Where is the carotid artery located and what functions does it perform. Internal carotid artery, its topography, branches and areas supplied by them Parts of the internal carotid artery

The carotid artery (arteria carotis communis) is a large paired vessel whose main function is to supply blood to most of the head, brain, and eyes.

There are several definitions:

• Common carotid artery;
• Right and left;
• Internal and external.

From this publication, you will learn how many carotid arteries a person actually has and what functions each of them performs. But first, let's find out where this unusual name came from - the carotid artery.

Carotid artery: why is it called that?

Pressure on the carotid artery is perceived by its receptors (terminal formations of afferent nerve fibers) as an increase in pressure and begin to actively work to lower it. A person's heartbeat slows down, due to squeezing of blood vessels, oxygen starvation begins, which causes drowsiness. It is because of this property that the carotid artery got its name.

Attention! With a strong and prolonged mechanical effect on the carotid artery, consciousness can be turned off and even death. Do not try, for the sake of idle curiosity, to check what will happen if you press on the carotid artery. Carelessness can lead to irreversible consequences!

But still, everyone should know the location of the carotid artery: this may be needed to help the victim.

How to find the carotid artery?

Most often, the pulse is measured by the arm. But if the artery of the injured person is weakly palpable, then the heart rate is measured along the carotid artery in the neck.

From which side to measure?

It is better to do this with the right hand on the right side. When measuring the pulse of the left, you can clamp two arteries at once, and then the result will be unreliable.

Step-by-step instruction:

Carotid arteries: location and function

The common carotid or carotid artery is an artery that has two identical vessels:

• FROM right side(derives from the brachiocephalic trunk):
• FROM left side(from the aortic arch).

Both vessels have an identical anatomical structure and are directed vertically upward through the chest to the neck.

Above the upper edge of the sternocleidomastoid muscle, located near the trachea and esophagus, each vessel divides into the internal and external carotid arteries (the point of separation is called the bifurcation).

After branching, the internal artery forms an extension (carotid sinus), covered with multiple nerve endings and which is the most important reflex zone. Massage of this area is recommended for patients with hypertension as a method of self-lowering blood pressure during crises.

What is the outer branch responsible for?

The key function of the external branch is to provide reversed blood flow in order to help the vertebral branch and branches of the internal carotid artery in their narrowing.

Which organs supply the external branches with blood?

• Facial muscles;
• scalp;
• Roots of teeth;
• eyeballs;
• Separate sections of the dura mater;
• Thyroid.

Where does the internal branch of the carotid artery pass?

The internal branch enters the skull through a hole in the temporal bone with a diameter of 10 mm (intracranial location), forming at the base of the brain, together with the vertebral vessels, the circle of Willis - the main source of cerebral blood supply. From it, deep into the convolutions, the arteries depart towards the cortical centers, gray and white matter, and the nuclei of the medulla oblongata.

Segments of the internal carotid artery:

External branch of the carotid artery: diseases, symptoms

Unlike the internal carotid artery, the external carotid does not supply blood directly to the brain.

However, a violation of its normal operation can cause a number of pathologies, the treatment of which is carried out by surgical methods from the field of plastic, otolaryngological, maxillofacial and neurosurgery:

These diseases can be the result of:

• Facial trauma;
• Transferred rhinoplasty and otolaryngological operations;
• Unsuccessful procedures performed: extraction of teeth, punctures, washing of the sinuses, injections into the orbit;
• Hypertension.

The pathophysiological manifestation of this pathology is an arteriovenous shunt, through the drainage pathways of which arterial blood with high pressure is directed to the head. Such anomalies are considered as one of the causes of cerebral venous congestion.

According to various sources, angiodysplasias account for 5 to 14% of the total number of vascular diseases. These are benign formations (proliferation of epithelial cells), about 70% of which are localized in the face area.

Symptoms of angiodysplasia:

• cosmetic defects;
• Profuse hemorrhages, poorly amenable to standard methods of stopping bleeding;
• Throbbing pains in the head (mainly at night).

