W20-L1: Face, Scalp and Parotid Flashcards
What are the margins of the scalp?
Extends anteriorly to the supra-orbital margins, posteriorly to the external occipital protuberance, and laterally to the zygomatic arches
What are the layers of the scalp?
Skin Connective tissue Aponeurotic layer Loose connective tissue Peri-cranium
Which layer of the scalp allows for movement of scalp over the skull?
The loose connective tissue layer
Describe the occipitalitis frontalis muscle
Has two bellies and an aponeurosis between
Why do scalp wounds bleed more?
- Scalp wounds gape as each muscle belly of frontalis occipitalis contracts
- There are rich anastomoses between internal and external carotid
- Arteries are attached to fibrous septae and this prevents clotting
In which layer of the scalp is the neurovascular structures?
Connective tissue
What are the layers of the face?
4 similar layers to scalp, but no loose connective tissue and aponeurosis is replaced by facial muscles
Origin and insertions of facial muscles
Origins is the bones over which they lie, and insert into the skin of the face
To what structure are facial muscles related to and what do they act as?
Related to an orifice, and can act as sphincters or dilators
From which pharyngeal arch are they derived?
2nd
Which cranial nerve supplies the muscles of the face?
CN VII
Dermatomes of head and neck
Anterior of scalp (to ears) gets V1, posterior is dorsal rami of C2 , then maxillary area is V2, mandibular is V3 and posterior neck is C3
What are the two internal carotid derived branches suppling the face?
Supra-orbital and supra-trochlear (more medial)
What supplies the face from the external carotid artery?
Facial artery, which winds around the inferior angle of the mandible then a tortuous course to the medial angle of the eye, gives off branches as it goes
What supplies the lateral aspect of the scalp?
Superficial temporal artery
Suppling the posterior scalp are which arteries?
Occipital artery and posterior auricular artery, both branches of the external carotid
What is the difference between the facial artery and vein
Vein is straighter and more superficial
Why is Thrombophlebitis of the facial vein possible and why is it important?
Emissary veins of the face can drain into the cavernous sinus, can cause meningitis and encephalitis
Where are lymph nodes in the head?
Ring of lymph nodes that surround the base of the skull, submental, sub-mandibular, pre-auricular, parotid, mastoid and occipital nodes
Where do lymph nodes in the head drain to?
Deep cervical nodes
What is the parotid gland?
serous salivary gland wrapped in fascia
Anatomical landmarks of the parotid gland
It is below the zygomatic arch, in front of the mastoid process, above angle of mandible
If you removed the parotid gland would you see?
styloid process
Where does the parotid Duct run?
parotid duct from anterior border of parotid onto massater, turns inwards pierces buccinater
within parotid
gland from superficial to deep it is…
CN VII
Retromandibular vein External carotid artery
Scattered throughout the parotid glands are
Lymph nodes
Where does the Facial nerve exit the skull?
Exits the posterior cranial fossa by internal acoustic meatus and exit by the styloid mastoid foramen
Course of the Facial nerve outside the skull
Gives off posterior auricular nerve which goes to occipitalis, enters posteromedial surface of parotid gland and then forms a plexiform arrangement within
What are the 5 terminal branches of the plexiform arrangment of CN VII
Temporal Zygomatic Buccal Mandibular Cervical "To zanzibar by motor car"
What does the facial nerve supply?
Muscles of facial expression
Where is the retromandibular vein and what is it formed by?
In the parotid gland and formed by the superficial temporal veins and maxillary veins
What are the two terminal branches of the external carotid artery?
Enters the parotid gland and then gives off maxillary artery and superficial temporal artery
What is Facial nerve paralysis called?
Bell’s Palsy
