The left common carotid artery is longer (from the aortic arch)

The right common carotid artery is shorter (from the brachiocephalic trunk)

Common carotid artery - level of the upper edge of thyroid cartilage - internal carotid artery (no branches before entering the skull) - external carotid artery (several branches)

Clinically, it is often used as a site for feeling the pulse and temporarily applying pressure to stop bleeding. Whether there are branches is an important sign to distinguish the internal carotid artery from the external carotid artery during neck surgery.

1. Superior thyroid artery: slightly below the greater angle of the hyoid bone, it emits the sternocleidomastoid muscle branch, the infrahyoid muscle branch, and the cricothyroid muscle on the way to serve the infrahyoid muscle group and its nearby skin. It is the subhyoid muscle skin used clinically. The source of blood supply to the valve. Clinically, regional chemotherapy with retrograde cannulation of the external carotid artery can be performed at the origin of the superior thyroid artery; external carotid artery ligation is performed between this artery and the lingual artery. Therefore, the origin of the superior thyroid artery is a commonly used anatomical landmark.

2. Ascending pharyngeal artery: It branches from the medial wall of the origin of the carotid artery, goes up along the lateral wall of the pharynx to the base of the skull, and branches to the pharynx, soft palate, palatine tonsils and deep cervical muscles.

3. Lingual artery: The tip of the greater corner of the hyoid bone is a landmark for finding the origin of the lingual artery or the external carotid artery. The lingual artery is divided into three segments:

4. Facial artery: slightly above the greater angle of the hyoid bone, at the lower edge of the posterior belly of the digastric muscle. Its branches are:

5. Occipital artery: It originates from the posterior outer wall of the external carotid artery at the same height as the facial artery. Clinically, when making the sternocleidomastoid myocutaneous flap with the muscle pedicle located above, attention should be paid to the relationship between the course of the above-mentioned arteries and the anastomotic branches to avoid damage to the occipital artery and its branches to ensure the blood supply of the myocutaneous flap.

6. Posterior auricular artery: In the posterior mandibular fossa, between the posterior belly of the digastric muscle and the upper edge of the stylohyoid muscle, it originates from the posterior wall of the external carotid artery, runs backward and upward along the upper edge of the stylohyoid muscle in the deep surface of the parotid gland. It passes through the superficial surface of the main trunk of the facial nerve to between the cartilage and mastoid of the external auditory canal, and is distributed to the muscles and skin at the back of the auricle. The posterior auricular artery anastomoses with both the occipital artery and the superficial temporal artery. Postauricular axial flap is often designed clinically with this artery as the pedicle.

7. Maxillary artery: also called internal maxillary artery

8. Superficial temporal artery

The internal carotid artery nourishes the brain, orbital structures and the main frontonasal arteries. It originates from the common carotid artery in the carotid triangle, goes up along the pharyngeal side wall to the base of the skull, and penetrates the carotid canal in the petrous part of the temporal bone to enter the cranial cavity.

1. Vertebral artery: usually passes through the transverse process foramen of the sixth to first cervical vertebrae, enters the cranial cavity through the foramen magnum, and merges into a basilar artery, which branches to supply the brain and spinal cord. Its end is divided into the left and right posterior cerebral arteries and participates in the cerebral arterial ring. composition.

2.Thyrocervical trunk

3. Costocervical trunk: It originates from the second segment of the subclavian artery, and its branched deep cervical artery branches to the deep part of the neck and anastomoses with the branch of the occipital artery.

Features: 1. Extensive arterial anastomoses in the head and neck provide sufficient blood supply, which is conducive to wound healing and the success of plastic surgery. 2. When performing a large-scale operation, in order to prevent excessive bleeding, although the relevant main artery is ligated, the arterial anastomosis can still be performed without affecting the local blood supply. 3. However, due to the abundant arterial anastomoses, it is also a disadvantageous factor for excessive bleeding during oral, maxillofacial and neck injuries or surgery. At the same time, in the case of massive bleeding in the oral, maxillofacial and neck areas, even if the main blood supply artery on the injured side is compressed or ligated, sometimes the bleeding cannot be completely stopped.

