What is the sigmoid sinus?
In the human brain, there are a number of vessels that serve to ensure blood supply to the brain. The sigmoid sinus is a central blood vessel located at the back of the head.
The posterior skull is called the occipital bone and forms the entire posterior head area. The special thing about the venous conductor is its shape. In a cross-section of the brain, it can be clearly seen that it takes on an s-shaped form. From him go out many different branches that make the blood supply in deeper layers of tissue. Venous blood flows in the sigmoid sinus.
The vessel wall is thin-skinned. Although it is well-suited for the external supply of drugs and other messengers, it is also more susceptible to damage. The transport of messenger and nutrients in the sigmoid sinus is very fast. This means that substances in the blood can be transported via this blood conductor in a few seconds or minutes to its place of action. In addition, the sigmoid sinus serves as the main way of evacuating the venous blood from the brain.
Anatomy & Construction
The dura mater, the hard meninges that protectively surround the brain, forms duplications. This process creates cavities in the meninges. These are used by venous blood vessels to provide blood within the brain.
In the cavities, the blood is collected from the meninges, the brain area and the eye socket. It then flows into the internal jugular vein. This is located in the posterior fossa, the foramen jugulare. There is the Sinus sagittalis superior. This runs at the top of the Falx cerebri. The sinus sagittalis inferior runs at the bottom and ends in the sinus rectus.
Subsequently, the superior sagittal sinus and the inferior sinus sag together. From the confluence, the path continues as sinus transversus. This framed the posterior fossa laterally and from behind. Ventral, he moves on and goes over into the s-shaped curved sigmoid sinus. The sigmoid sinus ends in the jugular foramen. This is the place where the internal jugular vein originated.
Function & Tasks
The blood carries important messenger substances. These are vital for the supply of organs and vessels. These include, for example, cells, hormones or protein-containing blood plasma. Thus the blood occupies a central function of the transport. Through the veins and arteries, the various agents are led to organs and derived again.
The sigmoid sinus is an integral part of many vessel branches in this system. He is responsible for a wide area in the back skull. Through his activity, the supply of the brain is essentially ensured. In addition, it takes over the removal of the brain blood instead. This means that, for example, hormones produced in the pituitary gland or the posterior pituitary gland can be rapidly removed from the brain by the sigmoid sinus and reach the organs where they are supposed to be effective.
In addition, heat regulation takes place via the blood. This ensures the correct temperature in the brain via the sigmoid sinus. In surgical procedures in the head area, the sigmoid sinus often serves as an access route. Due to its location and size, it can be used by surgeons to make their way through the cranial wall to the cerebellopontine angle. The sigmoid sinus supplies the upper veins inside the skull. Due to its shape, it offers many opportunities for diversions.
Common diseases of the blood vessels in the entire human body are inflammations. In this disease, a blood clot forms within a blood conductor. The sigmoid sinus is very susceptible to sinus vein thrombosis.
This can be triggered by middle ear suppuration. This is initially not noticed by the patient. If it continues to grow, it will congestion of the blood and first complaints. These express themselves in pain in the affected region as well as feelings of tension. Although sinus vein thrombosis is uncommon, there is a risk of death from a stroke due to the clot. Most patients are between the ages of 30 and 40 years. In addition, the clot can come loose and be transported to the heart. From there it flows following the stream to the lungs. Clogged the clot, which is also called a thrombus at this point a blood vessel, it comes to the patient to a pulmonary embolism. This is classified as life threatening.
The vascular wall of veins in the human body are thin. This leaves them vulnerable to lesions. Once the sigmoid sinus is damaged, problems in supplying the brain become one. In addition, the removal of venous cerebral blood is no longer guaranteed. Veins are assigned a central role in diseases such as cancer. In them, cancer cells are transported to every part of the body. Once they break away from a formed tumor, they enter the bloodstream. Regardless of where they are transported, the cancer cells can form new metastases at this site. This creates new tumors and the disease continues to spread unintentionally.