Notes
Arteries of the Head and Neck (Advanced)
Sections
Arteries of the Head and Neck
Brachiocephalic trunk
- First branch of arch of aorta
Bifurcates to form the right common carotid and Right subclavian arteries
Left common carotid artery
- Second branch of arch of aorta
Left subclavian artery
- Third branch of arch of aorta
Common carotid artery
Bifurcates:
- Internal carotid artery enters the skull via the carotid canal (and is addressed with the blood supply of the brain)
- External carotid artery travels posterior to the mandible, then divides into its two terminal branches.
Branches of External Carotid Artery:
– Superior thyroid artery travels to the superior portion of the thyroid gland;
– Ascending pharyngeal artery arises from the posterior aspect of the external carotid artery and travels superiorly (aka, ascends) through the neck to supply structures related to the throat; - Lingual artery arises just superior to the ascending pharyngeal artery, and travels deep to the mandible to reach its target tissues in the mouth.
- Facial artery courses deep to the mandible initially, but then emerges to travel superiorly over the face towards the orbits.
Facial artery has several branches:
– Inferior labial and superior labial arteries, which travel to the upper and lower lips.
– Lateral nasal artery, which travels to the lateral and dorsal sides of the nose.
– Angular artery, which is the terminal branch of the facial artery; it extends towards the medial corner of the eye. - Occipital artery arises posteriorly and travels deep to the mastoid process to the back of the head.
- Posterior auricular artery passes superiorly behind the external auditory meatus.
- External carotid artery terminates where it becomes the:
– Maxillary artery, which dives into the infratemporal fossa and gives rise to several branches that serve the head.
– Superficial temporal artery, which gives rise to the transverse facial artery, which supplies the superficial structures of the face. - Superficial temporal artery splits to form the:
– Anterior and posterior superficial temporal arteries, which anastomose with each other and the occipital artery.
Subclavian artery
Four branches:
- Vertebral artery passes through the transverse foramina of cervical vertebrae 6 through 1 (it passes over the transverse foramen of C7), and into the cranium via the foramen magnum (this vessel can be subdivided into cervical, vertebral, suboccipital, and cranial portions, according to region).
- Thyrocervical trunk gives rise to three branches (the inferior thyroid, transverse cervical, and suprascapular arteries).
- Internal thoracic artery
Descends within the anterior thorax, where it gives rise to the anterior intercostal arteries. - Costocervical trunk
Gives rise to two branches (the deep cervical and supreme (aka, superior) intercostal arteries).
Additional Information
Carotid body
- Lies at bifurcation of common carotid artery
- Monitors blood oxygen levels
Carotid sinus
- Dilation in internal carotid artery
- Monitors blood pressure
Clinical Correlations
- Temporal arteritis
- Cartoid & Vertebral Artery Dissections
- Occlusion of the proximal subclavian artery can cause subclavian steal syndrome
- The subclavian artery "steals" blood flow from the vertebral artery to supply the arm.
- Decreased blood-flow through the vertebral artery, which supplies the posterior circulation of the brain: the brainstem and posterior brain, can result in a myriad of symptoms, including syncope.
- Blockage of the carotid arteries can obstruct blood flow and lead to stroke, because the internal carotid arteries supply the anterior blood-flow circulation to the brain.
- Learn more about atherosclerosis.
- Moyamoya, a progressive cerebrovascular disorder that primarily affects children, causes narrowing of the internal carotid arteries and ischemic attack.
- Its name (which means, "puff of smoke" in Japanese) is derived from the tangle of tiny vessels that form in the brain to compensate for blockages.
- Surgical fixes of internal carotid artery blockage include EC-IC (extracranial-intracranial) bypass, in which the superficial temporal artery is rerouted through a hole in the cranium and connected to the internal vasculature, which opens up blood flow to the brain.
Full-Length Text
Here we will draw the arteries that arise from the common carotid and subclavian arteries, with a special focus on the branches of the external carotid artery (the branches of the internal carotid artery that supply the brain are addressed elsewhere).
Start a table.
Generate the following arterial tree, for key arteries that supply the head and neck:
Brachiocephalic trunk divides into the:
- Subclavian artery, which branches into the vertebral artery and 3 other vessels.
- Common carotid artery, which branches into the: internal carotid artery, and, the external carotid artery, which terminates as the: maxillary artery and superficial temporal artery.
Before we learn the arteries, themselves, in order to understand the important anatomical landmarks, let's review the bony features of the head in lateral view.
Draw the cranium, outline the anterior face: show the nasal bones and the maxilla, the zygomatic arch and bone, and, the eye orbit.
Draw the mastoid process (of the temporal bone), and, just anterior to it, the show the external auditory meatus.
Draw the mandible.
Indicate the infratemporal fossa, which is an irregularly shaped area inferior to the zygomatic arch and deep to the mandible.
Now we'll redraw the right side of the skull with the arteries.
