Bones of the skull

Every question, with the answer explained

The full set, for revision or for reading straight through. The correct answer is marked, and the explanation says why.

1. 1. How many bones form the adult skull?

   • 12
   • 22
   • 30
   • 8

   22. 22 — eight cranial bones enclosing the brain and fourteen facial bones. Only the mandible moves freely; the rest are joined by sutures.

2. 2. Which bone forms the forehead?

   • The parietal bone
   • The frontal bone
   • The occipital bone
   • The temporal bone

   The frontal bone. The frontal bone forms the forehead and the roof of the orbits. It also contains the frontal sinuses.

3. 3. Which bone contains the foramen magnum?

   • The occipital bone
   • The sphenoid bone
   • The ethmoid bone
   • The frontal bone

   The occipital bone. The foramen magnum in the occipital bone is the large opening through which the brainstem becomes the spinal cord.

4. 4. The suture between the two parietal bones is the:

   • Coronal suture
   • Sagittal suture
   • Lambdoid suture
   • Squamous suture

   Sagittal suture. The sagittal suture runs front to back between the parietal bones. The coronal separates frontal from parietal, and the lambdoid separates parietal from occipital.

5. 5. Which bone is described as butterfly-shaped and articulates with almost every other cranial bone?

   • The sphenoid
   • The vomer
   • The zygomatic
   • The nasal

   The sphenoid. The sphenoid sits centrally at the base of the skull. Its sella turcica houses the pituitary gland.

6. 6. The cheekbone is properly called the:

   • Maxilla
   • Zygomatic bone
   • Mandible
   • Lacrimal bone

   Zygomatic bone. The zygomatic bone forms the prominence of the cheek and part of the lateral orbit. The maxilla is the upper jaw.

7. 7. Which structure passes through the optic canal?

   • The facial nerve
   • The optic nerve and ophthalmic artery
   • The trigeminal nerve
   • The internal jugular vein

   The optic nerve and ophthalmic artery. The optic canal in the sphenoid transmits the optic nerve and the ophthalmic artery from the cranial cavity into the orbit.