1. Facial vein: It starts from the medial canthal vein and ends at the submandibular triangle, then passes through the submandibular gland, the posterior belly of the digastric muscle and the superficial surface of the stylohyoid muscle, at the posterior and inferior aspects of the mandibular angle and the mandibular surface from the posterior and superior aspects. The anterior branch of the posterior vein merges into the common facial vein, which empties into the internal jugular vein near the greater angle of the hyoid bone. The triangle formed by the root of the nose and the corners of the mouth on both sides is called the facial dangerous triangle.

2. Superficial temporal vein: A venous network that starts in the scalp and is formed by the confluence of the frontal and parietal branches above the zygomatic arch. It penetrates the parotid gland superficially at the root of the zygomatic arch. Clinically, when forming a forehead flap, care should be taken to avoid damaging the superficial temporal vein and its communicating vein branches, so as to avoid obstruction of the venous blood returning from the flap and causing necrosis.

Mainly include: pterygoid venous plexus, maxillary venous plexus, retromandibular vein and common facial vein, which are deeply located.

1. Pterygoid venous plexus: located in the infratemporal fossa, equivalent to the posterior and superior part of the maxillary tubercle, distributed between the temporalis muscle and the medial and lateral pterygoid muscles. This venous plexus converges backward to form the maxillary vein. When performing maxillary retroalveolar nerve block anesthesia, the direction, angle, and depth of the injection needle should be correctly controlled to avoid puncturing the pterygoid venous plexus and causing hematoma. Anteriorly: Deep Facial Vein Posteriorly and Laterally: Maxillary Vein Upward: Through the rupture of the foramen ovale network leading to the connection of the blood vessels to the intracranial cavernous sinus along the vein.

2. Maxillary vein: It starts from the posterior end of the pterygoid plexus and joins the retromandibular vein near the posterior edge of the mandibular ramus.

3. Retromandibular vein: After the retromandibular vein leaves the lower end of the parotid gland, the marginal mandibular branch of the facial nerve crosses its superficial surface. Therefore, the retromandibular vein can be used to find the marginal mandibular branch and then trace the facial nerve trunk.

4. Common facial vein: It is a thick venous trunk at one end, located within the carotid triangle, behind and below the angle of the mandible.

1. External jugular vein: It is a large superficial vein in the neck. Its location is superficial. Most of it is located in the superficial fascia and on the surface of the sternocleidomastoid muscle. This vein is composed of two front and rear branches. The front branch is the retromandibular vein. The posterior branch is synthesized by the occipital vein and the postauricular vein. The anterior and posterior branches meet near the angle of the mandible, travel downward and posteriorly along the surface of the sternocleidomastoid muscle, to the posterior edge of the muscle, about 2.5cm above the midpoint of the clavicle, pass through the superficial to deep layers of the deep cervical fascia, and merge into The subclavian vein occasionally merges into the internal jugular vein. The external jugular vein collects venous blood from the skin and muscles of the occiput and lateral neck.

2. Anterior jugular vein: A superficial vein that originates from the submental part, descends along both sides of the anterior midline of the neck, turns outward at a right angle near the lower part of the neck, and empties into the terminal part of the external jugular vein, and occasionally into the subclavian vein or brachiocephalic vein. Clinically, the external jugular and anterior jugular veins are often used as anastomotic veins for free tissue flaps to repair oral and maxillofacial defects.

1. Internal jugular vein: a thick venous trunk in the head and neck, which is the main vein for the return of blood vessels in the head, face and neck. It starts from the dorsal side of the internal carotid artery, adjacent to the lateral wall of the pharynx, then descends along the lateral side of the common carotid artery, and is wrapped in the cervical sheath together with the vagus nerve. The veins merge to form the brachiocephalic vein. The lower end of the internal jugular vein also expands to form the subjugular bulb. There is a pair of valves above and sometimes below the expanded cavity. These valves prevent blood from flowing backward.

2. Subclavian vein: Located at the base of the neck, it is the continuation of the axillary vein. It starts from the lateral edge of the first rib, behind the sternoclavicular joint and the medial edge of the anterior scalene muscle, and merges with the internal jugular vein to form the brachiocephalic vein.

1.Conduit vessel

2. Barrier vein

3. Venous network around cranial nerves and blood vessels

4.Ocular vein