Scalp, Facial Muscles of Expression and Mastication Flashcards
What is the scalp?
- the part of the head that extends from the superciliary arches anteriorly to the external occipital protuberance and superior nuchal lines posteriorly
- laterally it continues inferiorly to the zygomatic arch
What are the 5 layers of the scalp?
- skin
- dense subcutaneous tissue
- epicranial aponeurosis
- loose areolar connective tissue
- periosteum
What are the boundaries of the scalp?
- anteriorly - eyebrows
- laterally - ears/zygomatic arches
- posteriorly - superior nuchal line
Describe the skin of the scalp?
- thick
- hair bearing
- contains numerous sebaceous glands
Describe the connective tissue of the scalp?
- is fibrofatty
- the fibrous septa uniting the skin to the underlying aponeurosis of the occipitofrontalis muscle
- has numerous arteries and veins
> the arteries are branches of the external and internal carotid arteries and a free anastomosis takes place between them
Describe the epicranial aponeurosis of the scalp?
- thin + tendinous sheet
- unites the occipital and frontal bellies of the occipitofrontalis muscle
- the lateral margins of the aponeurosis are attached to the temporal fascia
Describe the loose areolar tissue of the scalp?
- occupies the subaponeurotic space
- loosely connects the epicranial aponeurosis to the periosteum of the skull (pericranium)
- contains a few small arteries
- contains emissary veins
> valveless veins that connect the superficial veins of the scalp and the diploic veins of the skull bones and with the intracranial venous sinuses
Describe the clinical correlates of the loose areolar tissue of the scalp?
- known as dangerous layer of the scalp
- emissary veins open here and carry any infections inside the brain (venous sinus)
- bleeding lead to black eye
Describe the pericranium of the scalp?
the periosteum covering the outer surface of the skull bones
Describe the muscle of the scalp?
occipitofrontalis muscle
- anteriorly = frontal belly
- posteriorly = occipital belly
- aponeurotic tendon (epicranial aponeurosis) connecting the two
Describe the occipital belly of the occipitofrontalis muscle of the scalp?
origin - highest nuchal line of occipital bone
insertion - epicranial aponeurosis
nerve supply - facial nerve
action - moves scalp on skull and raises eyebrows
Describe the frontal belly of the occipitofrontalis muscle of the scalp?
origin - skin + superficial fascia of eyebrow
insertion - epicranial aponeurosis
nerve supply - facial nerve
action - moves scalp on skull and raises eyebrows
What are the 3 layers of the skull cap?
- outer table
- diploe
- inner table
What is the function of emissary veins?
drain blood from the external surface of the skull into the dural sinuses
Describe the course and function of the diploic veins?
- course in diploe
- connect both cranial cavity and surface of skull
- drain blood from the space within the bone of the skull (diploic space) into the dural sinuses
- can transmit infection from scalp to brain via emissary veins
What is the dangerous area of the scalp?
the 4th layer of the scalp - loose areolar tissue
- infection in the subaponeurotic space with pus collection readily spread to intracranial sinuses through emissary veins (valveless)
What is the clinical relevance of the scalp?
- infection spreading from loose areolar connective tissue, via emissary veins, to meninges-meningitis
- hematoma
How is the nerve and arterial supply of the scalp divided?
- in front of auricle
- behind auricle
What are the 5 nerves in front of auricle for the nerve supply of the scalp?
sensory (from trigeminal nerve)
1. supra-trochlear nerve
2. supra-orbital nerve
3. zygomatico-temporal nerve
4. auriculo-temporal nerve
motor
1. temporal branch of facial
Name the 5 nerves behind auricle of nerve supply of the scalp?
sensory (from cervical nerves)
1. great auricular n.
2. lesser occipital n.
3. greater occipital n.
4. 3rd occipital n.
motor
1. posterior auricular branch of facial nerve
Describe the arterial supply of the scalp?
3 in front of auricle
1. supratrochlear
2. supraorbital
3. superficial temporal
2 behind auricle
1. posterior auricular
2. occipital
What is an avulsion?
tearing away of a structure or part of the scalp
What are the 5 facial muscle groups?
- Muscle of the forehead - frontalis, as part of the occipitofrontalis
- Muscles of the mouth
- Muscle of the eyelids
- Muscle of the nose
- Platysma
- all are supplied by CN VII
Name the muscles of the mouth?
Orbicularis oris
Zygomaticus major
Zygomaticus minor
Levator labii superioris
Levator labii superioris alaque nasi
Buccinator
Depressor anguli oris
Depressor labii inferioris
Mentalis
Risorius
Platysma
Name the muscles of the eyelids?
Orbicularis oculi
- Orbital part
- Palpebral part
Name the muscles around the eyes?
- corrugator supercilii
- procerus
- orbicularis oculi
- nasalis
What are the actions of the muscles around the eyes?
- orbicularis oculi - closes the eyes
- corrugator supercilii - draws the eyebrows together
- procerus - pulls down the skin of the forehead
- nasalis - widens nostrils
Name the muscles of facial expression?
- risorius
- depressor anguli oris
- procerus
- nasalis
- Levator labii superioris alaeque nasii
- orbicularis oris (oral sphincter)
- orbicularis oculi
- depressor labii inferioris
- levator labii superioris
- zygomaticus minor
- zygomaticus major
- platysma
Name the muscles of mastication?
Maseeter
Temporalis
Lateral pterygoid
Medial pterygoid
What is buccal pad fat and where is it located?
what = Brown fat … for heat generation, especially for children
where = Between masseter and buccinator muscles
Where does the arterial supply of the scalp originate from?
- external carotid artery
- opthalmic arrtery > branch of internal carotid artery
Name the arteries of the face that stem from the external carotid artery?
Facial artery
Superficial temporal artery
Transverse facial artery
Name the arteries of the face that stem from the internal carotid artery?
- supraorbital artery
- supratrochlear artery
Name the 2 important veins of the face?
Facial vein
Retromandibular vein
> Facial veins have no valves
> Connection of facial veins, pterygoid plexus and cavernous sinus
Describe the lymph drainage of the face?
Submental lymph nodes
Submandibular lymph nodes
Parotid lymph nodes
Describe the location of the parotid duct?
One finger-breadth below zygomatic arch
Open into the mouth cavity (vestibule) at the level of the 2nd molar tooth (crown)
Describe the location of the facial nerve?
Comes out from stylomastoid foramen
Name the 5 branches of the facial nerve?
Temporal
Zygomatic
Buccal
Mandibular
Cervical
What is facial palsy?
refers to weakness of thefacialmuscles, resulting from temporary or permanent damage to thefacialnerve.
What is Bells palsy?
is a condition in which the muscles on one side of yourfacebecome weak or paralyzed.
> causing it to droop or become stiff on that side. It’s caused by either a trauma to facial nerve (the seventh cranial nerve).
Name the symptoms of Bells palsy?
No wrinkle of forehead
Angle of mouth drops
Sagging lower eyelid
Other signs relating to malfunctions of structures innervated by facial nerve
Name the sensory innervation of the trigerminal nerve?
Ophthalmic division
Maxillary division
Mandibular division
What does the trigeminal nerve supply?
Iviuscles oi mastication
• Messeter
• Temporalis
• Medial pterygoid
• Lateral pterygoid
Name the foremen the branches of the trigeminal nerve leave the middle cranial fossa out of?
V1 - OPHTHALMIC - Sup. Orbital fissure -
GSA
V2 - MAXILLARY - Foramen rotundum
GSA
V3 - MANDIBULAR - Foramen ovale - GSA
& SVE
