Anatomy of the Face, Scalp and Parotid Flashcards
List the 5 layers of the scalp, from superficial to deep
Skin Connective tissue Aponeurosis Loose connective tissue Periosteum/pericranium
What is the significance of the loose connective tissue layer of the scalp?
Allows movement of the skin, connective tissue and aponeurosis on the periosteum
Which layer of the scalp contains the neurovascular plane?
Connective tissue (also contains fat)
What are the anatomical margins of the scalp?
Supraorbital margins anteriorly
External occipital protuberance posteriorly
Level of the zygomatic arches laterally
Why do scalp wounds gape?
Because the laceration divides the aponeurosis between the frontalis and occipitalis bellies of occipitofrontalis
Why do scalp wounds often bleed profusely?
Because the neurovascular plane contains rich anastamoses between the internal and external carotid arteries, and these vessels are held open by fibrous septa which adhere to their margins, preventing constriction and clotting
Why is facial infection a risk factor for encephalitis?
Because some blood from the face (particularly a triangular area surrounding the nose) is sometimes drained via emissary veins into the cranial sinuses
Where do the muscles of facial expression originate and insert?
Arise from underlying bone or fascia
Insert into skin of face
Which nerve is the 2nd pharyngeal arch associated with?
Facial (CNVII)
List the 4 layers of the face, from superficial to deep
Skin
Connective tissue
Muscles of facial expression
Periosteum/pericranium
What nerve supplies the skin of the head anterior to the ears?
Trigeminal (CNV)
What are three divisions of the trigeminal nerve and what does each branch supply?
Opthalmic: orbit, forehead, top of scalp
Maxillary: cheek, maxilla
Mandibular: mandible (jaw)
What nerve supplies the skin of the head posterior to the ears?
Dorsal rami of the cervical spinal nerves (except C1 which has no cutaneous supply)
C2: back of head
C3: neck
Below: back
What symptom is characteristic of trigeminal neuralgia?
Episodes of intense, disabling facial pain (tend to be over 1 of the 3 divisions of the nerve)
Which foraminae is each of the branches of the trigeminal nerve associated with?
Opthalmic: superior orbital fissue
Maxillary: foramen rotundum
Mandibular: foramen ovale
Where does the ganglion of the trigeminal nerve sit?
At the apex of the petrous part of the temporal bone
What arteries supply the centre of the forehead and what are these arteries branches of?
Supratrochlear (more medial) and supraorbital (more lateral) branches of the internal carotid artery (via the opthalmic artery)
What is the branch of the external carotid artery supplying the scalp and where does it run?
Superficial temporal, running over the zygomatic arches to the forehead
Describe the course of the facial artery
Given off by the external carotid artery, winds over inferior angle of mandible (following a tortuous course), gives off branches to the face and nose, ends at the medial angle of the eye
What arteries supply the posterior head?
Posterior auricular
Occipital
Describe the lymph drainage of the head
Lymph drains into a ring of lymph nodes surrounding the base of the skull, which includes:
Submental nodes
Submandibular nodes
Pre-auricular and parotid nodes
Mastoid (or post-auricular) nodes
Occipital nodes
These then drain to the deep cervical nodes
What is the parotid and where is it located?
A serous salivary gland located inferior to the zygomatic arch, anterior to the ear and the mastoid process of the temporal bone, superior to the angle of the mandible, posterior to the masseter, and superficial to the styloid process of the temporal bone
What is the significance of the parotid fascia?
Swelling of the parotid gland causes pain because the fascia is a dense fibrous envelop and has no “give”
What four structures are related to the parotid gland?
Parotid lymph nodes are scattered throughout
From superficial to deep, the following structures pass through:
Facial nerve (CNVII)
Retromandibular vein
External carotid artery
Describe the course of the facial nerve
Runs through the internal auditory meatus, travels through the stylomastoid foramen, gives off the posterior auricular branch, enters the back of the parotid gland, creates plexiform arrangement (“pes anserinus”) within the gland from which 5 terminal branches emerge
What two veins join to form the retromandibular vein?
The superficial temporal and maxillary veins
What happens to the external carotid artery as it enters the parotid gland?
Divides into two terminal branches, the superficial temporal and maxillary arteries
Which artery gives off the middle meningeal artery, and how does it enter the skull?
The maxillary artery
Via foramen spinosum
What symptoms does injury to the facial nerve produce?
Full or partial paralysis of the muscles of facial expression on the side of the injury
Flattening of the nasolabial fold
Sometimes dribbling
