Anatomy & Organs

Dura mater – structure, function & diseases

Dura mater

The dura mater ( hard meninges ) serves essentially to protect the brain from external influences. It is one of three meninges that enclose the human brain.

This three-layer meninges (meninx encephali) consists of connective tissue and merges into the so-called spinal cord skin in the spinal canal. The dura mater is particularly tight, lies on the outside and has blood vessels in its invaginations . These can transport blood from the brain. In addition, there are many pain receptors in the dura mater, which is why it is very sensitive.

What is the dura mater?

The meninges also include the soft meninges ( pia mater ), which is mainly responsible for the supply of nutrients to the brain tissue. The cobweb skin ( Arachnoidea mater ) lies between the hard and soft meninges.

It has many smaller blood vessels and also handles the exchange between the brain fluid (liquor) and the blood . With the help of the spaces between the three meninges, shocks and changes in brain volume can be compensated. Physiologically, there is no space between the dura mater and the skull bones. That’s because the dura mater is made up of two sheets called sheets. The outer layer of the dura mater is also the inner periosteum of the skull . Again, the inner sheet of the dura mater connects very snuggly with the cobweb skin.

However, due to bleeding or trauma , an epidural space can develop there, which may be composed of loose connective tissue , fat, veins and lymphatic vessels . If necessary, injections can be given into this gap to numb the exiting nerve roots. Over the larger clefts of the brain, the dura septa form what are known as dura septa, often tent-like linings.

The largest septum extends in the shape of a crescent in the upper skull and separates the two cerebral hemispheres . Likewise, both sections of the cerebellum are separated by a dura septum. In addition, the dura mater is able to form venous blood collection vessels that drain blood from the meningeal layers and the brain towards the heart .

Anatomy & Structure

The entire meninges are supplied with blood by three arteries that branch off from the external carotid artery . The fifth cranial nerve takes over the sensitive supply of the meninges. He is also responsible for the pain and pressure sensitivity of the human face. Hence the very high sensitivity, especially of the dura mater.It is of crucial importance for the processing of pain stimuli in the head. The pain is very often caused by increased pressure on the meninges. An important cause of this can be bleeding in the brain. Meningitis (inflammation of the meninges) also causes severe pain in the head. Meningitis is caused by viruses, bacteria or, more rarely, fungi. The more the immune system is weakened, the easier it is to cause meningitis. Viruses are more likely to cause meningitis, but bacteria are more dangerous in this regard.

Function & Tasks

Bacterial meningitis can lead to life-threatening conditions within a few hours and can quickly lead to death. In the event of survival, permanent mental disabilities are no exception. Triggers are often meningococci or pneumococci . Meningitis usually begins with sudden flu symptoms such as fever , body aches , headaches and chills .

A little later, however, symptoms such as a stiff neck and especially pain when moving the head to the chest appear. The meninges are stretched, which causes severe pain due to their inflammation. Photophobia can also become noticeable in those affected. If these signs appear, a doctor should be consulted immediately. Children and infants should be vaccinated against meningitis in good time. Bacterial meningitis usually requires hospitalization.

Both the patient and all contacts are treated with antibiotics . If therapy for meningitis begins early, the disease usually heals without consequences. Only in rare cases does hearing damage or various signs of paralysis remain. In addition, there may be noticeable behavioral changes once meningitis has reached the brain.

Diseases

Since the collagenous connective tissue that makes up the dura mater is particularly taut, it is relatively easy for entrapment in various areas of the brain to occur. These entrapments occur primarily in the so-called dura septa. They are mainly caused by bleeding, tumors or other extensive changes in the cranial fossa. A distinction is made between axial and lateral entrapment.The axial is a symmetrical incarceration, which spreads equally in both cerebral hemispheres. The upper axial entrapment exerts pressure on the midbrain , the lower on the brainstem . In contrast, lateral incarceration occurs in unilateral space-occupying processes. It brings with it the danger that the brain crus will be pushed to the opposite side, which can lead to more or less severe brain damage there. If the inflammation of the meninges spreads to the brain itself, it is called meningoencephalitis . The three meninges can also be affected by nervous irritation in the head area.

They have in common occurring headaches, persistent sensitivity to light and strong noises, and often also nausea and vomiting . These symptoms also appear in other diseases of the meninges such as migraine or subarachnoid hemorrhage . This bleeding often occurs after accidents or pressure on the brain, which damages the spaces between the meninges by bleeding.

Lisa Newlon
Website | + posts

Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.