic cavity. They may be affected by arteriovenous malformation or arteriovenous fistula, usually treated with surgery.

Falx cerebelli Skull anatomy

The falx cerebelli is a small sickle shaped fold of dura mater, projecting forwards into the posterior cerebellar notch as well as projecting into the vallecula of the cerebellum between the two cerebellar hemispheres. The name comes from two Latin words: falx, meaning "curved blade or scythe", and cerebellum, meaning "little brain". Its base is attached, above, to the under and back part of the tentorium cerebelli; its posterior margin, to the lower division of the vertical crest on the inner surface of the occipital bone. The falx cerebelli generally lies somewhere between 2.8 and 4.5 cm in length and is approximately 1–2 mm thick.

Sigmoid sinus

The sigmoid sinuses, also known as the pars sigmoid, are venous sinuses within the skull that receive blood from posterior dural venous sinus veins.

Transverse sinuses

The transverse 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 to the sigmoid sinuses, which ultimately connect to the internal jugular vein. See diagram : labeled under the brain as "SIN. TRANS.".

Squamous part of occipital bone

The squamous part of occipital bone, is situated above and behind the foramen magnum, and is curved from above downward and from side to side.

Anterior cranial fossa

The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting frontal lobes of the brain. It is formed by the orbital plates of the frontal, the cribriform plate of the ethmoid, and the small wings and front part of the body of the sphenoid; it is limited behind by the posterior borders of the small wings of the sphenoid and by the anterior margin of the chiasmatic groove. The lesser wings of the sphenoid separate the anterior and middle fossae.

Cerebellar veins

Cerebellar veins are veins which drain the cerebellum.

References

PD-icon.svgThis article incorporates text in the public domain from page 655 of the 20th edition of Gray's Anatomy (1918)

  1. 1 2 3 4 Drake, Richard L.; Vogl, Wayne; Tibbitts, Adam W.M. Mitchell; illustrations by Richard; Richardson, Paul (2005). Gray's anatomy for students. Philadelphia: Elsevier/Churchill Livingstone. p. 795. ISBN   978-0-443-06612-2.
  2. 1 2 3 4 Saxena, R. C.; Beg, M. a. Q.; Das, A. C. (1 December 1974). "The straight sinus". Journal of Neurosurgery . 41 (6): 724–727. doi:10.3171/jns.1974.41.6.0724.