Severe bleeding during surgery can be fatal.

Possible pathologies of the carotid artery and the internal trunk

Such common diseases as tuberculosis, atherosclerosis, fibromuscular dysplasia, syphilis can lead to pathological changes in the carotid artery that occur against the background of:

• Inflammatory processes;
• Growth of the inner shell;
• Dissections in young patients (rupture of the internal arterial membrane with blood penetrating into the space between the walls).

The result of dissection can be stenosis (narrowing) of the diameter of the artery, in which oxygen starvation of the brain occurs, tissue hypoxia develops. This condition can lead to ischemic stroke.

Other types of pathological changes caused by narrowing of the carotid artery:

• trifurcation;
• Aneurysm;
• Abnormal tortuosity of the internal carotid artery;
• Thrombosis.

trifurcation is a term for the splitting of an artery into three branches.

There are two types:

• Front- division of the internal common carotid artery into anterior, basilar, posterior;
• rear- connection of a branch of three cerebral arteries (posterior, middle, anterior).

Carotid aneurysm: what is it and what are the consequences

Aneurysm- this is an expansion of a section of an artery with local thinning of the wall. This disease can be congenital, or it can develop after prolonged inflammation, muscle atrophy and their replacement with thinned tissue. Concentrates in the area of ​​intracranial segments of the internal carotid artery. A dangerous pathology that develops asymptomatically and can cause instant death.

Rupture of a thinned wall can occur if:

• Neck and head injuries;
• Physical or emotional overstrain;
• A sharp increase in blood pressure.

The accumulation of excess blood in the subarachnoid space can cause tissue compression and swelling of the brain. In this case, the survival of the patient depends on the size of the hematoma and the promptness of medical care.

carotid thrombosis

Thrombosis- one of the most common causes of cerebrovascular accident. It is worth dwelling on this disease, symptoms and methods of treatment in more detail.

Thrombi are formed mostly inside the carotid artery at the bifurcation site - the fork of the external and internal branches. It is in this area that the blood moves more slowly, which creates conditions for the deposition of platelets on the walls of blood vessels, their gluing, and the appearance of fibrin threads.

The formation of blood clots provokes:

The clinical manifestations of thrombosis depend on:

• The size of the thrombus and the rate of its formation;
• Conditions of collaterals.

In its course, carotid thrombosis can be:

• Asymptomatic;
• sharp;
• Subacute;
• Chronic or pseudotumor.

Separately, the rapid (progredient) course of the disease is considered with a thrombus growing in length and penetrating into the anterior and middle arteries of the brain.

Thrombosis at the level of the common trunk is characterized by the following symptoms:

• Complaints about tinnitus;
• short-term loss of consciousness;
• Complaints of severe pain in the head and neck;
• Weakness of chewing muscles;
• Visual disturbances.

Insufficient blood supply to the eyes can cause:

• cataract;
• Atrophy of the optic nerve;
• temporary blindness;
• Decreased visual acuity during physical exertion;
• The presence of pigment in the retina with concomitant atrophy.

With thrombosis of the internal carotid artery in the area before entering the skull, patients experience:

• Severe headaches;
• Loss of sensation in the legs and arms;
• Soreness of the scalp in the affected area;
• hallucinations, irritability;
• Problems with speech up to dumbness (with a left-sided lesion).

Symptoms of thrombosis of the intracranial section of the carotid artery:

• Disorders of consciousness, a state of excessive excitement;
• Headache;
• Vomit;
• Loss of sensation and immobilization of half of the body on the affected side.

Methods for diagnosing carotid thrombosis

Based on the patient's complaints, the doctor can only assume the presence of a blood clot, but to make a final diagnosis, the results of instrumental studies are required, such as:

Treatment Methods

To expand the channel and relieve spasm, novocaine blockade of sympathetic nodes or their removal is used.

