External carotid artery
The external carotid artery supplies the soft tissues and bones of the skull, as well as the throat, larynx, thyroid and the hard meninges. It emerges at the carotid bifurcation from the arteria carotis communicans and is usually the smaller artery of the two carotid arteries. It is usually located in front of the inner carotid artery and runs between the musculus stylopharyngeus, the musculus stylohyoideus and the posterior part of the musculus digastricus.
In its course it is crossed by the hypoglossal nerve and the glossopharyngeal nerve. In the angle of the jaw it divides into its end branches: the maxillary artery and the superficial temporal artery. From these two branches numerous branches to the different structures of the skull and neck emerge.
Thus the arteria carotis externa supplies the tongue and throat via the arteria lingualis and the arteria pharyngea ascendens. The thyroid gland is supplied with blood via the arteria thyroidea superior and the face via the arteria facialis and its end branches. The arteria occipitalis supplies the back of the head, the arteria auricularis posterior the back of the ear and the arteria maxillaris the jaw.
From these larger branches, numerous small branches emerge, which in turn supply the soft tissues of the skull and neck. The A. carotis externa gives off 3 anterior branches: the A. thyroidea superior (thyroid gland, larynx), the A. lingualis (floor of the mouth, tongue) and the A. facialis (superficial face). It also gives off a medial branch, the A. pharyngea ascendens (pharyngeal to base of skull) and two posterior branches, the A. occipitalis (occiput) and the A. auricularis posterior (ear region).
Finally, it gives off two more end branches, the A. maxillaris (masticatory muscles, posterior inner part of the facial skull, meninges) and the A. temporalis superficialis (temporal region, part of the ear). The A. carotis externa supplies the outer skull and parts of the neck. It delivers branches to the larynx, thyroid (A. thyroidea superior) and pharynx (A. pharyngea ascendens).
In the oral area it supplies the floor of the mouth, the tongue (A. lingualis) and the masticatory muscles (A. maxillaris). It also gives branches to the superficial face (A. facialis), the temporal region (A. temporalis superficialis), the back of the head (A. occipitalis) and also to part of the ear. It also supplies parts of the interior of the skull, such as the base of the skull, the rear inner part of the facial skull and the meninges.
An aneurysm is a weak spot in the wall of a vessel. Usually an asymptomatic aneurysm occurs first, which is often discovered by chance. However, if the vessel ruptures due to a sudden rise in blood pressure, it can lead to life-threatening bleeding in the skull.
The aneurysms often occur at the arteries of the Circulus Arteriosus. Mostly they are located at the anterior common artery, but also the cerebral media, the internal carotid artery and the posterior common artery are often affected. If the aneurysm ruptures, bleeding occurs in the space between the arachnoid and the inner meninges.
Typical symptoms are very strong, suddenly occurring, so-called destruction headache and neck stiffness. Bleeding in the skull must be detected and treated as quickly as possible, otherwise the increase in volume caused by the bleeding will put pressure on the brain and cause the brain tissue to shift to the opposite side. As a result, important structures can be squeezed or kinked and infarcts (tissue loss) can occur in the affected areas. Depending on the area, this has considerable effects (e.g. motor failures) and can often lead to death. Therefore, early detection and therapy before the rupture is essential for a good prognosis.