Scalp and Superficial Face Flashcards
What are the 5 layers of the scalp from superficial to deep?
Skin Connective tissue Aponeurosis Loose CT Pericranium
In what layer of the scalp would you find passage for nerves, arteries, and veins?
Connective tissue plane
Emissary veins drain the ______ layer of the scalp to the dural venous sinuses
Loose CT
What are the 2 primary arterial sources for the vasculature of the superficial face and scalp?
Internal carotid a.
External carotid a.
The primary arterial supply of the superficial face and scalp stems from either the internal carotid a. or external carotid a. What are the branches of these vessels present on the scalp?
Internal carotid a.:
Supratrochlear a.
Supraorbital a.
External carotid a.:
Superficial temporal a.
Posterior auricular a.
Occipital a.
What are the nerves supplying the scalp?
Supratrochlear n. (CN V1) Supraorbital n. (CN V1) Zygomaticotemporal n. (CN V2) Auriculotemporal n. (CN V3) Lesser occipital n. (C2,C3) Great occipital n. (C2)
The neurocranial aponeurosis connects what 2 muscles of the scalp?
Frontalis m.
Occipitalis m.
Failure to repair large, horizontal lacerations of the _____ of the scalp can cause the frontalis m. to contract asymmetrically, which can cause a significan cosmetic deformity of the forehead.
Closure of galea lacerations is also important for protection of the _______ that is vulnerable to infection
Aponeurosis
Loose CT
Why is the 4th layer of the scalp considered the most dangerous area?
This is the loose areolar tissue - at risk of infection in subaponeurotic space with pus collection which can readily spread to intracranial sinuses through the valveless emissary veins
Why do deep lacerations to the scalp tend to bleed profusely? (3 primary reasons)
- The pull of the occipitofrontalis m. prevents the closure of bleeding vessel and surrounding skin
- The blood vessels to the scalp are adhered to dense CT, preventing vasoconstriction that normally occurs in response to damage
- The blood supply to the scalp is made up of many anastomoses, which contribute to profuse bleeding
T/F: loss of blood supply to the scalp leads to bone necrosis
False; it does not lead to bone necrosis as most of the blood supply to the skull comes from the middle meningeal a.
T/F: the maxillary bone is considered a paired facial bone
True
The major vessels from the external carotid supplying the superficial face and scalp are the facial a., occipital a., posterior auricular a., and superficial temporal a.
Of these, the facial a. has 4 branches — what are they
Inferior labial a.
Superior labial a.
Lateral nasal a.
Angular a. (Terminal branch)
Other vessels supplying the superficial face and scalp include the ____ a., which is a terminal branch of the inferior alveolar a.; as well as the supraorbital a. and supratrochlear a., the lateral and medial ______ aa. which are terminal branches of the ophthlamic a. arising from the _________ a.
Mental; palpebral; internal carotid
Most of the venous drainage of the superficial face and scalp occurs via ______ vv.
External jugular
T/F: as a general rule, cranial nerves innervate the anterior head and face, while spinal nerves innervate posterior head and scalp
True
What 4 nerves supply somatosensory innervation to the face and scalp?
Trigeminal n.
Greater occipital n.
Lesser occipital n.
Greater auricular n.
What n. supplies somatomotor innervation to the face and scalp?
Facial n.
The trigeminal supplies part of the somatosensory innervation to the face. What are the 5 branches of V1 (ophthalmic division) contributing to the face?
Supraorbital n. Supratrochlear n. Lacrimal n. Infratrochlear n. External nasal n. (Anterior ethmoidal n.)
[note that supraorbital n. and supratrochlear n. emerge from supraorbital foramen]
The trigeminal supplies part of the somatosensory innervation to the face. What are the 3 branches of V2 (maxillary division) contributing to the face?
Infraorbital n.
Zygomaticofacial n.
Zygomaticotemporal n.