Methods of surgical treatment of pathologies of the carotid artery

1. Excision of the arteriovenous shunt. In the surgical treatment of thrombosis of the external carotid artery, this technology is ineffective, since it is fraught with serious complications.
2. The method of carotid stenting is the restoration of vascular patency by deploying a stent (thin metal mesh). The most common, well-established technique.
3. Removal of a thrombosed or tortuous area and its replacement with a plastic material. The operation is associated with a risk of bleeding, a high probability of recurrence in the future (re-formation of a blood clot). For these reasons, the technique has not been widely adopted.
4. Creation of a new pathway for blood flow through an artificial shunt between the internal carotid and subclavian arteries.

Operations on the carotid artery are carried out in specialized surgical departments. The choice of method is determined by the attending physician, taking into account the condition, age, degree of damage to the carotid artery, damage to the patient's brain.

Video

The carotid artery is one of the large vessels of the musculo-elastic type, whose task is to nourish the organs of the head and neck. The work of the brain, eyes, tongue, thyroid and parathyroid glands depends on its blood flow.

Violation of patency leads to ischemia of brain regions with neurological symptoms. In recent years, a Doppler study of the branches of the carotid artery has been widely carried out for the purpose of early diagnosis of atherosclerosis.

Stenting of the carotid arteries allows you to fully restore the disturbed blood flow, the operation removes the obstacle, expands the lumen, saves a person from congenital and acquired diseases or delays their progression for a long time.

Structure and functions

The common carotid (carotid) artery is a steam room. This means that there are identical vessels on the left and on the right side. The left one starts from the aortic arch, and the right one starts from the brachiocephalic trunk. Heading vertically upwards, they bypass the chest and exit into the neck. Further, the course and structure do not differ, so we will consider the anatomical features using the example of one vessel.

The trunk goes under the sternocleidomastoid muscle next to the esophagus and trachea. Above the upper edge of the thyroid cartilage, it divides into the external carotid artery and the internal one. This place is called a bifurcation. Immediately after branching, the internal carotid artery forms a small expansion (carotid sinus). It is covered with numerous nerve cells and is an important reflex zone.

Here are receptor-analyzers, from here signals are given about the pressure inside the vessel, the chemical composition of the blood, the presence of oxygen. Nerve nodes regulate the work of the heart and blood vessels, maintain blood pressure, depending on the sufficiency of oxygen supplied with red blood cells. Therefore, massage of the sinus area is recommended for hypertensive patients as a means of self-reducing pressure during a crisis.

Features of the outer branch

The branches of the external carotid artery supply blood to:

• most of the face (muscles, scalp);
• language;
• roots of teeth;
• thyroid gland;
• part of the dura mater;
• eyeball.

One of the important functions is the possibility of reversed blood flow to assist the branches of the internal carotid artery and the vertebral artery in their narrowing. In such cases, blood through the anastomoses enters the basilar, and through the orbital branches - into the internal carotid.

Features of the internal branch

The internal branch of the carotid artery enters the skull through a special opening in the temporal bone. This arrangement is called intracranial. Its diameter is 10 mm. In the region of the base of the brain, together with the vertebral vessels (basal artery), through the anastomosis with the posterior cerebral arteries, it forms the circle of Willis. It is the main source of blood supply to the brain. Arteries depart from it deep into the convolutions, to the white and gray matter, the nuclei of the medulla oblongata and the cortical centers.

For vascular surgeons, it is important to know the exact site of damage to the vessel, so it is customary to isolate segments of the internal carotid artery:

• the cervical region is located in the deep layers under the muscles;
• the stony part - lies inside the bone canal, gives branches to the eardrum;
• a segment located inside a hole called "torn";
• cavernous area - passes between the sheets of the hard shell of the brain along the cavernous sinus, forms branches to the pituitary gland and membranes;
• the wedge-shaped part of the path is a very small segment in the subarachnoid space of the brain;
• eye (ophthalmic) area - goes along with the optic nerve, gives two branches (pituitary and ophthalmic arteries);
• communicative segment - located at the point of branching into the anterior cerebral and middle arteries, which go directly to the medulla.

