Skull and face Flashcards
Differences between the adult and neonatal skull
8
- Smaller facial skeleton by comparison to cranial vault; relatively large orbits
- Little or no development of the paranasal sinuses
- No development of the mastoid process
- No bony external auditory meatus – just tympanic ring
- Open metopic (midfrontal) suture
- Fontanelles at junctions of skull bones (anterior, posterior, lateral)
- No teeth and therefore small jaw, low oblique jaw ramus
- No obvious muscle scars
Adult skull Bones (external)
11
- nasal;
- frontal;
- maxilla;
- parietal;
- occipital;
- temporal;
- zygomatic;
- sphenoid;
- lacrimal;
- ethmoid;
- palatine
Temporal Line
Edge of crest for insertion of the temporalis muscle
Nuchal Lines
Inserts of muscles into the occipital bone
Stutures
3
Sagittal
Coronal
Lambdoid
Infratemporal fossa
3
- cavity below and medial to the zygomatic arch.
- The bulk of this is taken up by lateral and medial pterygoids.
- Does not open into the cranial cavity
Palate includes
Incisive Foramen
Palatine process of Maxilla
Palatine bone
Greater & Lesser Palatine foramen
What are 1 and 2 and what (3) are they divided by?

- Pterion
- Anerion
- Sphenoparietal Stuture
Mandible Parts
8

- Head
- Chondylar Process
- Ramus
- Angle
- Body
- Coronoid Process
- Mental protuberance
- Mandibular Foramen
Cranial Fossae
- Anterior
- Middle
- Posterior
- Frontal
- Temporal
- Occipital
Cribiform plate
Foramen for 1
- Bone
- Cranial Fossa
- Features
- Afferents to olfactory bulb from Nasal conchae
- Ethmoid
- Anterior
- Crista galli
Optic Canal
Foramen for 2
- Bone
- Cranial Fossa and location
- Features
- Optic nerve
- Ophthalmic artery
- Sphenoid
- Middle
- Combines with inputs of orbital fissure
Orbital Fissure
Foramen for 5
Bone
Cranial Fossa
- Oculomotor Nerve
- Abducent
- Ophthalmic division of trigeminnal
- Trochlear
- Ophthalmic vein
Between lesser and greater wings of the sphenoid
Middle
Foramen rotundum
- Foramen for 1
- Bone
- Cranial Fossa
- Maxilliary division of trigeminal
- Anteroinferior sphenoid
- Middle Fossa
Foramen Ovale
Foramen for 2
- Bone
- Cranial Fossa
- Features
- mandibular nerve
- Lesser Petrosal Nerve
Posterior Sphenoid
Middle
Oval shaped, Posterolateral to Foramen rotundum
Foramen Spinosum
- Foramen for 2
- Bone
- Cranial Fossa
- Features
- Middle meningeal artery
- Middle Meningeal Vein
- Sphenoid
- Middle fossa
- Lateral to the foramen ovale.
Foramen Lacerum
Foramen for 2
- Bone
- Cranial Fossa
- Features
- Internal carotid PASSES OVER IT
- Greater and Deep Petrosal nerve: Sypmathetics and Parasympathetics respectively
- Multiple, inc. Medial Pterygoid plate and Petrous temporal bone.
- Middle fossa
- Triangular internal end of carotid canal
Jugular Foramen
Foramen for 4
Bone
Cranial Fossa
Features
- Sigmoid sinus and inferior petrosal sinus becoming Internal jugular
- Glossopharyngeal
- Vagus
- Accessory
- Between Petrous temporal and Occipital bones
- Posterior Fossa
- Divided into anterior and posterior part.
Internal Auditory Meatus
Foramen for 3
- Bone
- Cranial Fossa
- Facial Nerve (Exits via facial canal and styloid foramen)
- Vestibulocochlear
- Labyrinthine artery
- Central Posterior petrous temporal.
- Posterior fossa
Hypoglossal Canal
Foramen for 1
- Bone
- Cranial Fossa
- Hypoglossal Nerve
- Occipital
- Posterior Fossa
Skull’s Blood Supply and route
3
- Internal carotids enter carotid canals, entering the foramen lacerum of the skull
- Vertebral arteries enter via the foramen Magnum
- Middle Meningeal arteries enter via the foramen spinosum.
Skull’s venous drainage
Cranial Venous sinuses groove the inner surface of the skull and the inferior petrosal and sigmoid sinuses converge on the jugular foramen. Thence, the internal jugular
Vertebral veins drain the occipital sinus.
The Oflactory nerve rests on
the cribiform plate of the ethmoid
The Optic nerve enters
The orbit via the optic canal
