SCALP AND FACE LECTURE.pdf

GROSS ANATOMY OF ANATOMY OF SCALP AND FACE BY DR KELECHI DURUH DEPARTMENT OF ANATOMY FBMS UNEC 6TH MAY 2024 1 OUTLINE FOR SCALP INTRODUCTION LAYERS OF SCALP MUSCLES OF S...

GROSS ANATOMY OF ANATOMY OF SCALP AND FACE BY DR KELECHI DURUH DEPARTMENT OF ANATOMY FBMS UNEC 6TH MAY 2024 1 OUTLINE FOR SCALP INTRODUCTION LAYERS OF SCALP MUSCLES OF SCALP BLOOD SUPPLY OF SCALP LYMPHATIC DRAINAGE OF SCALP NERVE SUPPLY OF SCALP APPLIED CLINICAL ANATOMY 2  INTRODUCTION The scalp is the soft tissue covering of the calvaria It extends from the superior nuchal lines on the occipital bone to the supraorbital margins of the frontal bone Laterally the scalp extends over the temporal fascia to the zygomatic arches. 3  INTRODUCTION The scalp is a multilayered structure, consisting of five layers of tissues. The first three layers are connected intimately and thus moves as a unit. SCALP serves as a mnemonic for the five layers, thus: S-skin; C-connective tissue (dense); A-aponeurotic layer; L-loose connective tissue; P-pericranium Coronal section of the scalp 4  LAYERS OF THE SCALP SKIN It is thin, except in the occipital region. It contains many sweat and sebaceous glands as well as hair follicles. It has an abundant arterial supply and good venous and lymphatic drainage It is the commonest site for sebaceous cysts. 5  CONNECTIVE TISSUE This layer anchors the skin to the underlying aponeurosis. It forms a thick dense subcutaneous layer of fat and fibrous tissue that lies beneath CONNECTIVE TISSUE the skin. It contains the arteries, veins and nerves supplying the scalp 6  APONEUROSIS The aponeurosis called the epicranial aponeurosis or galae aponeurotica. It is a broad, tough tendinous sheet that covers the calvaria. It serves for muscle attachment for the occipitofrontalis. 7  LOOSE AREOLAR CONNECTIVE TISSUE This layer provides an easy plane of separation between the upper three layers and the pericranium. It provides a plane of access in craniofacial surgery and neurosurgery. It is a sponge like layer with many potential spaces These spaces may distend with fluid resulting from injury or infection, and as such referred to as “danger zone”. 8  PERICRANIUM It is a dense layer of connective tissue that forms the periosteum of the calvaria. It is firmly attached but can be stripped fairly easily from the calvaria of living persons. It is continuous with the fibrous tissue in the cranial sutures. PERICRANIUM 9  MUSCLES OF THE SCALP The muscle of the scalp include; FRONTALIS Occipitalis OCCIPITALIS Frontalis Source: slideshare.net 10  OCCIPITALIS ORIGIN: It arises from the lateral two-thirds of the superior nuchal line of the occipital bone, and from the mastoid part of the temporal bone INSERTION It is attached to the external occipital protuberance and galea aponeurosis. ACTION It pulls the scalp backwards. Source: visiblebody.com 11  OCCIPITALIS BLOOD SUPPLY It is supplied by the occipital artery and drained by occipital vein. NERVE SUPPLY It is supplied by posterior auricular branch of facial nerve. OCCIPITALIS 12  FRONTALIS It is thin and quadrilateral It is broader than occipitalis Its fibres are longer and paler in colour. FRONTALIS 13  FRONTALIS ORIGIN Arises from the front of the aponeurosis INSERTION It blends with the fibres of the procerus, corrugator, orbicularis oculi and overlying skin of the eye brow. Source: Sciencedirect.com 14  FRONTALIS ACTION It elevates the eyebrows and produce wrinkles in the skin of the forehead. BLOOD SUPPLY It is supplied by frontal branch of the superficial temporal artery laterally and the supratrochlear and supraorbital arteries medially NERVE SUPPLY It is innervated is by temporal branch Source: visiblebody.com of facial nerve 15  BLOOD SUPPLY OF THE SCALP The scalp receives rich arterial supply chiefly from the external and internal carotid arteries via Supratrochlear arteries Supraorbital arteries, Superficial temporal arteries Posterior auricular arteries Occipital arteries 16  VENOUS DRAINAGE OF THE SCALP The superficial venous drainage of the scalp follows accompanying arteries of the scalp Supratrochlear vein Supraorbital vein Superficial temporal vein Posterior auricular vein Occipital vein 17  LYMPHATIC DRAINAGE OF SCALP Lymphatics from the anterior part of the scalp and forehead drain into the submandibular lymph nodes. Those from lateral part of the scalp above the ear drains into the superficial parotid (preauricular) nodes. 