Scalp, face and parotid gland Flashcards
Whatare the layers of the scalp?
5 layers Skin Connective tissue (fatty layer) Aponeurotic layer Loose connective tissues Pericranium
What innervates the skin over the skull?
Trigeminal is the main sensory of the anterior skull
Anterior and posteror rami of the cevical nerves C2-C4 are the main contributor to the posterior skull.
Where to put the anaesthesia depends on where the nerves are running from.
What is the blood supply of the skull?
The internal and external carotid arteries contribute
The branches of the external carotid supply 2/3rds of the skull (ot the aterior egion). These branches include the posterior auricular artery.
The internal jugular vein branches in the skull into the supratrochlear artery and the supraorbital artery which exits the eye cavity and supplies the anterior skull
What are the muscles facial expression?
Platysma - Attaches to the lower mandible and attaches to the clavicle and runs in the superficil fascia.
Occipitofromtalis - has two bellies (anterior belly is called fromtalis and posterielly is called occiptalis) on either side of the skull with an aponeurosis that covers the skull (is on one the five skull layers).
Auricularis mucles - three muscles, above, front and behind the ear (superior, anterior and posterior)
obiculari occuli.
What do we need to know about the muscles of the lip?
That there is a group of muscles that goes to the upper lip and anther that goes to the lower lip.
Different innervation.
Some muscles go to the corner of the mouth. They pull up or down on the lip
What innervates obiccularis oculi and what happens if it is damamed? What are the two regions of this muscle?
The facial nerve. Can’t shut the eye.
Palpebral (inner) and orbital (outer)
What are the muscles of the nose?
Called nasalis
What is the muscle in the cheeks?
The buccinator. The parotid duct perforates it.
What nerves proevide sensory innervation to the face?
All branches of the trigeminal:
Opthalamic
Maxillay
Mandibular
Where does the opthalamic division of trigeminal run and what are it’s branches and where does it supply sensory information?
It run through the orbitalcanal and runs p the skull with he supraorbital and supratrochlear nereve branches.
The lacramal nerve goes to the lacramal gland.
Ifratrochlear branch and external nasal nerve
Where does the paroid gland sit?
The sperificial portion of theparotid sits on the ramus of the mandable.
Below the zygomatic arch, in front of the ear.
The deep branch wraps around the ramus
What innervats the parotid gland and it’s fascia?
Sensory: parotid gland is from V3 and the parotid fascia is from C2 (great auricular nerve).
Secretomotor: parasympathetic fibres CNIX and a little from V3
Sympathetic fibres: superior cervical ganglion via external carotid artery
Where does the fascia around the paroid gland come from?
Continuation of the investing layer of the neck.
Innervation for the fascia comes from the great auricular nerve (C2)
What innervats the parotid gland and it’s fascia?
Sensory: parotid gland is from a branch of V3 (auriculotemporal nerve) and the parotid fascia is from C2 (great auricular nerve).
Secretomotor: parasympathetic fibres CNIX and a little from V3
Sympathetic fibres: superior cervical ganglion
Where does the parotid duct run?
It opens in the mouth next to the upper second molar.
Where does the parotid duct run?
Formed in the deep lobe, emerging at the anterior order of the parotid it travels superficially over the masseter muscle then pierces the buccinator. It opens in the mouth next to the upper second molar.
What is the surface marking of the parotid duct
Make a line from the tragus to the corner of the mouth (cheilion). Then take the middle third and go 1.5 cm above and below that line you will find he parotid duct below there.
What are the branches of the facial nerve?
The facial nerve gets out of the stylomastoid foramen then it runs through the parotid gland in two divisions, temporalzygomatic and cervicofacial.
Temporozygomatic branches:
Temporal
zygomatic
Buccal
Cervicofacial divisions:
Marginal mandibular
cervical
The temporal and marginal mandibular divisions get damaged often by clinicians. Their course is superficial. Damage to these areas = send to plastic surgeon
What happens if you damage the temporal or marginal mandibular nerves?
Temporal: Loss of ability to close the eye because it sometimes innervates the obicularis oculi.
Marginal mandibular: muscles going to the lower lip = lip being puled up by the upper muscles of the lip.
Where does the facial nerve run in the parotid gland and what is deep to the facial nerve?
It runs between the mastoid and styloid process penetrates the parotid gland between the deep and supeficial parotid and then crosses the retromandibular vein, the external carotid artery, the mandible and the masseter muscle.
You have to see the nerve before you see the blood vessels.
