Scalp and Face Anatomy PDF

Scalp and face lec. 2&3 Dr. Eman Ghanim  Objective of the lec. A- to describe the layer of the scalp B- to discuss the innervation and blood supply of the scalp and face To know the function of facial expression muscles To discus venous drainage of face  Th...

Scalp and face lec. 2&3 Dr. Eman Ghanim  Objective of the lec. A- to describe the layer of the scalp B- to discuss the innervation and blood supply of the scalp and face To know the function of facial expression muscles To discus venous drainage of face  The scalp consists of five e layers, the first three of which are intimately bound together and move as a unit 1-skin, which is thin and hair bearing and contains numerous sebaceous glands 2-connective tissue beneath the skin, dense collagen fibers contain blood vessels and nerves, the collagen fibers adhere to the wall of the blood vessels so prevent the vessels from contraction during injury. Numerous arteries and veins are found in this layer. The arteries are branches of the external and internal carotid arteries, and a free anastomosis takes place between them. 3-aponeurosis (epicranial), which is a thin tendinous sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle. The lateral margins of the aponeurosis are attached to the temporal fascia. The subaponeurotic space is the potential space beneath the epicranial aponeurosis 4-Loose areolar tissue, which occupies the subaponeurotic space. The areolar tissue contains a few small arteries but it also contains some important emissary veins. emissary veins are valveless and connect the superficial veins of the scalp with the intracranial venous sinuses 5-Pericranium, which is the periosteum covering the outer surface of the skull bones. it is firmly adherent to the sutures Scalp structure 1-S= Skin 2- C= Connective tissue 3-A= Epicranial aponeurosis 4-L= Loose areolar tissue 5-P= Periosteum  Muscles of the Scalp Occipito-frontalis: consist of two pairs of bellies (2 occipital and 2 frontal bellies) connected with each other by aponeurosis. Occipital bellies originate from highest nuchal line of occipital bone then it inserted to aponeurosis. frontal bellies originate from the aponeurosis and inserted to the skin of eye brows. it has no bony attachment The muscle is innervated by facial nerve (posterior auricular branch to occipitalis & temporal branch to frontalis) action : rises the eye brow and wrinkles the forhead Muscles of the Scalp  Nerves of the scalp: A-anterior to the pinna of the ear:- is by the branches of trigeminal nerve which are:- 1-From Ophthalmic division : Supratrochlear n.; supplies the middle of the forehead up to the hairline. Supra-orbital n.; supplies the lateral part of the forehead And the scalp up to the vertex. 2- Maxillary division: Zygomatico-temporal n 3- Mandibular division: Auriculotemporal n ,It supplies the upper half of the auricle externally, parotid gland & the skin over the temporal regoin. B- posterior to pinna of the ear , supplied by Posterior rami of C2 (greater occipital n) supply the back of the scalp up to the vertex. The lesser occipital nerve, a branch of ventral ramus C2 supplies the scalp over the lateral part of the occipital regoin Nerves and artery of the scalp:-  Blood supply Has a rich blood supply from internal and external carotid arteries, the scalp is an area for anastomosis between the branches of external carotid artery and internal carotid artery. From the internal carotid artery *supraorbital artery: emerges from supraorbital notch or foramen. *supratrochlear artery: emerges from medial angle of orbit. From the external carotid artery *superficial temporal artery:It is one of the two terminal branches of external carotid artery. it run ant. to the auricle with auriculotemporal n *post. auricular artery:- it run post. to the auricle. *occipital artery  Applied anatomy: sebaceous cysts  Wounds of the scalp has 2 character  Open widely, due to the stretch effect of the aponeurosis  Bleeds profusely, because the scalp is rich in blood vessels which lie in the second layer and adherent of collagen fiber to the wall of the vessels.  