H&N 2: Skull & Intracranial Region Flashcards
What is the function of the cranium?
Protects the brain and sensory organs
Which 2 parts form the cranium?
- Neurocranium
2. Viscerocranium
What is the neurocranium made up of?
- skull cap (calvaria)
- basicranium
- intracranial region inner surface of the base of the skull
What is the basicranium?
- when you remove the brain and turn the skull upside down
What is the intracranial region?
- skull when brain is removed
List the bones the neurocranium is made up of
Singular bones: 1. Frontal 2. Ethmoidal 3. Sphenoidal 4. Occipital Paired bones: 5. Temporal 6. Parietal
What does the viscerocranium comprise of?
- facial bones in the ant. part of the cranium:
- bones surrounding mouth, forming the upper and lower jaws
- nose, nasal cavity + orbit
List the bones of the viscerocranium
Singular: - mandible - vomer Paired: - maxillae - inf. nasal conchae (aka turbinates) - zygomatic - palatine - nasal - lacrimal
What is the function of nasal tubrinates?
circ air and warms it up
Which bone is sup. + middle nasal conchae part of?
Ethmoid
Which joint is the only moveable joint of the cranium?
temporomandibular joint with articulates with the cranial base
Which bones form the nasal septum?
- perpendicular plate of ethmoid bone
- vomer
What is the sig of the pterion?
- v. fragile area where all bones join together
- skull thin around temples around the pterion and middle meningeal artery which can lead to fatal injury as a result of trauma
List the cranial bones
- Frontal
- Parietal
- Occipital
- Temporal
- Sphenoid
- Ethmoid
What is the frontal bone?
- forms part of top of head, forehead and the roof of the orbits
What is the parietal bone?
- div approx. mid-sagitally
- forms lat. walls and roof of cranium
What is the occipital bone?
- reps post. region of skull
What are the temporal bones?
- form inf. lat. walls + part of floor of the cranium
What is the sphenoid bone?
- shaped like a butterfly/bat
- unites with the cranial (neurocranium) and facial (viscerocranium) bones
- articulates with every other cranial bone + palatine, zygomatic, maxillae + vomer
What is the ethmoid bone?
- pos between the orbits
- forms anteromedial floor of cranium
- roof of nasal cavity
- part of medial wall of each orbit
- part of nasal septum
What is the body of the sphenoid bone like?
- air-filled
List the facial bones
- Maxilla
- Palatine
- Zygomatic
- Lacrimal
- Nasal
- Vomer
- Inf. nasal conchae
- Mandible
What is the maxilla?
- forms central part of facial skeleton
- both unite to form upper jaw supporting the upper teeth
What are the palatine bones?
- small bones with a distinct L shape
- form part of the hard palate, nasal cavity + eye orbit
What are the zygomatic bones?
- cheekbones
- form part of the lat. wall of each orbit and the cheeks
What are the lacrimal bones?
- smallest bones in the skull
- form part of the medial wall of each orbit
- have a groove that provides a passageway for each tear duct which drains tears into the nasal cavity
What are the nasal bones?
- form the bridge of the nose
- lat. side articulates with the medial edge of the maxilla - often fractured by blows to the nose
What is the vomer?
- forms inf. post. part of nasal septum
- art along its midline with both maxilla and palatine bones
- its wings art sup. with sphenoid bone and perpendicular plate of ethmoid forming together the bony nasal septum
What is the inf. nasal conchae?
- in lat. wall of nasal cavity
- help create turbulence in inhaled air
- has sup. + middle counterparts that are part of the ethmoid bone (but these are sep bones)
What is the mandible?
- forms entire lower jaw
- supports lower teeth
- provides attachment for muscles of mastication
What are the skull air sinuses?
- spaces that containing air + mucus which drains through them + out of nose
List the 4 main pairs of sinus cavities in the skull
- Frontal
- Ethmoid
- Sphenoid
- Maxillary
What is the sig of infection in skull air sinuses?
- infection in frontal, ethmoid + sphenoid drain down bc of gravity
- but infection in maxillary drains against gravity - need antibiotics to clear infection