The branches of the external artery come close to the muscles, it can be used to read the pulse

Features of localization and direction of the target blood flow of the common trunk, internal and branches of the external carotid arteries connect diseases of the carotid vessels with cerebrovascular insufficiency (general and internal branches) and pathology of the facial arteries (external branch). Therefore, it is more convenient to group diseases depending on the main feeding vessel.

Possible pathology of the external branch

The external carotid artery, unlike the internal one, is not directly responsible for the blood supply to the brain. Its good blood supply guarantees the opening of anastomoses with a lack of the circle of Willis associated with the pathology of the vertebral arteries or internal.

However, in maxillofacial, plastic, otolaryngological surgery, neurosurgical practice, diseases of the vessels of the external basin are of importance. These include:

• arteriovenous fistulas;
• hemangiomas of the face and neck;
• vascular malformations (angiodysplasia).

The causes are caused by a violation of the development of the fetus during pregnancy

Clinical symptoms may be absent. Provoked:

• injuries of the facial area;
• operations on the paranasal sinuses, with a curvature of the septum;
• extraction of teeth;
• medical procedures (puncture and sinus lavage);
• injections into the eye socket;
• hypertension.

The pathophysiological manifestation of this pathology is an arteriovenous shunt. Through it, arterial blood, which has greater pressure, goes through additional drainage routes into the venous system of the head. Such cases can be considered as one of the causes of venous congestion in the brain.

Up to 15% of all intracranial arteriovenous shunts are pathological connections with the sinuses of the dura mater (more often with the cavernous, transverse and sigmoid sinuses).

Angiodysplasias (in the American interpretation of "malformations") make up, according to various sources, from 5 to 14% of all vascular diseases. They are benign formations, formed by the growth of epithelial cells.

Hemangiomas in prevalence reach 1/5 among benign neoplasms of soft tissues. 60-80% of all hemangiomas are localized in the face area.

Symptoms are associated with:

• cosmetic defects;
• profuse hemorrhages, poorly amenable to conventional methods of stopping bleeding (nosebleeds);
• an additional sensation of a throbbing noise in the head at night, coinciding with the contractions of the heart.

Excessive bleeding during surgery can be fatal.

Possible pathology of the common and internal trunk

Chronic diseases such as atherosclerosis, tuberculosis, syphilis, fibromuscular dysplasia lead to significant changes in the carotid artery. A specific reason could be:

• inflammatory process;
• plaque localization;
• growth of the inner shell;
• dissection at a young age.

The mechanism of dissection means tearing the inner lining of the artery and the penetration of blood between the layers of the wall. A similar process is found in the branch of the internal carotid artery. The formed intramural hematoma forms an obstruction to the flow of blood.

Signs of dissection are detected by magnetic resonance angiography

The result of these mechanisms is always a narrowing (stenosis) of the diameter of the artery. As a result, the brain receives less oxygen, a clinical picture of tissue hypoxia, ischemic stroke develops.

Here we are interested in other types of changes:

• trifurcation;
• pathological tortuosity of the internal carotid artery;
• the formation of an aneurysm;
• thrombosis.

Trifurcation means division into three branches. It can be in two versions:

• anterior - internal carotid artery is divided into anterior, posterior cerebral and basilar;
• back - branches are made up of three cerebral arteries (anterior, middle and posterior).

Such an arrangement is not considered dangerous, but creates conditions for aneurysms and thrombosis.

How is the tortuosity of the carotid artery formed and manifested?

It became possible to detect tortuosity with the development of methods for studying vessels (angiography, angiotomography, dopplerography). The reasons for the formation of this pathology are still unclear, although the prevalence reaches 25% of the total population.

The most understandable explanations are:

• congenital changes;
• the consequences of increased stress on the arteries in hypertension, atherosclerosis.

In any case, the vessel becomes longer and forced to take on different forms:

• soft bends and turns at an obtuse angle - more often found by chance and do not have clinical symptoms until pronounced bends are formed that can compress the main vessel;
• kinking - the artery forms an acute angle with its direction;
• coiling - the vessel has the shape of a loop, the blood flow slows down significantly, there are symptoms of cerebral ischemia.

