Internal carotid artery

The internal carotid artery or internal carotid artery is one of the brain-supplying arteries. In humans and some other mammals provides them apart from the brain and the eye. The branch is called the ophthalmic artery.

Development in humans

It is caused by splitting of the common carotid artery, the other branch is usually somewhat weaker external carotid artery, which supplies the outer portions of the head and sometimes the neck organs as well as in the skull, the meninges. Exist between two many connections ( anastomoses ).

On disposal of the internal carotid artery, the carotid sinus, are pressure receptors ( also Presso or baroreceptors called ), which monitor the blood pressure in the arterial system and transmit the information to the cardiovascular center in the brain and represent the receptor area for the Karotissinusreflex. In addition, chemoreceptors are found at the origin of the internal carotid artery in the so-called carotid body that monitor the content of carbon dioxide, oxygen and pH in the blood.

The internal carotid artery is accompanied by a sympathetic nerve plexus, which originates from the upper sympathetic chain.

Sections

The course of the internal carotid artery can be divided into four sections: cervical part, petrous, pars cavernosa, pars cerebralis.

Cervical part

The cervical part ( " neck " ) extends from the outlet of the common carotid artery until it enters the skull base through the outer opening of the Karotiskanals ( carotid canal ). In its initial portion of the internal carotid artery is usually behind ( posterior to ) the external carotid artery, it then passes on to the medial ( towards the middle ) and reaches the base of the skull. Throughout the course of the cervical part, the internal carotid artery gives off no branch.

Petrous

The petrous ( " petrous part " ) runs within the same portion of the temporal bone and is in humans at about 3 cm long. She pulls first cranially, ie upwards, then describes, however, in the anterior wall of the tympanic cavity ( Paries carotid ) taking a bow to the front and to the middle ( anteromedially ) toward sphenoid body. The sheet is referred to as " Karotisknie ". The petrous dismisses several branches to the tympanic cavity ( arteries caroticotympanicae ) and a branch to the pterygoid canal ( canalis artery pterygoid ). In the area of the inner opening of Karotiskanals the internal carotid artery usually only of dura mater ( dura mater) is covered and faces the foramen lacerum on. The space between the wall of the Karotiskanals and the internal carotid artery is occupied by a network of veins known as venous plexus internal carotid. This venous plexus connects the nearby intracranial cavernous sinus with the pterygoid plexus that is outside of the skull. This compound can play a crucial role in the pathogenesis of meningitis ( meningitis ).

Pars cavernosa

Immediately on the inside of the skull base, the internal carotid artery passes through the cavernous sinus. This section is called the pars cavernosa ( " sponge plant part "). The artery here makes another " S" -shaped bend from the rear and bottom of the front and above, which is referred to as a trap or " carotid siphon ." This section describes the internal carotid artery is a branch to the posterior pituitary gland ( pituitary artery inferior ) branches to the trigeminal ganglion ( Rami ganglionares trigeminales ), to the surrounding dura mater ( meningeal ramus ), and cavernous sinus ( cavernous sinus Ramus ).

Pars cerebralis

After opening the dura medial to the anterior clinoid process, the internal carotid artery passes into the pars cerebralis ( " part of the brain "). The pars cerebralis is located in the subarachnoid space at the base of the brain. It runs in this section of the rear bottom to top front. You are immediately after passage of the dura mater as the ophthalmic artery branch from. This extends to the optic nerve ( optic nerve ) to the eye. Most comes from the pars cerebralis posterior communicating artery also produced, which is part of the circle of Willis, and the front connects to the rear flow field. Other branches are the anterior choroidal artery, which supplies various brain structures with blood, and the superior hypophysial artery. The internal carotid artery then divides into the anterior ( anterior cerebral artery ) and the middle cerebral artery ( MCA ), which together serve large portions of the cerebrum. The division point is designated as the " carotid T".

Variants

A rare variant of the rear cerebral artery ( posterior cerebral artery ) arises primarily from the internal carotid artery. Compounds of the vessels of both sides and the basilar artery form the circle of Willis ( circle of Willis ).

Comparative Anatomy

In horses and dogs, the internal carotid artery also supplied the brain. In the horse, the artery runs kaudodorsal the medial airbag Bay, an extension of the Eustachian tube ( auditory tube ). In even-toed ungulates, cats and guinea pigs, the internal carotid artery regresses outside the cranial cavity and is functionally replaced by other vessels. In artiodactyls and cats, this is the maxillary artery, a branch of the external carotid artery, which also makes you wonder nets at the base of the brain. By joining wonders networks and the internal carotid artery supplying the brain, the cerebral artery is formed. In guinea pigs, about 40 % of the inflow to the circle of Willis are from the internal ophthalmic artery ( ophthalmic artery interna).

Pathology

In particular, the initial segment of the internal carotid artery is a predilection for the formation of atherosclerotic plaques. These can either constrict the vessel or fully close or cause an embolism by a stroke. The dissection is a cracking, which can also open out in the acute vessel closure, here is often a trauma as a cause before. In the course of intracranial ( within the skull ) sometimes form small sacs ( aneurysms ) that result in rupture of the high acute picture of subarachnoid hemorrhage.

Swell

Theodor H. Schiebler (ed.): Anatomy. Springer, Heidelberg 2005, ISBN 3-540-21966-8.
U. Gille: cardiovascular and defense system Angiologia. In: Franz- Viktor Salomon ( ed.): Anatomy for veterinary medicine. Enke, Stuttgart 2004, ISBN 3-8304-1007-7, pp. 404-463.
Helga Fritsch, Wolfgang Kühnel: Pocket Atlas Anatomy, Volume 2, Internal Organs. Georg Thieme Verlag, 2009, ISBN 978-3-13492-110-6, page 50
Walther Graumann: Handbook of Anatomy: Internal organs, circulatory system, defense system. 1994, ISBN 3-437-00732-7, pp. 441-445.

Cerebral circulation Anastomosis Sympathetic trunk Guttural pouch

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