18  LYMPHATIC DRAINAGE OF SCALP Lymphatics from the part of the scalp above and behind the ear drains into the mastoid nodes. Those from the back of the scalp drain into the occipital nodes. 19  NERVE SUPPLY TO THE SCALP The scalp receives cutaneous innervation from nerves that arise in the trigeminal nerve and cervical nerves. Trigeminal nerve Supratrochlear nerve – It is a branch of ophthalmic nerve which supplies the anteromedial forehead. Zygomaticotemporal nerve It is a branch of the maxillary nerve 20 that supplies the temple.  NERVE SUPPLY TO THE SCALP Supraorbital nerve – A branch of ophthalmic nerve which supplies large portion of the scalp between the anterolateral forehead and the vertex. Auriculotemporal nerve – A branch of mandibular nerve that supplies the skin anterosuperior to the auricle 21  NERVE SUPPLY TO THE SCALP Cervical nerves Lesser occipital nerve – derived from the anterior division of C2, supplies the skin posterior to the ear. Greater occipital nerve – derived from the posterior ramus of C2, supplies the skin of the occipital region. Great auricular nerve – derived from the anterior rami of C2 and C3, and supplies the skin posterior to the ear and over the angle of the mandible. Third occipital nerve – derived from the posterior ramus of C3, and supplies the skin of the inferior region. 22  APPLIED ANATOMY OF THE SCALP CURTIS VERTICIS GYRATA Cutis verticis gyrata is a medical condition usually associated with thickening of the scalp People show visible folds, ridges or creases on the surface of the top of the scalp. The number of folds can vary from two to roughly ten and are typically soft and spongy. The condition typically affects the central and rear regions of the scalp, but sometimes can involve the entire scalp. 23  SCALP INFECTIONS The loose connective tissue layer of the scalp is the danger area of the scalp because pus or blood spreads easily in it. Infection in this layer can also pass into the cranial cavity through emissary veins. Source: emedicinehealth.com 24 GROSS ANATOMY OF FACE OUTLINE INTRODUCTION MUSCLES OF FACE NERVE SUPPLY OF FACE BLOOD SUPPLY OF FACE LYMPHATIC DRAINAGE OF FACE APPLIED CLINICAL ANATOMY 25  INTRODUCTION The face is the anterior part of the human head. It features three of the sense organs namely, the eyes, nose and the mouth. It is important for identity, recognition and communication. There is no deep fascia on the face. Source: Moore et al. (2014). 26  MUSCLES OF THE FACE There are two classes of muscles in the face: - Muscles of facial expression - Muscle of mastication 27  MUSCLES OF FACIAL EXPRESSION There are 6 groups of muscle; Muscle of the eyelid Muscle of the auricle Muscle of the nose Muscles around the mouth Muscle of the neck Muscle of the scalp 28  MUSCLES OF THE EYELIDS The sphincter muscles of the eyelids include; Orbicularis oculi Corrugator supercilii 29  ORBICULARIS OCULI Origin: medial palpebral ligament, lacrimal bone Insertion: lateral palpebral raphe It has 3 parts Orbital Palpebral Lacrimal Action; Blinking and voluntary winking (palpebral) Forceful closure of the eyelids(orbital) 30  CORRUGATOR SUPERCILII Origin: medial end of the superciliary arch Insertion: the skin of the medial half of the eyebrow. Action: Draws the eyebrows towards the midline, causes vertical wrinkles above the nose(frown) 31  MUSCLES OF THE NOSE There are three muscles associated with the nasal group; Nasalis, Procerus, Depressor septi nasi 32  MUSCLES OF THE NOSE Nasalis: Is the largest and best developed. It consists of a transverse part(compressor naris) and alar part(dilator naris) Origin: from the maxilla Insertion: aponeurosis across the dorsum of the nose and alar cartilage. Procerus Origin: nasal bone and upper part of lateral nasal cartilage Insertion: skin of fore head Action: reduce the glare of light and frowning 33  MUSCLES OF THE NOSE Depressor septi nasi Origin: arise from the maxilla above the central incisor tooth Insertion: lower part of the nasal septum. Action: It assist the alar part of the nasalis to widen the nostril during inspiration. 