Again, redraw the bony landmarks.
Next, add the 7 cervical vertebrae.
Include their transverse foramina.
Anteriorly, in the neck, draw the trachea and larynx.
Show that the thyroid gland lies superficial to the trachea and larynx.
Now, let's draw the arteries:
Begin with the brachiocephalic trunk, which is the first branch of the arch of the aorta.
Show that the brachiocephalic trunk bifurcates to form the: right common carotid artery, and, the right subclavian artery. Recall that, on the left side, the common carotid and subclavian arteries arise separately from the arch of the aorta.
Now, show that the right subclavian artery gives rise to four branches before it becomes the axillary artery:
- The vertebral artery, which passes through the transverse foramina of cervical vertebrae 6 through 1 (it passes over the transverse foramen of C7), and into the cranium via the foramen magnum (this vessel can be subdivided into cervical, vertebral, suboccipital, and cranial portions, according to region).
- The thyrocervical trunk, which gives rise to three branches (the inferior thyroid, transverse cervical, and suprascapular arteries).
- The internal thoracic artery, which descends within the anterior thorax, where it gives rise to the anterior intercostal arteries.
- The costocervical trunk, which divides into two branches (the deep cervical and supreme (aka, superior) intercostal arteries).
Now, return to the right common carotid artery, and show that it bifurcates at the superior edge of the thyroid cartilage of the larynx to form the:
- Right internal carotid artery, which enters the skull via the carotid canal (and is addressed with the blood supply of the brain).
- The right external carotid artery, which travels posterior to the mandible, then divides into its two terminal branches.
At the bifurcation of the common carotid artery, indicate the location of the carotid body, which monitors blood oxygen levels.
Nearby, show the location of the carotid sinus; this dilation in the internal carotid artery houses receptors that monitor blood pressure (aka, baroreceptors).
Although you can easily palpate the common carotid artery pulse; be aware that such external pressure can induce fainting in individuals with hypersensitive carotid sinuses.
Next, from inferior to superior, let's show the branches of the external carotid artery; notice that they are generally named for their target tissues and/or regions.
First, show the superior thyroid artery, which, as its name implies, travels to the superior portion of the thyroid gland.
Next, show that the ascending pharyngeal artery arises from the posterior aspect of the external carotid artery and travels superiorly (aka, ascends) through the neck; this small vessel supplies structures related to the throat.
Show that the lingual artery arises just superior to the ascending pharyngeal artery, and travels deep to the mandible to reach its target tissues in the mouth.
Show that the facial artery courses deep to the mandible initially, but then emerges to travel superiorly over the face towards the orbits.
Near the origin of the facial artery, show that the occipital artery arises posteriorly and travels deep to the mastoid process to the back of the head.
Then, show that the posterior auricular artery passes superiorly behind the external auditory meatus.
Where thee external carotid artery terminates, show that it splits to form the:
Maxillary artery, which dives into the infratemporal fossa and gives rise to several branches that serve the head, and, the superficial temporal artery.
The superficial temporal artery gives rise to the transverse facial artery, which, with the facial artery, supplies the superficial structures of the face.
Superiorly, show that the superficial temporal artery splits to form the anterior and posterior superficial temporal arteries, which anastomose with each other and the occipital artery.
Branches from the maxillary artery and internal carotid artery also supply superficial structures of the face; the branches of these vessels are discussed in depth elsewhere.
It's important to recognize that individuals display variation in arterial branching patterns, and anastomoses are common. However, blockage of arteries in the head and neck can have serious consequences.
Start a table to note some clinically important points:
Occlusion of the proximal subclavian artery can cause subclavian steal syndrome, in which the subclavian artery "steals" blood flow from the vertebral artery to supply the arm. Decreased blood-flow through the vertebral artery, which supplies the posterior circulation of the brain: the brainstem and posterior brain, can result in a myriad of symptoms, including syncope.
Blockage of the carotid arteries can obstruct blood flow and lead to stroke, because the internal carotid arteries supply the anterior blood-flow circulation to the brain.
Moyamoya, a progressive cerebrovascular disorder that primarily affects children, causes narrowing of the internal carotid arteries and ischemic attack; its name (which means, "puff of smoke" in Japanese) is derived from the tangle of tiny vessels that form in the brain to compensate for blockages.
Surgical fixes of internal carotid artery blockage include EC-IC (extracranial-intracranial) bypass, in which the superficial temporal artery is rerouted through a hole in the cranium and connected to the internal vasculature, which opens up blood flow to the brain.
END OF ESSENTIAL/START OF ADVANCED
Now let's draw the branches of the facial artery, from inferior to superior:
Inferior labial and superior labial arteries, which travel to the upper and lower lips;
The lateral nasal artery, which travels to the lateral and dorsal sides of the nose, and,
The angular artery, which is the terminal branch of the facial artery; it extends towards the medial corner of the eye.