• 13 parts
  • Checked October 2026

Cavities of the Skull Labeled on Two Cuts

The hollow spaces of the skull named on two cuts; press Quiz me to find each one.

Cavities of the Skull Labeled on Two Cuts

Name Date

Tap any part to read, rename or leave it out

1 2 3 4 5 6 7 8 9 10 11 12 13
More options

Write the name of each numbered part.Answer key

  1. Cranial cavity
  2. Orbit (eye socket)
  3. Nasal cavity
  4. Oral cavity (mouth)
  5. Maxillary sinus
  6. Ethmoid air cells
  7. Nasal septum
  8. Nasal conchae
  9. Frontal sinus
  10. Sphenoidal sinus
  11. Anterior cranial fossa
  12. Middle cranial fossa
  13. Posterior cranial fossa

Drawn for this site on 2026-10-01 from plain geometry. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a part is answered.

Next step Next: the bones round these spaces, the whole skull

All 13 parts on the diagram

Show the list

Cut across 8

  1. Cranial cavity The space inside the skull that holds the brain. Its floor is in three steps, the cranial fossae.
  2. Orbit (eye socket) The socket that holds the eyeball. The frontal bone is its roof, and the maxilla below separates it from the maxillary sinus.
  3. Nasal cavity The air space behind the nose. It is much narrower above than below, and the paranasal sinuses open into it.
  4. Oral cavity (mouth) The mouth, the space under the hard palate. The palate separates it from the nasal cavity above.
  5. Maxillary sinus The largest paranasal sinus. It lies in the maxilla, below the orbit and beside the nasal cavity.
  6. Ethmoid air cells Many small air spaces inside the ethmoid bone. They lie between the nasal cavity and the orbit and form the ethmoidal sinus.
  7. Nasal septum The thin upright wall that splits the nasal cavity in two. Its bone is mainly the perpendicular plate of the ethmoid and the vomer.
  8. Nasal conchae Curled shelves of bone on each side wall of the nasal cavity. There are three on a side: superior, middle and inferior.

Cut down the middle 5

  1. Frontal sinus An air space inside the frontal bone, above the eyes. It is the highest of the paranasal sinuses.
  2. Sphenoidal sinus An air space in the body of the sphenoid. It lies just under the sella turcica and opens into the nasal cavity.
  3. Anterior cranial fossa The front and shallowest step of the cranial floor. It lies over the orbits and nasal cavity and holds the frontal lobes.
  4. Middle cranial fossa The middle step of the cranial floor, deeper than the front one. It holds the temporal lobes and the pituitary gland.
  5. Posterior cranial fossa The back and deepest step of the cranial floor. It holds the cerebellum and brainstem, and the foramen magnum opens in its floor.

How this list was compiled: Every name and detail line was checked on 2026-10-01 in at least two of these, in our own words: Henry Gray, Anatomy of the Human Body (1918, public domain), The Interior of the Skull; TeachMeAnatomy, The Paranasal Sinuses, The Nasal Cavity, The Bony Orbit, The Oral Cavity and the Cranial Fossa pages; Wikipedia, Paranasal sinuses, Cranial cavity, Orbit, Nasal cavity. Licence: own work

The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work

How it works

The cavities of the skull labeled on two cuts, across the face and down the middle. In the quiz every part you find stays written in on the drawing.

Read the full guide

Cut across

You look at the skull from the front, cut through the eye sockets. The cranial cavity fills the top. Under it sit the two orbits, with the nasal cavity between them and the mouth below. The ethmoid air cells are stacked between the nose and each orbit, and a maxillary sinus sits in each cheek.

Cut down the middle

The face is on the left. The frontal sinus is in the forehead bone and the sphenoidal sinus is in the block of bone behind the nose. The floor of the cranial cavity steps down from front to back: anterior, middle and posterior cranial fossa.

  • Each paranasal sinus is named for its bone: frontal, ethmoid, sphenoid, maxilla.
  • The fossae run front to back, and each is deeper than the one before.

Questions and answers

What are the cavities of the skull?

The cranial cavity, which holds the brain, the two orbits, the nasal cavity, the mouth, and the four pairs of paranasal sinuses. The middle ear cavity lies inside the temporal bone, on neither cut drawn here.

What are the four paranasal sinuses?

The frontal, ethmoidal, sphenoidal and maxillary sinuses, each named for the bone it lies in. All four are air spaces that open into the nasal cavity. The maxillary sinus is the largest.

What are the three cranial fossae?

Three steps in the cranial cavity's floor. The anterior fossa holds the frontal lobes, the middle fossa the temporal lobes and the pituitary gland, and the posterior fossa the cerebellum and brainstem.

Which bone forms the roof of the orbit?

Mostly the frontal bone, which divides the orbit from the anterior cranial fossa above it. The floor of the orbit is mostly maxilla, with the maxillary sinus beneath it.

More quizzes

Show 7 more

Browse Human Body Quizzes