What are the 4 different major skull cavities?
1. Middle and Inner Ear (lateral aspect of cranial base)
2. Nasal Cavity (in and posterior to nose)
3. Orbits (house eyeballs)
4. Air-filled Sinuses (in some bones around nasal cavity)
the gap between the ethmoidal bulla and the
- between eyes, part of nasal septum
- Crista Galli
- Cribiform Plate
- Olfactory Foramina
- Perpendicular Plate
- Orbital Plate
- Superior Nasal Concha
- Middle Nasal Concha
- Ethmoid Sinuses
small lateral expansion of the ethmoid bone from the anterior aspect of the crista galli on each side that articulates with the frontal bone and forms the foramen cecum?
Ala (wing) of Crista Galli
It fits into the ethmoidal notch of the frontal bone and supports the olfactory lobes of the cerebrum, being
pierced with numerous openings for the passage of the olfactory nerves; it contributes to the roof of the
- attachment for membranes of brain
green part pointed at by the arrow and the pink ones below
Middle Nasal Concha of Ethmoid and Inferior Nasal Concha
note superior cocha in pic below, superior nasal concha not visible from anterior view in completely skull.
middle and superior nasal concha are part of ETHMOID bone/cranial skull
inferior nasal conchae are pair of bones extending from maxilla and palatine, and they are considered FACIAL bones
Means funnel in greek
a bulging of the inner wall of the ethmoidal
labyrinth in the middle meatus of the nose
inferior nasal meatus
inferior nasal concha
middle nasal meatus
middle nasal concha
opening to the pharagealtympanic/auditory tube, or "eustachian tube"
this tube connects the nasopharynx to the middle ear, and this is how you can equalize pressure during scuba diving or flying by holding your nose and inflating the nasal cavity, or swallowing or yawning. small amounts of air are allowed to pass through the tube to equalize with the pressure in the atmosphere.
11, and it goes where?
Goes from above the superior nasal meatus to the sphenoid sinus
superior nasal meatus
Holes in part C
- AKA cribriform foramina, tiny holes to transmit the olfactory nerves
a sickle-shaped process of bone on the medial
wall of the ethmoidal labyrinth below the middle nasal concha; it joins with the ethmoidal
process of the inferior nasal concha and partly closes the orifice of the maxillary sinus
Not just the bone, but the specific part
- lateral surface of ethmoid, medial wall of orbit
- superior portion of nasal septum
Perpendicular plate of ethmoid has three borders: Anterior, posterior, and inferior.
each side interacts with what bones?
a. The anterior border articulates with the spine of the frontal bone and the crest of the nasal bones.
b. The posterior border articulates by its upper half with the sphenoidal crest, and the lower half interacts with the
c. The inferior border is thicker than the posterior, and serves for the attachment of the septal
cartilage of the nose.
ethmoidal air cells
- an outward bulging of the lateral wall of the nasal cavity in the middle nasal meatus
- caused by the bulging of the largest ethmoidal air cell
3, 4, 5
superior, middle, and inferior nasal concha
6 is what? location?
opening of the nasolacrimal duct to the lacrimal gland
located under the inferior nasal concha
7 is what? location?
opening of the maxillary sinus, under the middle nasal concha
The hyoid bone which can be included in the bony skeleton of the skull, is not directly connected to any bone in the body, it is a U-shaped bone lying between the mandible and the larynx, suspended from the styloid process by
ligaments & muscles.