Common Carotid Artery, Internal Carotid Artery

Template:Infobox - arterie thumb|right|200px|Odstup arterií s oblouku aorty

Summary Information

• paired artery;
• the main artery for the head and partly for the neck;
• course of the artery – thoracic (caudal), cervical (cranial).

Course

In the thoracic region, the course of the left and right arteries differs:

• the right common carotid artery departs from braciocephalic trunk and enters the cranial region;
• The left common carotid artery departs from the convexity of the aortic arch in front of the trachea, covered in front by the manubrium sterni and attachments of infrahyoid muscles, the left brachiocephalic vein and the thymus;
  • On the left side of the left artery run the left n. vagus , left n. phrenicus , left pleura and the lung.

The cervical course of the arteries is identical, projecting into carotid triangle. IronBehind the sternoclavicular joint it progresses cranially and laterally:

• ventrally from the artery – m. sternocleidomastoideus, superficial layer of cervical fascia, platysma, in part of the course of the thyroid gland ;
• medial to the artery – trachea, oesophagus;
• dorsally from the artery – m. longus colli, m. longus capitis, truncus sympaticus, transverse processes of the 4th–6th cervical vertebrae.
• the artery is crossed by the middle thyroid vein, usually the superior thyroid vein.

In the carotid triangle , at the level of the C 3 –C 4 vertebrae (at the level of the upper edge of the thyroid cartilage), the artery divides into external carotid artery and internal carotid artery .

• At the point where the artery divides, it can be compressed against the spine and the pulse can be felt;
• carotid body – a small body at the branching point, a chemoreceptor for the amount of O2and CO2 in the blood (the body is nourished by branches from the external carotid artery )
• The common carotid artery runs in the neck together with the internal jugular vein, vagus nerve and the superior cervical nerve in the neurovascular cervical bundle, which is surrounded by the carotid sheath (part of the pretracheal fascia). The bundle contains the vein laterodorsally, the artery medially, the vagus nerve dorsally and the superior cervical nerve ventrally.

Links

Related Articles

• Aorta
• Carotid Endarterectomy
• External Carotid Artery
• Internal Carotid Artery

References

Template:Infobox - arterie __BEZOBSAHU__ náhled|vpravo|Angiogram náhled|vpravo|Angiogram náhled|vpravo|Výběr větví arteria carotis interna A. Internal Carotid is one of the two main branchesa. common carotid. It arises from its division in carotid triangle, which is located at the level of the upper border štítné chrupavky.

Supply Area

It supplies the contents of the orbit with the eyeball, eyelids, skin of the forehead and bridge of the nose, mucous membrane of the middle ear cavity, two areas of the meninges, pituitary gland and brain.

Course and Branching

When it divides, it goes dorsolaterally and the other branch a. external carotid ventromedially. A. carotid internal then continues cranially under the skull base and through carotid canal into the cranial cavity. On its way, it reaches medially, closer to the pharyngeal wall, and then into retrostyloid space. Throughout its course, it is in the cervical neurovascular bundle. It does not give off any branches in the neck.

• The carotid sinus is an enlarged beginning of the artery, in the wall of which there are pressure receptors informing about changes in blood pressure. The signal is conducted by the nerve via  carotid sinus branch from  glossopharyngeal nerve. By pressing the internal carotid artery at the sinus, a reflex decrease in blood pressure occurs.

Before entering the carotid canal, the internal carotid artery runs in the shape of a curved loop, and another S-shaped loop is formed by the carotid canal. From it, it emerges cranially and continues ventrally with a convex course in the cavernous sinus. This course is called the carotid siphon. After exiting the carotid canal, the artery is on the side of the body the sphenoid bone in the carotid sulcus.

In the carotid canal and in the cavernous sinus the artery sends out only small branches. The main division occurs after piercing through the cavernous sinus above the surface of the dura mater. According to its course the internal carotid artery is divided into cervical part, petrous part, cavernous part and cerebral part.

Cervical part

has no branches.

Petrous Part

•  caroticotympanic artery: small branches penetrate from the carotid canal into the mucosa of the middle ear cavity.
• artery to pterygoid canal - enters the pterygoid canal with the nerve.

Cavernous part

It supplies the surrounding structures.

•  trigeminal ganglion branch
• nerve root branch
• meningeal branch
• basal tentorial branch
• marginal tentorial
• r. cavernous sinus
• a. inferior pituitary gland

Cerebral part

Superior Hypophysial artery

• It separates just below the base of the brain and enters the upper part of the pituitary stalk.

Opthalmic Artery

• It starts from the arch of the internal carotid artery, goes forward into optic canal. It initially lies lateral to the strong  optic nerve, which after entering the orbit crosses it and continues towards the inner superior angle of the orbit.
• It supplies the entire contents of the orbit, including the eyeball, eyelids, skin of the frontal region, and the bridge of the nose. Its branches are:
  •  central retinal artery – a relatively thin branch that enters the optic nerve and goes with it to the intraocular surface of the retina.
  •  lacrimal artery – goes forward to the outer upper part of the orbit, for the lacrimal gland and conjunctiva of the eye. It has a connection to the  middle meningeal artery.
  •  ciliary and muscular arteries – arteries to the eye and branches to the eye muscles.
  •  supraorbital artery – goes under the roof of the orbit to the incisura supraorbitalis and from there upwards to the skin and muscles of the forehead.
  •  posterior ethmoidal artery – goes into the opening of the same name in the inner wall of the orbit, from there into posterior ethmoidal cells.
  •  anterior ethmoidal artery – passes through the anterior ethmoidal foramen, then through the cribriform plate from the anterior cranial fossa, where it gives off r. anterior meningeal for the dura mater.
  •  medial palpebral arteries – to the inner side of the upper and lower eyelids, where they anastomose with the lateral palpebral arteries.
  •  supratrochlear artery – as one of the final branches, it ends in the skin and muscles of the frontal region through the incisura supratrochlearis.
  •  dorsal nasal artery – the second of the final branches passes to the root and dorsum of the nose and anastomoses with branches from the  facial artery.

Anterior choroidal artery

It goes to the inner surface of the temporal lobe of the brain and from there to the wall of the lateral ventricle of the brain. There it branches intothe choroid plexus of the lateral ventricle.

Anterior cerebral artery

It continues between the two cerebral hemispheres and then around corpus callosum backwards. It branches along the medial surface of the frontal and parietal lobes of the cerebral hemisphere and extends over the edge of these lobes to a narrow strip of their superolateral surface.

Anterior communicating artery

A short transverse artery, it connects the right and left anterior cerebral arteries. It is a common site of aneurysmst.

Middle cerebral artery

It heads outward into the lateral fossa of the brain and from there branches to the outer surface of the cerebral hemisphere.

Posterior communicating artery

It arises directly from the trunk of the internal carotid artery or from the beginning  of the middle cerebral artery and joins the posterior cerebral artery..

Links

Related Articles

• Aorta
• Common Carotid Artery
• External Carotid Artery
• Cervical Neurovascular Bundle
• Glossopharyngeal Nerve