The last two forms are treated only surgically.

Why does an aneurysm form?

An aneurysm is an expansion of a section of an artery with a local thinning of the wall. A carotid aneurysm can be congenital in nature or form as a result of an inflammatory process, atrophy of the muscle layer and its replacement with thinned scar tissue.

Localized in the intracranial segments of the internal carotid artery. More often, a cerebral aneurysm has a saccular shape.

Unfortunately, the rupture of such a formation is more diagnosed by pathologists. It does not manifest itself in vivo, so patients do not go to the doctor.

The rupture of the thinned wall occurs when:

• head or neck injury;
• a sharp increase in blood pressure;
• physical or emotional stress.

The accumulation of blood in the subarachnoid space causes swelling and compression of the brain tissue. The consequences depend on the size of the hematoma, the speed of medical care.

An aneurysm must be distinguished from carotid chemodectoma, which is conditionally considered a benign formation, but in 5% of cases it degenerates into cancer. Growth begins in the bifurcation zone, and then spreads anteriorly to the submandibular region.

Chemodectoma pulsates on palpation, causes difficulty in swallowing, headaches

Thrombosis and its consequences

The main place for the formation of a thrombus inside the carotid artery is the bifurcation (bifurcation) into the internal and external branches. According to the laws of hydrodynamics, a lower speed and turbulence of the blood flow is created here. Therefore, there are the most favorable conditions for the deposition on the wall of platelets, their gluing, loss of fibrin threads.

Similar conditions contribute to the primary formation of an atherosclerotic plaque in the bifurcation zone, at the point of origin of the common carotid artery from the aortic arch. In the future, the detached part can become a mobile thrombus or embolus and go to the vessels of the brain with blood flow.

Contribute to thrombosis:

• increased blood clotting;
• low physical activity (sedentary life);
• antiphospholipid syndrome;
• traumatic brain injury;
• atrial fibrillation;
• heart defects;
• increased tortuosity of the arteries;
• congenital hypoplasia of the vessel walls;
• spasm caused by smoking.

The clinical manifestation depends on:

• the rate of thrombus formation;
• thrombus size;
• collateral states.

It is customary to distinguish between options for the course of thrombosis:

• asymptomatic;
• acute - a sudden violation of the blood supply to the brain, a high risk of death;
• subacute - there is a complete overlap of the carotid artery, at the same time there is a process of recanalization of the thrombus, so the symptoms either appear or disappear, last up to two days;
• chronic or pseudotumor - symptoms increase slowly over a month or more.

Additionally, a fast course (progredient) is considered with a thrombus continuously growing along the length and its penetration into the middle and anterior cerebral arteries.

Endarterectomy for thrombosis is associated with a risk of bleeding

With thrombosis at the level of the common trunk, the following symptoms can be observed:

• fainting and temporary loss of consciousness, if you try to give the patient a sitting position;
• paroxysmal intense headache and neck pain;
• complaints of specific tinnitus (caused by vibration of the carotid artery under the influence of blood flow);
• weakness in chewing muscles;
• visual disturbances.

Pathology of the blood supply to the eyes causes:

• atrophy of the optic nerve;
• development of cataracts;
• decreased vision during physical activity;
• temporary blindness in one or both eyes;
• deposition of pigment in the retina on the background of atrophy.

Thrombosis of the internal carotid artery in the area before entering the inside of the skull is accompanied by:

• severe headache;
• loss of sensation in the limbs;
• illegible speech (with left-sided lesion - loss of the ability to speak);
• transient disturbances in the sensation of one's own body in space;
• convulsions;
• mental changes (hallucinations, irritability, delirium);
• pain when checking sensitivity on the scalp from the side of the lesion.

The opto-pyramidal syndrome known in neurology is characteristic, including:

• decreased vision on one side;
• blurry fields of vision;
• loss of the lower or upper half in the field of view.

