Head anatomy Flashcards
Describe the layers in the diagram below
A: Skin
B: Aponeurosis
C: Periosteum
D: Dura
E: Connective tissue
F: Loose areolar tissue
G: skull
Name the layer in which the blood supply lies
Connective tissue layer
Describe the arterial supply of the scalp
Arterial supply to scalp from anterior midline to posterior midline is:
-Supratrochlear artery (branch of ophthalmic)
–Supraorbital artery (branch of ophthalmic)
-Superficial temporal (external carotid)
-Posterior auricular (external carotid)
-occipital (external carotid)
Describe the venous drainage of the scalp
Veins matching names of arteries
Externally collected by:
–> facial
–> retromandibular
–> posterior auricular veins
Intracranially:
–> connect with diploic veins of skull
–> connect with dural venous sinuses via valveless emissary veins
What medical conditions can arise form the superfiical temporal artery?
Migraines
Temporal arteriitis
Describe the presentation/investigation/management of temporal arteritis
Presentation:
Commonly
–> throbbing headache
–> tenderness when touching scalp
Rarely
–> symptoms of flu
–> jaw claudication
–> pain in neck/upper arms/shoulder
–> problems with eyesight (double vision/blindness/blurry vision)
Investigation
-FBC, U + E, CRP, ESR
-Temporal artery biopsy
Treatment
-Analgesia
-Steroids
Describe presentation/investigation/management of migraine
Presentation:
-Headache (unilateral), throbbing in nature
-May be associated with nausea/vomiting/aura
-Can be associated with visual disturbance
Ix
-Clinical diagnosis
-If not settling, exclude temporal arteritis
Mx
-Analgesia
-Preventative medications
-Lifestyle advice: managing precipitating factors
What are the surgical considerations when managing patients with scalp lacerations?
-Rich blood supply: profuse bleeding
-Lacerations deep to aponeurosis can gape resulting in difficult skin closure
-Inelastic tissue can make primary closure difficult: may require undermining of adjacent tissues
-
What methods could you use to close simple scalp lacerations?
-Likely to require sutures or staples
-Remain in situ for 5-7 days
What type of sutures should be used for closure?
-Superficial layer: Non asorbable 3’0 or 4’0
-Deep layer Absorbable 3’0 or 4’0
What is the clinical significance of infections involving the scalp?
-Emissary veins have no valves so superfiical scalp infections and also superficial infections of the face can spread intracranially to dural venous sinuses including cavernous sinus
What is the commonest lump to present in the scalp and why?
-Large number of sebaceous glands in scalp
-Sebaceous cyst
-Ulcerative or nodulo-ulcerative lesions can be cutaneous malignancies e.g. BCC or SCC
Describe the sensory nerve supply to the face
-Trigeminal nerve
–> V1 (sensory)
–> V2 (sensory)
–> V3 (mixed sensory and motor)
Note: Cutaneous sensation to scalp and face anterior to pinna is supplied by trigeminal nerve. Posterior to pinna is supplied by nerve roots C2 and C3 (greater and lesser occipital nerves) and by greater auricular nerve
Name the branches of the ophthalmic division of the trigeminal nerve
NFL
Lacrimal
Nasociliary
Frontal
Name the branches of maxillary division of trigeminal nerve
Infraorbital
Zygomatic
Superior alveolar
Palatine
Pharyngeal
Superior labial
Name the main divisions of the mandibular division of trigeminal nerve
After exiting foramen ovale gives off branches to:
–> medial pterygoid
–> tensor tympani
–> tensor veli palatini
Then divides into (predominantly motor) anterior branch and (predominantly sensory) posterior branch
Anterior division
–> Lateral pterygoid
–> masseteric
–> deep temporal
–> buccal
Posterior division
–> auriculotempral
–> lingual
–> inferior alveolar (also nerve to mylohyoid which supplies mylohyoid and anterior belly of digastric)
Name the sensory branches of the mandibular division of the trigeminal nerve
-Buccal
-Auriculotemporal
-Inferior alveolar
-Lingual
Name the branches of the facial nerve within the substance of the parotid gland
Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical
What do the branches of facial nerve supply?
Temporal
–> frontalis (raises eyebrows)
–> orbicularis oculi (closes eyes)
Zygomatic
–> Orbicularis oculi
Buccal
–> Risorius (smiling)
–> buccinator (mastication)
–> orbicularis oris (pucker and close lips)
Marginal mandibular
–> depressor labii inferioris
–> depressor anguli oris
–> mentalis (allows pouting)
Cervical
–> platysma
What does the marginal mandibular branch of the facial nerve supply? What is the clinical significance of its course?
–Depressor anguili oris (frowning, depresses corner of mouth)
-Depressor labii inferioris (depresses lower lip)
-Mentalis (allows pouting)
Nerve runs inferior to the mandible putting it at risk in surgeries such as submandibular gland excision or carotid endarterectomy
Name the structures that attach to the styloid process
-Stylohyoid muscle and ligament
-Styloglossus
-Stylopharyngeus
-Stylomandibular ligament