Anatomical Spaces Of The Head And Neck I&II Flashcards
What are the 2 classes of bony spaces in the head?
Extracranial and intracranial
What are the 3 extracranial bony spaces of the head?
Temporal fossa, infratemporal fossa, pterygopalatine fossa
Where is the temporal fossa?
A shallow depression on the side of the skull
What are the boundaries of the temporal fossa?
Superior and posteriorly: superior temporal line
Inferiorly: zygomatic arch
Anteriorly: frontal process of zygomatic and zygomatic process of frontal bone
Medially: frontal, parietal, temporal, sphenoid
Laterally: temporal fascia
Where does the pterion sit?
In the temporal fossa
Muscles of the temporal fossa
Origin of the temporalis
Blood vessels of the temporal fossa
Supplies by superficial temporal artery, a terminal branch of the external carotid artery
Nerves of the temporal fossa
Mandibular nerve CNV3, anterior and posterior branches of deep temporal nerve, auriculotemporal nerve, zygomaticotemporal nerve, temporal branches of facial nerve
What is the location of the infratemporal fossa?
Lies below the middle cranial fossa, medial and deep to the zygomatic arch, behind the maxilla.
A deeper continuation of the temporal fossa.
Boundaries of the infratemporal fossa
Superiorly: infratemporal surface of greater wing of sphenoid
Inferiorly: alveolar border of maxilla (or nothing)
Medially: lateral pterygoid plate
No lateral border.
Muscles of the infratemporal fossa
Lower part of temporalis, lower parts of medial and lateral pterygoids
Nerves of the infratemporal fossa
Mandibular nerve CNV3 and most of its branches: auriculotemporal, buccal, lingual, inferior alveolar nerve
Optic ganglion
Arteries of the infratemporal fossa
Maxillary artery, including middle meningeal artery
Superficial temporal artery (branch of ECA)
Veins of the infratemporal fossa
Pterygoid venous plexus
Direct communications of the pterygoid venous plexus
Cavernous sinus
Superior ophthalmic vein
What does venostasis around the pterygoid venous plexus cause?
Creates a lack of movement around the oral region. Produces the yawning reflex. Triggered to produce movement of the jaw.
Openings of the infratemporal fossa
Foramen spinous, foramen ovale, alveolar canal, inferior orbital fissure, ptergymaxillary fissure
How do pathologies evolve in the infratemporal fossa?
It is a potential anatomical space. Pathologies can evolve without detection, so when they become symptomatic they are likely to be advanced.
Describe a mandibular nerve block
Anaesthetic injected to the nerve as it enters the infratemporal - affects the inferior alveolar, lingual, buccal and auriculotemporal nerves
Describe an inferior alveolar nerve block
During dental treatment, anaesthetic is injected around the mandibular foramen on the medial side of the of the mandible. All the mandibular teeth are anaesthetic to the medial side. Skin and mucous membrane of lower lip also anaesthetised (supplied by mental branch)
Where is the location of the pterygopalatine fossa?
Anatomical space created at the interval between the Neurocranium and viscerocranium. Inverted pyramid shape. Behind and below the ocular orbit. Found between bones on the lateral aspect of the skull immediately posterior to the maxilla.
Why is the pterygopalatine fossa a weakness of the face?
Because the embryology of the cranium and facial skeleton are different, so can come apart with enough energy. Can also be a major route of spread of infection and metastases.
Boundaries of the pterygopalatine fossa
Anteriorly: posterior surface of maxilla
Posteriorly: pterygoid process
Medially: perpendicular plate of palatine bone
Laterally: pterygomaxillary fissure
Communications of the pterygopalatine fossa
With infratemporal fossa via the pterygomaxillary fissure
With middle cranial fossa via foramen rotundum
With nasal cavity via the sphenopalatine foramen
With orbital cavity via the inferior orbital fissure
With the palatine bone via greater palatine canal
With nasopharynx via the pharyngeal and pterygoid canals