Head & Neck Flashcards
Neurocranium bones?
- frontal
- parietal
- occipital
- temporal
- sphenoid
- ethmoid
How many bones in the skull? How many ‘associated’ bones?
-22 bones in the skull, 7 associated bones
Viscerocranium bones?
-mandible
-maxilla
-zygoma
-vomer
-lacrimal
-nasal
-palatine
inferior nasal concha
Calvaria (cranial vault) made up of?
- frontal, parietal & occipital bones
- bones formed by intramembranous ossificiation
- convex shape resists impact
What are fontanelles for?
- allow for passage of head through birth canal & accommodate growth of brain
- cranial bones do not articulate in the newborn
- soft spots (fontanelles)= membrane covered parts of the skull where sutures form, usually exist until about 7-19 months
- bulging or tense fontanelles may= increased intracranial P
What are the 3 cranial fossae?
-anterior, middle, posterior
What is the anterior fossa?
-anterior: frontal bone, crista galli & cribiform plate of ethmoid & lesser wings of sphenoid; contains frontal lobe & CN#1
What is the posterior fossa?
-posterior: sphenoid, temporal & occipital bones; contains occipital lobe, cerebellum, brainstem; number of ‘holes’ namely foramen magnum, hypoglossal canal, jugular foramen & internal auditory meatus
What is the middle fossa?
-middle: sphenoid & temporal bones; contains sella tursica, chiasmic groove, optic canal, superior orbital fissure, foramen rotundum, foramen ovale, foramen spinosum, foramen lacerum & cavernous sinus; structures provide for pituitary, optic chiasm, optic n., internal carotid artery & CNs III, IV, V1, V2 & VI; temporal lob of brains rests in middle fossa
Where can sinuses be found?
- ethmoid
- sphenoid
- maxilla
- frontal
- temporal (mastoid air cells)
- all are potential sites of infection
What does the mandible articulate with?
- temporal bones at the tempomandibular joint
- 1/5 of facial injuries involve mandibular fracture
What does the mandible hold? What n. are the gums and teeth innervated by?
- holds lower row of teeth in gomphosis joint at alveolar processes
- gums/teeth innervated by inferior alveolar n.
Temporomandibular joint is what kind of joint? Between what? Innervated by what n.?
- synovial jt with an articular disc
- articulation is b/w condylar portion of the mandible & mandibular fossa & articular tubercle of temporal bone
- innervated by mandibular branch of trigeminal n.
Hyoid bone is what kind of bone? Suspended from what? Attachment point for what?
- U-shaped bone
- suspended from temporal bone by stylohyoid ligaments from styloid processes of temporal bones
- has a body, 2 lesser cornua, & 2 greater cornua
- only bone in the human body that does not articulate with any other bone
- attachment point for muscles responsible for speech & swallowing
The bony orbit is made up of what bones?
- frontal
- maxillary
- ethmoid
- sphenoid
- lacrimal
- zygomatic
- palantine
Nostrils open up into the?
nasal cavity
The lateral wall of the nasal cavity has?
bumpy projections, conchae (turbinates)
The names of the conchae?
-superior, middle & inferior conchae
Superior & middle are made up of what bones? Inferior?
- superior and middle conchae are part of the ethmoid bone
- inferior conchae are individual bones
Roof of the nasal cavity contains receptors from what nerve?
Olfactory n.
Nostrils separated by?
nasal septum, which consists of perpendicular plate of the ethmoid, vomer, & cartilage; all covered w/mucosa
What are the conchae for?
warm & filter inhaled air, mucosa serves immune function by trapping foreign particles & exposing them to Ag presenting cells
What are the sutures?
- fibrous joints b/w bones of the skull
- coronal: b/w frontal & parietal
- sagittal: b/w parietals
- lambdoidal: b/w parietal & occiput
- squamosal: b/w parietal & temporal
- bregma: jxn of corona & sagittal sutures
- lambda: jxn b/w lambdoidal & sagittal structures
- pterion: jxn of frontal, parietal, temporal & sphenoid bones
- sutural ligs connect the cranial bones that are the remaining, unossified sheets of mesenchyme from intramembranous ossification
Muscles of facial expression?
- sphincter muscles: orbicularis oculi, orbicularis ori
- all other muscles may be considered dilator muscles
- innervated by facial n. (CN VII)
Muscles of mastication?
- temporalis
- masseter
- medial pterygoid
- lateral pterygoid
- all innervated by trigeminal n. (CN V)
- movements of the jaw: elevation, depression, protraction, retraction
Medial ptygoid does what?
elevation & protrusion
Lateral ptygoid does what?
depression & protrusion
Temporalis does what?
elevation & retraction
Masseter does what?
elevation & protraction
What are the two divisions of the anterior neck?
anterior & posterior triangles
What borders the anterior triangle?
sternocleidomastoid, inferior border of the mandible & anterior midline of the neck
What borders the posterior triangle?
sternocleidomastoid, clavicle & trapezius
Muscles of deglutition/speech & nerve?
- digastric, anterior belly (trigeminal)
- digastric, posterior belly (facial)
- mylohyoid (trigeminal)
- sternohyoid (ansa cervicalis)
- omohyoid (ansa cervicalis)
- cricothyroid (vagus)
- thyrohyoid (1st cervical n., via hypoglossal)
- sternothyroid (ansa cervicalis)
The facial nerve exits where and branches into? What does it provide innervation to?
- Exits skull via stylomastoid foramen
- branches into 5 divisions: temporal, zygomatic, buccal, mandibular & cervical
- provides motor innervation to muscles of facial expression
What does the trigeminal nerve provide innervation to? What are the 3 branches?
- sensory innervation to face
- 3 branches, each provides sensation to a separate region of the face
- ophtalmic division (V1), maxillary division (V2) & mandibular division (V3)
What artery supplies the face with blood? Where does it arise from?
- the facial artery
- arises from external carotid artery & travels superiorly around lower border of the mandible towards midline of the face
- superficial temporal artery also arises from external carotid artery ascending to the mandible but anterior to the ear
Where does the facial vein begin & where does it go?
Just under the bony orbit, descends obliquely towards inferiolateral border of the mandible
Where does the facial vein drain to? And what other vein does it communicate with?
- drains to internal jugular vein
- communicates with superior ophthalmic vein & thus deeper into the cavernous sinus
- possible route of infection from face to cranial dural sinus
Lymphatics of the face follow what? Can you normally palpate?
- the major bvs in this area as they drain inferiorly towards the heart
- not normally palpable but may be enlarged in infection or inflammatory states