[note that infraorbital n. emerges from infraorbital groove tot he infraorbital foramen]
The trigeminal supplies part of the somatosensory innervation to the face. What are the 3 branches of V3 (mandibular division) contributing to the face?
Auriculotemporal n.
Buccal n.
Mental n.
[auriculotemporal and buccal arise from infratemporal fossa, mental comes from mental foramen as terminal branch of inferior alveolar n.]
What virus tends to follow the trigeminal dermatomes very precisely?
Herpes zoster (shingles)
What is tic douloureux?
Aka trigeminal neuralgia; sensory disorder of the trigeminal n. characterized by sudden attacks of excruciating facial pain
Trigeminal neuralgia predominantly affects what branch(es) of the trigeminal n.?
V2 and V3 divisions
What probably causes most cases of trigeminal neuralgia?
Compression of trigeminal n. root by a blood vessel
What are the specific areas of pain caused by trigeminal neuralgia in the V2 and V3 branches?
V2 = upper lip, upper teeth, upper gum, cheek, lower eyelid, and side of nose
V3 = lower lip, lower teeth, lower gum and side of tongue, part of lower jaw in front of the ear to the side of the head
Branches of facial n. supplying somatomotor modality to the face
Posterior auricular Temporal Zygomatic Buccal Mandibular Cervical
What is the general difference in function between the masseter m. and the buccinator m.?
Masseter = muscle of mastication (under control of CN V)
Buccinator = muscle of facial expression (motor control by CN VII, sensory control by CN V)
The facial nerve and its branches pass through what gland to get to the muscles of facial expression?
Parotid gland
What muscle of facial expression is primarily responsible for frowning?
Depressor anguli oris m.
What muscle of facial expression is primarily responsible for blinking/closing the eyes
Orbicularis oculi m.
What muscle of facial expression is primarily responsible for smiling?
Zygomaticus major m.
What muscle of facial expression is primarily responsible for making a kissing face?
Orbicularis oris m.
What muscle of facial expression is primarily responsible for wrinkling the forehead by raising the eyebrows?
Frontal belly of occipitofrontalis m.
What muscle of facial expression is primarily responsible for tensing the skin of the neck?
Platysma m.
What muscle compresses the cheek and holds food between teeth during chewing
Buccinator m.
What muscle draws the lower lip inferiorly
Depressor labii inferioris m.
What muscle opens the lips, raises and furrows the upper lip (“elvis” lip snarl)
Levator labii superioris m.
What muscle protrudes the lower lip (“pout”) and wrinkles the chin?
Mentalis m.
What muscle draws the corner of lip laterally and tenses the lips, acting as a synergist of zygomaticus?
Risorius m.
What is the largest salivary gland?
Parotid gland
The parotid gland and duct receive sensory innervation from the ____ n. as well as parasympathetic innervation from the ______ n. via the _______ n. (postsynaptic from the otic ganglion)
Greater auricular; glossopharyngeal; auriculotemporal
What type of fascia surrounds/forms a capsule around the parotid gland?
Investing layer of deep fascia (splits into thick superficial layer and a thinner weaker deep layer of parotid fascia)
7 Facial anatomy layers
- Skin (epidermis and dermis) layer
- Superficial fat (subcutaneous) layer
- SMAS (superficial musculoaponeurotic system)
- Retaining ligaments and spaces
- Deep fat layer (absent on the forehead)
- Deep fascia (splitting around and investing parotid)
- Bones
What layer of facial anatomy is absent in the forehead?
Deep fat layer (layer 5)
The SMAS is a layer of tissue deep to the subcutaneous tissue of the face and neck. Although it is fused with the ____ fascia, it is surgically elevated to perform lower face lifts. The SMAS extends from the ______ to the galea aponeurotica and is continuous with the ______ fascia and galea. It connects to the dermis via vertical septa
Parotid; platysma; temporoparietal
Given that the SVE branches of the _____ n. are invested in the parotid gland, particular care must be taken when resecting masses from the gland. It is essential to identify all branches before/while resecting
Facial