The skin of the scalp possesses numerous sebaceous glands, the ducts of which are prone to infection and damage by combs. For this reason, sebaceous cysts of the scalp are common  Face No deep fascia is present in the face except around the parotid gland and over the buccinator m. Muscles of the Face (Muscles of Facial Expression) Orbicularis oculi muscle: is a broad, flat muscle that encircles the orbit. It divided into three portions: - orbital part (closes the eyelids forcibly ) - palpebral part; (gently closes the eyelid, for example when blinking - lacrimal part.(aid in tear drainage by compressing the lacrimal sac Nerve supply: facial nerve  Orbicularis oris muscle: circular muscle around the mouth Action: it compresses lips together Nerve supply: facial nerve ✔ Buccinator muscle, Action: compresses the cheeks against the teeth, Nerve supply: facial nerve its paralysis tend to accumulate food in the vestibule of the mouth It is pierced by  the parotid duct to which it gives a sphincter-like action  The buccal branch of mandibular nerve is sensory to the muscle & ends in the skin overlying it Muscles of Facial Expression also include occipitofrontalis and platysma m  Nerves of the face 1-MOTOR : The facial muscles are innervated by the facial nerve 2-SENSORY: 1 ) By trigeminal nerve (5th cranial nerve). Terminal branches of the three divisions of trigeminal nerve supply the face as follow: I: Ophthalmic division:  Supraorbital n  Supratrochlear n  Infratrochlear n  Lacrimal n  External nasal n Maxillary division  Infraorbital nerve:- it is terminal branch of maxillary nerve emerge through the infraorbital foramen supplies the skin and mucus membrane of the upper lip, lower eyelid and the skin between them and the side of the nose through labial, palpebral and nasal branches respectively  Zygomaticofacial nerve:- passes through Zygomaticofacial foramen in the zygomatic bone, it supplies the skin over the bony part of the cheek.  Zygomaticotemporal nerve:- it pierce the zygomatic bone and supplies the skin over the anterior part of the temple. III: Mandibular division: Buccal n.: skin over buccinators Mental n.: chin & lower lip Auriculotemporal n. 2 ) Great auricular nerve arises from the cervical plexus Supplies skin of the auricle, as well as the area overlying the parotid gland and mastoid process. Nerves of the face MOTOR NERVE Facial nerve  Arteries of the face Arteries of the face: Arteries of the face lie in the subcutaneous tissue. The main artery of the face is the 1- facial artery it arises from the ant. aspect of the ECA leaving it deep to the posterior belly of digastric muscle & passes in the submandibular triangle to reach the lower border of the mandible where it curves up to the face just anterior to the masseter muscle lateral to the angle of the mouth. The artery ascends in a very tortuous course towards the medial angle of the eye to terminate by becoming angular artery which anastomosis with dorsal nasal branch of ophthalmic artery. in the face gives the following branches:- a.Inf. Labial a. : to the lower lip b.Sup. Labial a. : to the upper lip c.Lateral nasal a. d.Angular a. Facial artery in the neck gives the following branches: a.Tonsillar branch:- which run upward to the tonsils b.Glandular branch: to the submandibular salivary gland c.Ascending palatine artery: to the soft palate d.Submental artery: run on the margin of mandible to enter submental triangle 2- ophthalmic artery gives supraorbital, supratochlear and dorsal nasal 3- maxillary artery gives a- Infraorbital artery: One of the terminal branches of maxillary artery. Leaves the infraorbital foramen and supply the area below the orbit b- buccal supply the cheek c-mental art. Supply the chin Appears in the face from the mental foramen 4-Transverse facial artery. is a branch of the superficial temporal artery  Venous Drainage of the Face The facial vein receives tributaries corresponding to the branches of the facial artery, it is joined to pterygoid venous plexus by the deep facial vein and to the cavernous sinus by the superior ophthalmic vein  Lymphatic drainage of the face;-  The forehead and anterior part of the face drain to the submandibular lymph nodes.  Lateral part of the face drains to pre-auricular lymph nodes.  The chin, central part of the face, and the lower lip drain to submental lymph nodes