Table of Contents

1. What Is the Cranium?

2. Skull Anatomy: Neurocranium vs. Viscerocranium

3. The Eight Cranial Bones

4. Facial Bones of the Skull

5. Major Cranial Sutures and Fontanelles

6. Skull Base & Cranial Fossae

7. Important Foramina and Nerve Pathways

8. Clinical Relevance: Pterion, Fractures, and Surgeries

9. Visual Aids and Study Resources

10. Final Thoughts + More Reading

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1. What Is the Cranium?

The cranium is another name for the skull, especially the part that encloses and protects the brain. The cranium is part of the neurocranium, which includes eight bones fused together by joints known as sutures.

🧩 Want a deeper dive into skull terminology? Check out this full breakdown on cranium vs. skull on MicroMinds.

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2. Skull Anatomy: Neurocranium vs. Viscerocranium

The skull is divided into two main parts:

• Neurocranium: Encases the brain. Includes frontal, parietal, occipital, temporal, sphenoid, and ethmoid bones.

• Viscerocranium (facial skeleton): Includes bones like the maxilla, zygomatic, mandible, and nasal bones.

These regions work together to protect the brain, anchor facial muscles, support sensory structures, and enable speech and chewing.

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3. The Eight Cranial Bones

Frontal Bone

• Forms the forehead and upper eye sockets.

• Houses the frontal sinus and contributes to the anterior cranial fossa.

Parietal Bones (x2)

• Large flat bones on either side of the skull.

• Connected by the sagittal suture.

Temporal Bones (x2)

• Includes the mastoid, petrous, squamous, and tympanic parts.

• Mastoid portion has air cells linked to the middle ear.

Occipital Bone

• Houses the foramen magnum for the spinal cord.

• Articulates with the atlas vertebra.

Sphenoid Bone

• Butterfly-shaped. Central in the skull base.

• Contains the sella turcica, where the pituitary gland sits.

Ethmoid Bone

• Separates nasal cavity from the brain.

• Includes the cribriform plate, crucial for smell via olfactory foramina.

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4. Facial Bones of the Skull

The viscerocranium includes 14 bones:

• Maxillae (2)

• Zygomatic bones (2)

• Nasal bones (2)

• Lacrimal bones (2)

• Inferior nasal conchae (2)

• Palatine bones (2)

• Vomer (1)

• Mandible (1)

They form the face, nasal cavity, oral cavity, and the orbits for the eyes. The mandible is the only moveable bone of the skull.

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5. Major Cranial Sutures and Fontanelles

Sutures are fibrous joints connecting skull bones. Major ones include:

• Coronal – between frontal and parietals

• Sagittal – between parietals

• Lambdoid – between parietals and occipital

• Squamous – between temporal and parietal

In newborns, fontanelles (soft spots) allow the skull to compress during birth and expand with brain growth.

Developmental Insight:

Understanding cranial sutures in adults vs. newborns helps in diagnosing conditions like craniosynostosis, where sutures close prematurely.

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6. Skull Base & Cranial Fossae

The skull base is divided into three fossae, each housing specific brain regions:

Anterior Cranial Fossa

• Holds the frontal lobes

• Includes the cribriform plate for olfactory nerves

Middle Cranial Fossa

• Holds the temporal lobes and pituitary

• Contains sella turcica, foramina rotundum, ovale, spinosum

Posterior Cranial Fossa

• Deepest part; houses cerebellum and brainstem

• Key exit: foramen magnum

📌 Bonus Tip: Use skull base diagrams to visualize foramina and understand nerve pathways—a top study hack for med students.

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7. Important Foramina and Nerve Pathways

Foramina (openings) allow nerves and blood vessels to pass through the skull. Here’s a simplified table:

Use this Wikipedia article on skull foramina for further reading.

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8. Clinical Relevance: Pterion, Fractures, and Surgeries

The Pterion

The pterion is where the frontal, parietal, temporal, and sphenoid bones meet. A blow here can rupture the middle meningeal artery, causing a life-threatening epidural hematoma.

Skull Fractures

• Basilar skull fracture → CSF leaks, “raccoon eyes”

• Depressed fractures → brain injury risk

• Frontal sinus fractures → cosmetic and infection concerns

Transsphenoidal Surgery

This technique accesses the pituitary gland via the sphenoid sinus. It’s commonly used to remove tumors. Understanding the sella turcica and surrounding bones is vital for surgical success.

🔗 Learn more about clinical anatomy in resources like Forbes Health’s brain and skull conditions for patient-friendly overviews.

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9. Visual Aids and Study Resources

Visual learners benefit from labeled diagrams, 3D models, and quizzes. Here’s what we recommend:

• BioDigital Human – interactive skull models

• Visible Body – muscle, bone, nerve overlays

• Wikimedia Commons – free, high-resolution anatomical drawings

• Quizlet – flashcard sets on skull foramina and cranial nerves

💡 Create a downloadable “Skull Foramina Chart with Cranial Nerves” PDF to attract backlinks and help readers study offline.

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10. Final Thoughts + More Reading

The cranium is more than a protective helmet. It’s a complex, interconnected system of bones, passages, and functional structures vital to human life. From cranial nerves passing through foramina to pediatric implications of early suture closure, skull anatomy is critical for both academic and clinical understanding.

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🧭 Additional Resources:

• Internal:
  👉 What Is Another Name for the Cranium? — MicroMinds

• External:
  📚 Wikipedia: Skull Anatomy Overview
  📘 Forbes Health: Neurological Health

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FAQ Section (For FAQ Schema)

Q: How many bones are in the skull?

A: 22 bones: 8 cranial and 14 facial.

Q: What passes through the superior orbital fissure?

A: Cranial nerves III, IV, V1, VI, and ophthalmic vein.

Q: What is the function of the cribriform plate?

A: It allows passage of the olfactory nerves from the nasal cavity to the brain.