The paired facial artery arises as the third major branch of the external carotid artery and supplies large portions of the surface structures of the face, including the nose, lips, and tongue. The facial artery takes a conspicuously tortuous course and exhibits multiple branches to supply the entire area with oxygenated blood from the pulmonary circulation.
What is the facial artery?
The facial artery, also named as facial artery or facial artery, originates as the third main branch of the external carotid artery and shows a multiple tortuous course with several branches in the face and neck area to be able to supply almost the entire surface area of the face and part of the neck as well as the palatine tonsils with oxygen-rich blood. The facial artery ends at the inner corner of the eye in the form of the angular artery. In terms of the structure of its vascular wall, the facial artery belongs to the transitional forms from the elastic to the muscular type. This means that it plays a role in smoothing arterial blood flow as well as in regulating systolic blood pressure through stress hormones secreted by the sympathetic nervous system. The smooth muscle in the walls of the artery responds to the hormones by contracting, causing the vessel to narrow and blood pressure to rise.
Anatomy and structure
The facial artery, which originates at the level of the mandible of the external carotid artery, runs a short distance along the underside of the mandible and then swings upward and passes laterally of the nose to the inner corner of the eye, where it terminates as the angular artery and joins the capillary system. From the facial artery branch the ascending palatine artery (arteria palatina ascendens), the submental artery (arteria submentalis), the lower labial artery (arteria labialis superior/inferior), and the terminal branch, the ocular angular artery (arteria angularis). Strikingly, a side branch of the facial artery forms anastomoses with a branch of the higher maxillary artery. This means that there is a direct connection between two arterial branches, so that if one fails, the other vessel can act as a back-up. The facial artery corresponds to the mixed arterial type, the transitional form from the large, elastic, cardiac artery like the aorta to the muscular type. This means that its middle vessel wall, the tunica media or media, contains both elastic fibers and annular and helical smooth muscle cells. While the elastic fibers respond passively to an increase in blood pressure by stretching and enlarging the lumen of the vessel, the smooth muscle cells respond to stress hormones. They cause the muscle cells to contract, constricting the vessel and increasing blood pressure accordingly.
Function and tasks
One of the main functions and tasks of the facial artery is to supply oxygenated blood to the surface structures of the face. The facial artery performs this function and task through its branching vessels. Specifically, the ascending palatine artery supplies the pharynx and the submental artery supplies the mandibular salivary glands along with adjacent structures. The inferior and superior labial arteries supply the lower and upper lips, and the terminal branch, the angular artery, is directed to supply the nose and the structures in the inner corner of the eye. As a mixed type, the facial artery embodies the transition from a large, cardiac elastic artery to a muscular type. This means that the facial artery makes a small contribution to the passive Windkessel function of elastic vessels, but also plays a part in the active narrowing or widening of the lumen because of the smooth muscle cells in its middle vessel wall, the media. During ventricular systole, the Windkessel function leads to a smoothing of the blood pressure peak by dilating the vascular lumen and to a steadying of the blood flow. During diastole, the relaxation phase of the ventricles, the vessel walls contract again and thus maintain the necessary residual pressure (diastolic pressure). However, the smooth muscle cells in the media are also able to respond to stress hormones by contracting. This results in a constriction of the vessels with the effect of an increase in blood pressure.The mechanism involving the facial artery has importance in stressful situations and changing performance demands due to physical or mental exertion.
Diseases
Potential diseases and conditions that may affect the facial artery are similar to those known to affect other arteries. The most common problems result from narrowing (stenosis) of the lumen of the facial artery. This results in a reduced supply to the downstream supply areas. The only exception is the terminal branch of the facial artery, which is directly connected to the inferior alveolar artery, a side branch of the maxillary artery, so that in the event of partial failure of the facial artery, the inferior alveolar artery can take over the supply “from the other side”. Stenoses are usually caused by arteriosclerosis, in which deposits called plaques form in the media, sclerotizing the vessel at the site and protruding into the lumen, resulting in the narrowing. Narrowings can also form as a result of local inflammation in the vessels, for example, as an effect of an immune response to an infection. In some cases, blood clots (thrombi) can form at the site of inflammation, leading to thrombosis, an occlusion of the vessel. In rare cases, thrombi can be carried along with the bloodstream and become lodged in a smaller artery, causing an embolism with sometimes far-reaching consequences. Outpouchings, or aneurysms, are extremely rare in the facial artery and relatively easy to identify because the vascular network of the facial artery is usually located on the surface of the face and potential bleeding would also usually be easily accessible.