If thrombosis occurred in the intracranial section of the artery, then it manifests itself:

• a state of excitement, changing to a disturbed consciousness;
• headache accompanied by vomiting;
• loss of sensation and immobilization of half of the body.

Diagnostics

It is possible to suspect a disease by clinical symptoms, but it is impossible to make a correct diagnosis on this basis alone.

To diagnose the pathology of the carotid artery, modern methods are used:

• electroencephalography;
• ultrasound Doppler examination of the vessels of the neck and head;
• rheoencephalography;
• angiography with contrast injection;
• magnetic resonance angiography;
• CT scan.

Methods of treatment

Conservative methods of therapy are used for the initial manifestations of thrombosis, small aneurysms.

Patients are prescribed:

• drugs from the group of anticoagulants under the control of blood coagulability indicators (Heparin, Neodicumarin, Dicoumarin, Fenilin, Sinkumar);
• thrombolytics can be effective only in the first 4-6 hours after thrombosis (Urokinase, Fibrinolysin, Streptokinase, Plasmin, Streptodekaza).

To relieve spasm and expand the vascular bed, methods of novocaine blockade of the nearest sympathetic nodes or their removal are used.

In the treatment of pathology of the external carotid artery, the method of excision of the arteriovenous shunt, according to experts, is the least effective and more dangerous due to its complications.

Vascular surgeons consider endovascular injection of special embolizing materials combined with radiological exposure to be the most acceptable operation to block the accessory tract.

Carotid surgery is performed in specialized departments or centers. Most often, when narrowing of any kind, stenting of the carotid arteries is used. The stent in the form of a thin metal mesh unfolds and restores the patency of the vessel.

Removal of a tortuous or thrombosed area with replacement with a plastic material is used less frequently, since it is associated with a risk of bleeding and in the near future contributes to the re-formation of a blood clot.

An operation is used to create a bypass for blood flow through an artificial shunt between the subclavian and internal carotid arteries.

The choice of treatment method is determined by the doctor, taking into account the age of the patient, the degree of narrowing and severity of the pathology of the carotid artery, brain damage. The decision is made after careful consideration.

Normal human anatomy: lecture notes M. V. Yakovlev

6. BRANCHES OF THE INTERNAL CAROTID ARTERY

internal carotid artery(a. carotis interna) provides blood supply to the brain and organs of vision. The following parts are distinguished in it: cervical (pars cervicalis), stony (pars petrosa), cavernous (pars cavernosa) and cerebral (pars cerebralis). The cerebral part of the artery gives off the ophthalmic artery and divides into its terminal branches (anterior and middle cerebral arteries) at the inner edge of the anterior clinoid process.

Branches of the ophthalmic artery(a. ophthalmica):

1) central retinal artery (a. centralis retinae);

2) lacrimal artery (a. lacrimalis);

3) posterior ethmoid artery (a. ethmoidalis posterior);

4) anterior ethmoid artery (a. ethmoidalis anterior);

5) long and short posterior ciliary arteries (aa. ciliares posteriores longae et breves);

6) anterior ciliary arteries (aa. ciliares anteriores);

7) muscular arteries (aa. musculares);

8) medial arteries of the eyelids (aa. palpebrales mediales); anastomose with the lateral arteries of the eyelids, form the arch of the upper eyelid and the arch of the lower eyelid;

9) supratrochlear artery (a. supratrochlearis);

10) dorsal artery of the nose (a. dorsalis nasi).

AT middle cerebral artery(a. cerebri media) distinguish wedge-shaped (pars sphenoidalis) and insular parts (pars insularis), the latter continues into the cortical part (pars corticalis).

Anterior cerebral artery(a. cerebri anterior) connects to the artery of the same name on the opposite side through the anterior communicating artery (a. communicans anterior).

Posterior communicating artery(a. communicans posterior) is one of the anastomoses between the branches of the internal and external carotid arteries.

Anterior villous artery(a choroidea anterior).

Circulation of current internal qi (internal energy) and purification of meridians and collaterals It is the normal and natural function of the human body that internal qi flows through the meridians and collaterals. When meridians and collaterals in the human body