Infratemporal Fossa Flashcards
What are five features of the temporal region?
- Pterion
- Temporal lines
- Zygomatic arch
- Infratemporal crest
- Temporal fascia over the temporalis muscle
What are the posterior and superior boundaries of the temporal fossa?
Temporal lines
What is the anterior boundary of the temporal fossa?
Frontal and zygomatic bones
What is the lateral boundary of the temporal fossa?
Zygomatic arch
What is the inferior boundary of the temporal fossa?
Infratemporal crest
What is the lateral boundary of the infratemporal region?
Ramus of mandible
What is the medial boundary of the infratemporal region?
Lateral pterygoid plate
What is the anterior boundary of the infratemporal region?
Posterior aspect of maxilla
What is the posterior boundary of the infratemporal region?
Tympanic portion, mastoid process, styloid process
What is the superior boundary of the infratemporal region?
Inferior surface of greater wing of sphenoid
What is the inferior boundary of the infratemporal region?
Medial pterygoid attachment near the mandibular angle
What nerves can be found in the infratemporal fossa?
- Mandibular V3 nerves (inferior alveolar, lingual, buccal)
- Chorda tympani
- Otic ganglion
What are the primary muscles of mastication?
- Temporalis
- Masseter
- Lateral pterygoid
- Medial pterygoid
Origin and insertion of temporalis
O: Superior temporal line
I: Coronoid process
What are the actions of temporalis?
Elevate the mandible (close jaw), retrude chin, lateral movements
Origin and insertion of masseter
O: Zygomatic bone/arch
I: Angle and ramus of mandible
What are the actions of the masseter?
Elevate the mandible (close jaw), protrude chin, retrude chin, lateral movements
Which muscles of mastication are innervated by anterior trunk of mandibular nerve (CN V3)?
Temporalis, masseter, lateral pterygoid
What innervates temporalis?
Anterior trunk of mandibular nerve via deep temporal branches
What innervates masseter?
Anterior trunk of mandibular nerve via masseteric nerve
What innervates lateral pterygoid?
Anterior trunk of mandibular nerve via lateral pterygoid nerve
What innervates medial pterygoid?
Main trunk of mandibular nerve via medial pterygoid nerve
What are the suprahyoid muscles?
- Digastric
- Stylohyoid
- Mylohyoid
- Geniohyoid
Origin and insertion of digastric
O: Base of cranium
I: Hyoid bone
Origin and insertion of stylohyoid
O: Styloid process
I: Hyoid bone
Origin and insertion of mylohyoid
O: Medial body of mandible
I: Hyoid bone
Origin and insertion of geniohyoid
O: Anterior body of mandible
I: Hyoid bone
What are the actions of the suprahyoid muscles?
Depresses mandible against resistance when infrahyoid muscles fix or depress hyoid bone
What innervates digastric?
Facial and mandibular nerves
What innervates stylohyoid?
Facial nerve (CN VII)
What innervates mylohyoid?
Mandibular nerve (CN V3) gives off nerve to mylohyoid
What innervates geniohyoid?
Nerve to geniohyoid (C1-C2)
What are the infrahyoid muscles?
- Omohyoid
- Sternohyoid
- Sternothyroid
- Thyrohyoid
What are the actions of infrahyoid muscles?
Fixes or depresses hyoid bone
Origin and insertion of omohyoid
O: Scapula
I: Hyoid bone
Origin and insertion of sternohyoid
O: Manubrium of sternum
I: Hyoid bone
Origin and insertion of sternothyroid
O: Manubrium of sternum
I: Thyroid cartilage
Origin and insertion of thyrohyoid
O: Thyroid cartilage
I: Hyoid bone
Which infrahyoid muscles are innervated by ansa cervicalis from cervical plexus (C1-C3)?
- Omohyoid
- Sternohyoid
- Sternothyroid
What innervates thyrohyoid?
C1 (via hypoglossal nerve CN XII)
What is the main action of platysma?
Depresses mandible against resistance
What is the inferior attachment/origin of platysma?
Subcutaneous tissue of infraclavicular and supraclavicular regions
What is the superior attachment/insertion of platysma?
