Head & Neck Anatomy

The Trigeminal nerve( Fifth Or Trifacial Nerve) The  trigeminal nerve  is the largest cranial nerve and is the great sensory nerve of the head and face, and the motor nerve of the muscles of mastication.   It emerges from the side of the pons, near its upper border, by a small  motor  and a large  sensory root. Sensory :  The three terminal branches of CN V innervate the skin, mucous membranes and sinuses of the face. Their distribution pattern is similar to the dermatome supply of spinal nerves (except there is little overlap in the supply of the divisions). Motor : Only the mandibular branch of CN V has motor fibres. It innervates the muscles of mastication: medial pterygoid, lateral pterygoid, masseter and temporalis. The mandibular nerve also supplies other 1st pharyngeal arch derivatives: anterior belly of digastric, mylohyoid, tensor veli palatini and tensor tympani. Parasympathetic Supply : The post-ganglionic neurones of parasympathetic ganglia travel with b

Occipitofrontalis muscle: Form and shape : I t consists of two frontal bellies and two occipital bellies connected by an epicranial aposeurosis. T he 2 frontal bellies are broader and longer than two occipital bellies. T he 2 frontal bellies come close together in the median plane . O n the other hane th 2 occipital bellies are separated by the epicranial aponeurosis. Attachment: Each frontal belly: /A rises from the skin and super facial fascia of the eye brow and the forehead. The medial fibers of the frontal bellies are continuous of those of  procerus muscle. The intermediate and the lateral fibers blend with corrugator spercilli and the orbital part of orbicularis oculi muscles. Inserted posteriorly into the epicranial aponeurosis. Each occipital belly: Arises from the highest nuchal line. Inserted Into the epicranial aponeurosis anteriorly Nerve supply The frontal belly : by the temporal branches of the facial nerve The occipital belly :

SCALP The scalp represents the soft tissue covering the scull cap. Extension It extends from the eye brow infront the superior nuchal line behind and between the temporal lines of both sides. Layers of the scalp: 1- S kin. 2- c onnective subcutaneous tissue(superfacial fascia):    consists of dense fibrous tissue     The dense nature of the fascia is responsible for the following:      it doesn't allow any fluid accumulation.      acut wound in it does not gap unless it involves the underlying aponeurosis. It is adherent to the overlying and the underlying layers. It contains the vessels and nerves of the scalp. The walls of the vessels and nerves of the scalp. The walls of vessels are firmly attached to the tissues so a cut vessel in it cannot       retract and leads to profuse bleeding. 3- A poneurosis of the occipitofrontalis muscle     The muscle consists of two frontal and two occipital bellies connected together by the epicranial aponeurosis