Muscles Of Mastication, Facial Expression and Scalp Flashcards
What innervates the muscles of facial expression and mastication?
Facial nerve
Trigeminal nerve- mandibular branch
What is the main sensory nerve of the face and scalp?
Trigeminal nerve
What are the five branches of the facial nerve that supply muscles of facial expression?
Temporal Zygomatic Buccal Marginal mandibular Cervical
“To Zanzibar By Motor Car”
What are the four muscles of mastication? What does each do?
Masseter- elevates mandible, close mouth
Temporalis- elevates and retracts mandible, close mouth
Med pterygoid- elevates mandible, closes mouth
Lat pterygoid- unilat side to side, bilat protracts mandible
What are the two parts of obicularis occuli called? What do each do?
Palpebral- gently closes
Orbital- tightly closes
What are the 6 muscles of facial expression?
Obicularis occuli obicularis oris Buccinator Levator palpebrae superioris Ocipitofrontalis Corugator supercili
What do obicularis oris and buccinator do?
Purses lips
Pulls cheeks to teeth, prevents food accumulating
What does corugator supercili do?
Draws eyebrows together and wrinkles nose
What does levator palpebrae superioris do? What innervates it?
Elevates upper eyelid
Occulomotor nerve
What does occipitofrontalis do?
Raises eyebrows and wrinkles forehead
What are the 5 layers of the scalp?
Skin- hair follicles and sebaceous glands
CT- dense, highly vascularised-bleeds profusely-vessels attach
Aponeurosis- epicranial, connects occipitofrontalis
Loose CT- separates aponeurosis and periosteum
Periosteum- outer layer of skull bone
What is the danger area in the scalp?
Loose CT layer
Pus and blood can easily spread to cranial cavity along emissary veins causing meningitis
What is the blood supply to the scalp?
ECA- sup temporal, post auricular, occipital
Ophthalmic artery
What is the venous drainage of the scalp?
Sup temporal
Occipital
Post auricular
Supraorbital and supratrochlear
3 reasons why scalp lacerations bleed profusely
Pull from occipitofrontalis prevents closure
Vessels adhered to CT preventing vasoconstriction
Many anatomoses
Why is there no bone necrosis of skull if scalp laceration?
Skull mostly supplied by middle meningeal artery
Innervation of scalp?
Trigeminal- supratrochelar, supraorbital, zygomaticotemporal, auriculotemporal
Cervical- lesser and greater occipital
