In My Head
Anatomically, the face stretches from the point of the chin to the roots of hair. The skin of the face is quite pliable and loose. Owing to the face's lack of deep fascia, facial wounds tend to bleed rather freely.
There are five orifices on the face: two for the eyes, two nostrills, and the mouth.
The blood supply to the face and indeed the most of the scalp comes mainly from the external carotid artery.
The sensory supply to the face comes solely from the trigeminal nerve (the fifth cranial nerve), so named because it branches into three divisions. The ophthalmic division covers an area above the eyes, including the forehead and most of the nose. The maxillary division covers an area below the eyes but above the mouth, including the cheeks and some of the nose. The mandibular division covers an area below the mouth and to the sides of the cheeks to the ears. This area does not cover the mandibular angle (the protrusion on the jawbone), which is innervated by the second cervical spinal nerve.
The muscles in the face include the nasal muscles, zygomatic muscles, muscles of mastication (chewing), and those of facial expression. The frontal part of the large occipitofrontalis muscle contains two parts, the occipital part (or occipitalis) and the frontal part (or frontalis). Although the two muscles are separate and supplied by different nerves, they are connected by fibromuscular tissue (called the galea aponeurotica) that stretches across the top half of the head to form the scalp. This arrangement of two different muscles attached together constitutes a digastric muscle, the actions of which are to wrinkle the forehead and raise the eyebrow. The muscle is attached to the skin of the forehead and eyebrow in front (anteriorly) and to the superior nuchal line in back (posteriorly). The frontal belly of the digastric muscle is supplied by the temporal nerve, a branch of the facial nerve (the seventh cranial nerve) while the occipital belly is supplied by another branch of the facial nerve, the posterior auricular nerve.