The Oculomotor nerve exits via
the superior opthalmic fissure
The Trochlear Nerve exits via
the superior opthalmic fissure
The Ophthalmic division of the trigeminal nerve exits via
the superior opthalmic fissure
The Abducent nerve exits via the
the superior opthalmic fissure
The Trigeminal nerve routes
3
- Ophthalmic nerve: superior orbital fissure
- Maxilliary : Foramen rotundum
- Mandibular : Foramen ovale
Facial nerve exits via
3
- Internal autitory Meatus
- Facial Canal
- Stylomastoid foramen
Vestibulochoclear exits via
Internal auditory meatus
Glossopharyngeal exits via
Jugular foramen
Vagus exits via
Jugular foramen
Acessory exits via
Jugular foramen
Hypoglossal exits Via
Hypoglossal foramen
Fontanel between Frontal, Alisphenoid, Temoral and Parietal
Anterolateral Fontanel
Neonates’ temporal-parietal stuture
Squamous Stuture
The Fontanels medial and Lateral to the Lambdoid stuture
2
- Occipital/posterior Fontanel
- Posterolateral Fontanel
The stuture dividing the frontal bones
Metopic stuture
Anterolateral Fontanel
Fontanel between Frontal, Alisphenoid, Temoral and Parietal
Squamous Stuture
Neonates’ temporal-parietal stuture
- Occipital/posterior Fontanel
- Posterolateral Fontanel
The Fontanels medial and Lateral to the Lambdoid stuture
2
Metopic stuture
The stuture dividing the frontal bones
- How many bones in the Skull?
- How Many unpaired?
- How Many Paired?
- 29
- 7
- 11
Unpaired skull bones
7
- Frontal
- Occipital
- Sphenoid
- Ethmoid
- Vomer
- Mandible
- Hyoid
Paired skull bones
11
- Parietal
- Temporal
- Zygomatic
- Maxilla
- Palatine
- Nasal
- Inferior Nasal Concha
- Lacrimal
- Malleus
- Incus
- Stapes
- Neurocranium / Dermocranium
- Viscerocranium
- Chondrocranium
Developmental precursors
- Mixed. Parietals are Mesoderm, the rest is neural crest
- Neural crest
- Mesoderm (the first somites are part of the occipital bone)
Mastoid Process
Process of the temporal bone inferior to the styloid process.
Occipital Chondyles
Join with neck
Internal nares
Fossae Lateral to the Vomer and hamulus, and medial to the zygomatic arch.
Hard Palate is made of
- Anterior 1/3 Made of the Palatine process of maxilla, divided anteriorly by the incisive foramen
- Posterior 2/3: the palatine bones.
Histology of the skull bones
3
Surrounded by periosteum (hard membranous layer)
The inner and outer tables are formed fo copact bone
Inside the inner and outer tables is a dipole of cancellous bone containing red bone marrow
Stutures are
- Fibrous joints: they “interdigitate”
- They allow anjoining elements to grow
- While holding the skull securely together
The Styloid and Hyoid are connected by the
sylohoid ligament
sylohoid ligament
The Styloid and Hyoid are connected by the
The Tip of the epiglottis is located
Superior to the Hyoid
air sinuses bones
- Sphenoid
- Frontal
- Ethmoid
- Maxilla
Have what in common?
After birth, canges in the skull include
7
- Growth of bone and stutures
- Closure of fontanels
- Enlargement of cranial Sinuses
- Development of muscle points
- Development of mandibles and enlargement of teeth
- closure fo mid-frontal stuture
- Development of auditory tube
How many air sinuses
5
Muscles of facial Expression
Controlled by CN7
- Temporalis
- Orbicularis Oculi
- Orbicularis Oris
- Alaeque Nasii
- Buccinator
- Levator Labii Superioris
- Zygomaticus
- Depressor labii Oris
- Depressor Anguli Oris
- Levator Anglularis Oris

- Temporalis
- Orbicularis Oculi
- Orbicularis Oris
- Alaeque Nasii
- Buccinator
- Levator Labii Superioris
- Zygomaticus
- Depressor labii Oris
- Depressor Anguli Oris
- Levator Anglularis Oris
Other Muscles of the face
3
- Auricularis
- Platysma (mandible to clavicle)
- Scalp muscles (occipitofrontalis)
From frontal to Nuchal Line
Mostly Membranous.
Scalp Layers
5
- Skin
- Connective Tissue
- Apneurosis of Occipitofrontalis Muscle
- Loose Connective tissue
- Periosteum
* They spell Scalp