34  MUSCLES OF AURICLE Muscles of auricle It includes; Auricularis anterior, Auricularis superior, Auricularis posterior 35  MUSCLES OF THE LIPS AND MOUTH The sphincter muscle of the lip is the orbicularis oris. Buccinator Lower group of oral muscles Upper group of oral muscles 36  ORBICULARIS ORIS Origin: from median plane of maxilla superiorily and mandible inferiorily Insertion: mucous membrane of the lips Action: closes mouth, compresses and protrudes lips Innervation: buccal branch of facial nerve 37  BUCCINATOR Origin: From the outer surface of the alveolar margins of the maxilla and mandible and pterygomandibular ligament. Insertion: Blends with the muscles of upper lip Action: presses the cheek against teeth expels air from the mouth when playing a wind instrument Innervation: Buccal branch of facial nerve (CN VII) Blood supply: Buccal artery (maxillary artery), facial artery 38  LOWER GROUP OF ORAL MUSCLES The muscles in the lower group consist of depressor anguli oris, depressor labii inferioris mentalis. 39  DEPRESSOR ANGULI ORIS Origin: arises along the side of the mandible below the canine, premolar, and first molar teeth Insertion: skin and the upper part of the orbicularis oris. Action: it depresses the corner of the mouth, active during frowning Innervation: buccal and mandibular branches of facial nerve Blood supply: inferior labial branch of facial artery, mental branch of maxillary artery 40  DEPRESSOR LABII INFERIORIS Origin: arises from the front of the mandible. Insertion: into the lower lip Action: it depresses the lower lip and moves it laterally. Innervation: mandibular branch of facial nerve Blood supply: inferior labial branch of facial artery, mental branch of maxillary artery 41  MENTALIS Origin: arises from the mandible just inferior to the incisor teeth Insertion: into the skin of the chin Action: it raises and protrudes the lower lip Innervation: mandibular branch of facial nerve Blood supply: inferior labial branch of facial artery, mental branch of maxillary artery 42  UPPER GROUP OF ORAL MUSCLES The muscles of the upper group of oral muscles consist of Risorius Zygomaticus major, Zygomaticus minor, Levator labii superioris, Levator labii superioris alaeque nasi Levator anguli oris. 43  RISORIUS Origin ; fascia on the masseter muscle Insertion ; skin of the angle of mouth Action: retracts the angle of mouth. It helps produce a grin. Innervation: buccal branch of facial nerve. Blood supply: superior labial artery 44  ZYGOMATICUS MAJOR Origin: arises deep to the orbicularis oculi Insertion: skin at the corner of the mouth Action: draw the mouth superolaterally as seen in smiling Innervation: buccal and zygomatic branches of facial nerve Blood supply: superior labial artery 45  ZYGOMATICUS MINOR Origin: arises from the zygomatic bone Insertion: the upper lip medial to the corner of the lip Action: They raise the mouth and move it laterally when showing contempt. Innervation: zygomatic and buccal branches of facial nerve. Blood supply: superior labial branch of facial artery. 46  LEVATOR LABII SUPERIORIS Origin: it arises from the maxilla just superior to the infra-orbital foramen Insertion: the skin of the upper lip. Action: it elevates upper lip from nasolabial groove Innervation: zygomatic and buccal branches of facial nerve Blood supply: facial artery, infraorbital branch of maxillary artery 47  LEVATOR LABII SUPERIORIS ALAEQUE NASI Origin: arises from the frontal process of maxilla Insertion: into both the alar cartilage of the nose and skin of the upper lip Action: lift the upper lip and dilates nostril Innervation: zygomatic and buccal branches of facial nerve Blood supply: facial artery, infraorbital branch of maxillary artery 48  LEVATOR ANGULI ORIS Origin: arises from the maxilla, just inferior to the infra-orbital foramen Insertion: into the skin at the corner of the mouth. Action: it elevates the corner of the mouth. It deepens the furrow between the nose and the corner of the mouth during sadness Innervation: zygomatic and buccal branches of facial nerve Blood supply: facial artery, infraorbital branch of maxillary artery 49  PLASTYSMA Origin: Skin/fascia of infra- and supraclavicular regions Insertion: Lower border of mandible, skin of buccal/cheek region, lower