Base of mandible, skin of cheek and lower lip, angle of mouth (modiolus), and orbicularis oris
What innervates platysma?
Cervical branch of facial nerve (CN VII)
What are five structures found in the temporomandibular joint?
- Mandibular fossa of temporal bone
- Head (condylar process) of mandible
- Articular disc
- Stylomandibular ligament
- Sphenomandibular ligament
What muscle does the articular disc of the temporomandibular joint attach to?
Lateral pterygoid muscle
Pterygoid venous plexus is between…
temporalis and lateral pterygoid muscles
The pterygoid venous plexus anastomoses with…
facial vein, cavernous sinus, and maxillary vein
The maxillary artery is a terminal branch of…
external carotid artery
What are the three parts of the maxillary artery?
- Mandibular
- Pterygoid
- Pterygo-palatine
Where is the mandibular part of the maxillary artery?
Horizontal along lower border of lateral pterygoid and deep (medial) to neck of condylar process of mandible
What are the branches off the mandibular part of the maxillary artery?
- Deep auricular artery
- Anterior tympanic artery
- Middle meningeal artery
- Inferior alveolar artery
Where is the pterygoid part of the maxillary artery?
Ascends adjacent (superficial or deep) to lateral pterygoid
What are the branches off the pterygoid part of the maxillary artery?
- Artery to masseter
- Deep temporal arteries
- Pterygoid arteries
- Buccal artery
Where is the pterygo-palatine part of the maxillary artery?
Through pterygomaxillary fissure into pterygopalatine fossa
What are the branches off the pterygo-palatine part of the maxillary artery?
- Posterior superior alveolar artery
- Infraorbital artery
- Artery of pterygoid canal
- Pharyngeal branch
- Descending palatine artery
- Sphenopalatine artery
Where do the following branch from:
- Deep auricular artery
- Anterior tympanic artery
Mandibular part of maxillary artery
Where do the following branch from:
- Middle meningeal artery
- Inferior alveolar artery
Mandibular part of maxillary artery
Where do the following branch from:
- Artery to masseter
- Deep temporal arteries
Pterygoid part of maxillary artery
Where do the following branch from:
- Pterygoid arteries
- Buccal artery
Pterygoid part of maxillary artery
Where do the following branch from:
- Posterior superior alveolar artery
- Infraorbital artery
Pterygo-palatine part of maxillary artery
Where do the following branch from:
- Artery of pterygoid canal
- Pharyngeal branch
Pterygo-palatine part of maxillary artery
Where do the following branch from:
- Descending palatine artery
- Sphenopalatine artery
Pterygo-palatine part of maxillary artery
What is the terminal branch of the maxillary artery?
Sphenopalatine artery branching from pterygo-palatine part
The mandibular nerve (V3) descends through ___ into ___
through foramen ovale into infratemporal fossa
The auriculotemporal nerve encircles which artery?
Middle meningeal artery
What does the auriculotemporal nerve sense?
Auricle, temporal region, and TMJ
What does the auriculotemporal nerve branch from?
Mandibular nerve (V3)
The inferior alveolar nerve enters…
mandibular foramen
What does inferior alveolar nerve sense?
Lower teeth
What does the nerve to mylohyoid branch from?
Inferior alveolar nerve
What does the inferior alveolar nerve branch from?
Mandibular nerve (V3)
What is the terminal branch of the inferior alveolar nerve?
Mental nerve
What does the lingual nerve branch from?
Mandibular nerve (V3)
Where is the lingual nerve in relation to inferior alveolar nerve?
Anterior to inferior alveolar nerve
What does the lingual nerve sense?
Anterior 2/3 of tongue, floor of mouth, and lingual gingivae
The lingual nerve is joined by ___ to sense taste for anterior 2/3 of tongue and provide preganglionic parasympathetic fibers to submandibular and sublingual salivary glands
chorda tympani nerve (VII)
What does the buccal nerve branch from?
Mandibular nerve (V3)
What is the function of the buccal nerve?
Sensory for cheek
Motor nerves to masseter, tensor veli palatini, medial pterygoid, lateral pterygoid, and temporalis all branch from…
mandibular nerve (V3)
