Diessction 1-Skull, Face And Scalp Flashcards
Ophthalmic Division of the Trigeminal Nerve (V1)
Skin of the forehead, upper eyelids and nose
Maxillary division of the Trigeminal Nerve (V2)
Skin of the lower eyelid, cheek and upper lip
Mandibular Division of the Trigeminal Nerve (V3)
Skin of the lower face and part of the side of the head
Cervical Spinal Nerves 2 and 3
Skin of the back of the head and the area around the ear
Facial Nerve (CN VII)
Motor innervation to the muscles of facial expression
Platysma Muscle
Extends into the face along the inferior border of the mandible
Inferior attachment is the superficial fascia of the upper thorax
Forms a sheet of muscle that covers the anterior neck
Superior attachment: inferior border of the mandible, skin of the cheek and angle of the mouth
Masseter Muscle
Thick muscle of mastication
Parotid duct
Diameter of a probe handle and it crosses the lateral surface of the masseter muscle about 2cm inferior to the zygomatic arch
Duct turns deeply at the anterior border of the masseter muscle and pierces the buccinator muscle of the cheek and drains into the oral cavity
Facial Nerve (path)
Emerges from the base of the skull through the stylomastoid foramen, just deep to the inferior aspect of the ear
Branches radiate from that point
At the anterior border of the parotid gland, locate branches of the facial nerve. It exits the stylomastoid foramen and forms a plexus within the substance of the parotid gland.
From this plexus branches of the facial nerve exit the anterior border of the gland
Branches of the Facial Nerve
Temporal branch (crosses the zygomatic arch)
Zygomatic branch: crosses the zygomatic bone
Buccal branches: cross the superficial surface of the masseter muscle to innervate the buccinator muscle
Mandibular branch: parallels the inferior border of the mandible
Cervical branch: crosses the angle of the mandible to enter the neck
Facial Artery
Crosses the inferior border of the mandible at the anterior edge of the masseter muscle
Facial Vein is located posterior to the facial artery
(Vein is straighter and takes a more direct course to the nose while the artery is more coiled and winding)
Branches of the facial artery
Inferior labial and superior labial arteries given off near the angle of the mouth
Angular artery
Continuation of the facial artery at the lateral side of the nose
Angular Vein
Has clinically important anastomotic connection with the ophthalmic veins in the orbit
Orbicularis Oculi Muscle
Encircles the palpebral fissure (opening of the eyelid)
Medial attachment: medial orbital margin, medial palpebral ligament and the lacrimal bone
Lateral attachment: skin around the orbital margin
Innervation: Temporal and zygomatic branches of the facial nerve
Orbital part of the Orbicularis oculi muscle
Surrounds the orbital margin and is responsible for the tight closure of the eyelid
Palpebral Part of the Orbicularis Oculi Muscle
A thinner portion, which is contained in the eyelids and is responsible for blinking of the eyelid
Orbicularis Oris Muscle
Medial attachments to the maxilla, mandible and skin in the median plane and a lateral attachment to the angle of the mouth
It’s a sphincter of the mouth
Buccinator Muscle
Has proximal attachments to the pterygomandibular raphe and the lateral surfaces of the alveolar processes of the maxilla and mandible
distal: angle of the mouth
Compresses the cheek against the molar teeth, keeping food on the occlusal surfaces during chewing
Levator Labii Superioris Muscle
Has a superior attachment to the maxilla just below the orbital margin and an inferior attachment to the upper lip. It elevates the upper lip
Zygomaticus Major Muscle
Has a lateral attachment to the zygomatic bone and a medial attachment to the angle of the mouth. It draws the angle of the mouth superiorly and posteriorly
Depressor Anguli oris muscle
Has an inferior attachment to the mandible and a superior attachment to the angle of the mouth (corner of the mouth) it depresses the angle of the mouth
Risorius
Arises from the parotid fascia and buccal skin and inserts into the angle of the mouth; retracts the angle of the mouth to produce a smile
Levator anguli oris
Arises from infraoribtal maxilla and inserts into the angle of the mouth; elevates the angle of the mouth
Facial Nerve Bell’s palsy
Sudden loss of control of the muscles of facial expression on one side of the face. The patient presents with a drooping of the mouth and inability to close the eyelid on the affected side
Supraorbital Nerve
A branch of the ophthalmic division (V1) of the trigeminal nerve that passes through the supraorbital notch. It is seen when the scalp is studied
Infraorbital Nerve
A branch of the maxillary division of the Trigeminal nerve (V2) that passes through the infraorbital foramen. It supplies sensory innervation to the inferior eyelid, side of the nose and upper lip
Mental Nerve
A branch of the mandibular division of the trigeminal nerve (V3) that passes through the mental foramen
Sensory innervation to the lower lip and chin
Mental Nerve, artery and vein
All exit the mental foramen
Dental Anesthesia
Study the infraorbital foramen and infraorbital canal in the skull. For purposes of dental anesthesia, the infraorbital nerve may be infiltrated where it emerges from the infraorbital foramen. The needle is inserted through the oral mucosa deep to the upper lip and directed superiorly
Layers of the Scalp
Skin
SubQ Connective tissue: contains vessels and nerves of scalp
Aponeurosis (epicranial aponeurosis): connecting the frontalis muscle to the occipitalis muscle
Loose Connective Tissue: Permits the scalp to move over the calvaria
Pericranium: the outer periosteum of the cranial bones
Scalp (in the clinic)
The CT layer of the scalp contains collagen fibers that attach to the external surface of blood vessels. When a blood vessel of the scalp is cut, the CT holds the lumen open, resulting in profuse bleeding. If an infection occurs in the scalp, it can spread within the loose CT layer. Therefore the loose CT layer is often called the “dangerous area”. From the “dangerous area” the infection may pass into the cranial cavity through emissary veins
Occipitalis
Inferior attachment: occipital bone
Superior: epicranial aponeurosis (galea aponeurotica)
innervation: facial nerve
Frontalis
Superior attachment: epicranial aponeurosis
inferior: skin of the forehead and eyebrows
Innervation: facial nerve
Supraorbital nerve, artery and vein
Exit the supraorbital notch and enter the deep surface of the scalp