lip, modiolus, orbicularis oris muscle Innervation: Cervical branch of facial nerve (CN VII) Blood supply: submental artery (facial artery), suprascapular artery (thyrocervical trunk) Actions: Depresses mandible and angle of mouth, Source: istockphoto.com tenses skin of lower face and anterior neck 50  MUSCLES OF MASTICATION temporalis, masseter, lateral pterygoid medial pterygoid 51  TEMPORALIS Origin: temporal lines on the parietal bone of the skull, superior temporal surface of sphenoid bone Insertion: apex a d medial surface of coronoid process of mandible. Action: anterior fibres elevates mandible;posterior part retracts mandible. Innervation: deep temporal branches of mandibular nerve Blood supply: deep temporal branches of maxillar artery 52  MASSETER Origin: the maxillary process of the zygomatic bone, anterior two thirds of the inferior border of the zygomatic arch. Insertion: lateral surface of ramus and angle of mandible. Action: elevates and protrudes mandible. Innervation: masseteric nerve of mandibular nerve. Blood supply: masseteric artery 53  LATERAL PTERYGOID Origin: Superior head: Infratemporal crest of greater wing of sphenoid bone. Inferior head: Lateral surface of lateral pterygoid plate of sphenoid bone Insertion: Superior head: joint capsule of temporomandibular joint. Inferior head: pterygoid fovea on neck of condyloid process of mandible Action: bilateral contractions;protrudes and depresses mandible. Unilateral contractions; medial movement of mandible Innervation: lateral pterygoid nerve Blood supply: pterygoid branches of maxillary artery 54  MEDIAL PTERYGOID Origin: arises from the medial surface of the lateral pterygoid plate of the sphenoid bone Insertion: medial surface of ramus and angle of the mandible. Action:bilateral contractions; elevates and protrudes mandible Unilateral contractions; medial movement of mandible Innervation: medial pterygoid nerve Source: ncbi.nlm.gov Blood supply: Pterygoid branches of maxillary artery 55  ARTERIAL SUPPLY OF THE FACE The face receives a rich blood supply from two main vessels: Facial artery Superficial temporal arteries. 56  ARTERIAL SUPPLY OF THE FACE The facial artery arises from the external carotid artery Branches The submental artery. The inferior labial artery The superior labial artery The lateral nasal artery The tonsillar branch The glandular branches The angular artery 57  VENOUS DRAINAGE OF THE FACE The face is drained by the facial vein The facial vein is formed at the medial angle of the eye by the union of the supraorbital and supratrochlear veins. It is connected to the superior ophthalmic vein directly through the supraorbital vein Source: Moore et al. (2014). 58  SENSORY INNERVATION OF THE FACE The skin of the face is supplied by branches of the three divisions of the trigeminal nerve. Except for the small area over the angle of the mandible and the parotid gland , which is supplied by the great auricular nerve (C2 and C3). Branches of trigeminal nerve include; Mandibular nerve Maxilla nerve Ophthalmic nerve 59  INNERVATION OF THE FACE Sensory innervation of the face 60  MOTOR INNERVATION OF THE FACE Facial nerve provides motor supply to muscles of facial expression. It divides into its five terminal branches The temporal branch The zygomatic branch. The buccal branch. The mandibular branch The cervical branch; Motor innervation of the face 61  LYMPHATIC DRAINAGE OF FACE Lymph vessels from the frontal region above the root of the nose drain to the submandibular nodes. Vessels from the rest of the forehead, temporal region, upper half of the lateral auricular aspect and anterior wall of the external acoustic meatus drain to the superficial parotid nodes. The auricular lobule, floor of the external acoustic meatus, lower parotid region all drain to the superficial cervical or upper deep cervical nodes. 62  APPLIED CLINICAL ANATOMY BELL’S PALSY Sudden weakness in the muscles on one half of the face. Bell’s palsy may be a reaction to a viral infection. It rarely occurs more than once. Bell‘s palsy is characterised by muscle weakness that causes one half of the face to droop Bell‘s palsy usually resolves on its own within six months. Physiotherapy can help prevent muscles from permanently contracting. 63 NDALU RI NE 64