Lecture 7 - Scalp, face and parotid Flashcards
Why important?
- Face trauma - need to know structures so you can suture this back up
- Scalp injury
- bells palsy
Layers of the scalp
S- Skin
C - connective tissue (dense) (contains neurovascular structures)
A - aponeurotic layer ( 2 layers tightly connected)
L - loose connective tissue - where infection is , as can move scalp over calvaria
P - pericranium
Blood supply to skull - Exam - need to know what branches supply inferior part of skull
-from external and internal carotid
-Internal carotid - no branch out of neck, however gets out to skull via orbital cavity and forms the supratrochlea A + V, and also supraorbital A + V –> cover frontal and anterior part of skull
-rest of skull - supplied by external carotid artery
=superficial artery and vien, posterior auricular artery and vien - supplying posterior part of skull , superiorl temproal artery and vien
Anterior - supratrochlea, supraorbital A + V
Posterior - Aurciular V + A, SUperifical termporal A + V , occipital A + V
Lymph nodes
- back of head - goes to lymph nodes
- ears - go to mastoid lymph nodes
- preauricular and parotid nodes - from lateral parts of skull
- anterior part drains back to this
Obiccularis oculi
- if lose innovation to this - cannot shut eyes hard
- closing eyes gently - palpebral part
- closing eyes hard is orbital part
Have a bunch of muscles coming to upper lip, and group of muscles going to lower lid
also have buccinator
- damage upper lip - cannot move lip upward
- damage lower lip - cannot move lip downward
- Have buccinator muscle
Muscles of ear
anterior, posterior, superior auricular muscles
Examine trigemminal cranial nerve
can test V1, V2, V3 - can test senstation on face to see if this cranial nerve is working
V1(ophthalmic) - anterior of skull and forehead
V2 (maxillary)
V3 - mandible
Nerves of the anterior face
-nerve to scalp
need to know
Parotid gland - superficial and deep part
Superficial part - sits on ramus of mandible and deep part wrap around the inferior margin of ramus and goes behind the mandible
Innervation to parotid
- investing layer of fascia will cover the parotid gland and mandibular gland - if operating investing layer is around this (parotid fascia) - sensation is C2
- sensation of gland - comes form V3
- If Reticular pain over lower part of jaw (as this is innovated by V3) - then could be parotid gland
- if see lump on face, probably nothign to do with the gland, could be to do with the fasica if it is C2 pain - if pain over neck and posterior part
Pathology to glands and fascia is different
Parotid duct
Mainly serous secretion
- exit final duct which exit the parotid duct from the anterior side
- runs on masseter muscle, when it reaches the anterior border of this muscle it bends 90 degrees, goes deep to the mouth and perforates the buccinator and opens up between first and second superior molar junction
Surface marking of parotid over the face
If someone has a laceration over the face , and you can feel the duct
- runs 3 mm under the skin
- make a line between tragus of ear and mouth
- divide into 3 halfs, Rmiddle third - 1cm box above and below - likley that paratid duct will be in here
Facial nerve - path and branches
-Runs within the parotid gland
-very hard to remove parotid duct cancer due to facial nerve
-exits stylomastoid foreamen, hits parotid gland between deep and superficial part , then runs within superficial part , and divides into two bundles temperozygomatic and cervicofacial
-temperozygomatic - goes to temporal (obularis oculi) , zygomatic and buccal
Cervicofacial - marginal mandibular (bucal muscles), cervical
Why temproal improtant - no fat pad, runs deep to skin, easily damaged
Marignal madnibular - over mandible or below madnible - skin cancer on lower part of mandible - do not touch - send to suregon - patient canot move mouth - saliva comes out
READ THIS PAPER
Paper on facial nerve
afdass
