Skull Review

Internal view

Guess the location of the anatomical structure (mouse over to see the answer)
Cribriform plate
Optic Canal
Dorsum Sella
Jugular Foramen
Foramen Rotundum
Frontal sinus
Petrous Part of Temporal bone
Posterior Clinoid Process
Foramen Magnum
Groove for Transverse Sinus
Crista galli
Superior Orbital Fissure
W Foramen cecum
Squamous Part of Temporal Bone
Anterior Cranial Fossa
Sella Turcica
Anterior Clinoid Process
Foramen Ovale
Chiasmatic Groove
Foramen Spinosum
Posterior Cranial Fossa
Hypoglossal Canal
Internal Acoustic Meatus
Lesser Wing of Spnenoid
Foramen Lacerum

1. Frontal Sinus

The mucous membrane in this sinus is innervated by the supraorbital nerve and supplied by the supraorbital artery and anterior ethmoidal artery.

2. Foramen Cecum

the point of attachment of the thyroglossal duct.

3. Crista Galli (Latin: "crest of the cock")

The point where the falx cerebri attaches anteriorly to the skull.

4. Cribriform Plate

The part of the ethmoid bone; it is perforated by foramina for the passage of the olfactory nerves (CN I)

5. Anterior Cranial Fossa

The floor of the fossa: is formed by the orbital plates of the frontal bone, the cribriform plate of the ethmoid bone, and the small wings and front part of the body of the sphenoid; it is limited behind: by the posterior borders of the small wings of the sphenoid and by the anterior margin of the chiasmatic groove

6. Lesser Wing of Sphenoid

The medial end of the lesser wing attached to the body by means of two pedicles, thus forming the optic canal. The wing itself forms the superior margin of the supraorbital fissure.

7. Chiasmatic Groove

The groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity.

8. Sella turcica - "Turkish saddle" (hypophyseal fossa)

saddle-shaped depression in the sphenoid bone

The seat of the saddle is known as the hypophyseal fossa which holds the pituitary gland

9. Dorsum Sella

Forms the posterior part of the Sella turcica. The dorsum sella is terminated laterally by the posterior clinoid processes.

10. Optic Canal

transmits the optic nerve and ophthalmic artery (with accompanying sympathetic nerve fibers) into the orbital cavity. The left and right optic canals are 25mm apart posteriorly and 30mm apart anteriorly. They are funnel-shaped (narrowest anteriorly). The optic foramen is the opening to the optic canal.

11. Anterior Clinoid Process

Formed by the medial end of the posterior border of the sphenoid bone. It gives attachment to the tentorium cerebelli.

12. Foramen Rotundum

a circular hole in the sphenoid bone that connects the middle cranial fossa and the pterygopalatine fossa.

The maxillary nerve V2 passes through it.

13. Foramen Ovale

a hole in the greater wing of the sphenoid bone in the middle cranial fossa. Transmits the mandibular nerve V3, otic ganglion, accessory meningeal artery, lesser petrosal nerve and emissary veins

14. Foramen Spinosum

an opening in the greater wing of the sphenoid bone, in front of the spine. Transmits the middle meningeal artery,

middle meningeal vein, the nervus spinosus (a recurrent branch from the mandibular nerve V3)

15. Squamous Part of Temporal

Its outer surface is smooth and convex; it affords attachment to the temporalis muscle, and forms part of the temporal fossa; on its hinder part is a vertical groove for the middle temporal artery. The internal surface of is concave; it presents depressions corresponding to the convolutions of the temporal lobe of the brain, and grooves for the branches of the middle meningeal vessels.

16. Petrous Part of Temporal bone

is pyramidal and is wedged in at the base of the skull between the sphenoid and occipital. Directed medially, forward, and a little upward, it presents for examination a base, an apex, three surfaces, and three angles, and contains, in its interior, the essential parts of the organ of hearing.

17. Groove for Transverse Sinus

A groove on the inner surface of the occipital bone marking the course of the transverse sinus; the tentorium is attached to its margins.

18. Posterior Cranial Fossa

The posterior cranial fossa is part of the intracranial cavity, located between the foramen magnum and tentorium cerebelli. This is the most inferior of the fossae. It houses the cerebellum, medulla and pons. Anteriorly it extends to the apex of the petrous temporal. Posteriorly it is enclosed by the occipital bone. Laterally portions of the squamous temporal and mastoid part of the temporal bone form its walls.

19. Foramen Magnum

A large opening in the occipital bone in the base of the skull. The medulla oblongata (an extension of the spinal cord) enters and exits the skull vault through it. Also transmits the Spinal Accessory nerve (CN XI), vertebral arteries, the anterior and posterior spinal arteries, the membrana tectoria and alar ligaments.

20. Hypoglossal Canal

A bony canal in the occipital bone. Transmits hypoglossal cranial nerve (CN XII)

21. Jugular Foramen

is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone. It may be subdivided into three compartments, each with their own contents.

22. Internal Acoustic Meatus

a canal in the temporal bone. The opening to the internal acoustic meatus is located inside the cranial cavity, near the center of the posterior surface of the temporal bone. It is short (about 1 cm) and runs laterally into the bone. At its end are the openings for three different canals, one of which is the facial canal. It does not transmit sound waves. It instead transmits the facial (CN VII) and vestibulocochlear nerves (CN VIII) and the labyrinthine artery (an internal auditory branch of the basilar artery). The facial nerve travels through the facial canal, eventually exiting the skull at the stylomastoid foramen.

23. Posterior Clinoid Process

Part of the sphenoid bone, The posterior clinoid processes deepen the sella turcica, and give attachment to the tentorium cerebelli

24. Foramen Lacerum

a triangular hole in the base of the skull located at the base of the medial pterygoid plate. The foramen is mostly filled with cartilage. Some nerves, arteries, and veins do pass through the cartilage plug of the foramen lacerum: the artery of pterygoid canal, the nerve of pterygoid canal, and some venous drainage.

25. Superior Orbital Fissure

a foramen in the skull, although strictly it is more of a cleft, lying between the lesser and greater wings of the sphenoid bone. Transmits:

-         superior and inferior divisions of oculomotor nerve (III)

-         trochlear nerve (IV)

-         lacrimal, frontal and nasociliary branches of ophthalmic nerve (V1)

-         abducens nerve (VI)

-         superior and inferior divisions of ophthalmic vein

-         sympathetic fibers from cavernous plexus

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