Osteology related to neuroanatomy

Question 1

What does the skull consist of?

Answer 1

Neurocranium and Viscerocranium

Question 2

What are the eight bones that form the neurocranium and what does it divide into?

Answer 2

Frontal, parietal (paired), occipital, sphenoid, temporal (paired), and ethmoid.

Skullcap (Calveria) and Cranial base

Question 3

Which fourteen bones constitute the viscerocranium?

Answer 3

Maxilla (paired), mandible, zygomatic (paired), nasal (paired), lacrimal (paired), palatine (paired), vomer, and inferior nasal concha (paired).

Question 4

What are the primary sutures of the skull?

Answer 4

Coronal, sagittal, lambdoid, and squamosal sutures

Question 5

Where is the coronal suture located, and what bones does it connect?

Answer 5

The coronal suture is located at the front of the skull, connecting the frontal bone to the parietal bones.

Question 6

Where is the sagittal suture located, and what bones does it connect?

Answer 6

The sagittal suture is located along the midline of the skull, connecting the two parietal bones.

Question 7

Where is the lambdoid suture located, and what bones does it connect?

Answer 7

The lambdoid suture is located at the back of the skull, connecting the parietal bones to the occipital bone.

Question 8

Where is the squamosal suture located, and what bones does it connect?

Answer 8

The squamosal suture is located on the sides of the skull, connecting the temporal bones to the parietal bones. “Squishy Headphones”

Question 9

What is the bregma, and where is it located?

Answer 9

The bregma is the junction point of the coronal and sagittal sutures, located at the top of the skull.

Question 10

What is the lambda, and where is it located?

Answer 10

The lambda is the junction point of the lambdoid and sagittal sutures, located at the back of the skull.

Question 11

What is the pterion, and which bones meet at this point?

Answer 11

The pterion is the region where the frontal, parietal, temporal, and sphenoid bones meet on the side of the skull.

Question 12

What is the asterion, and which bones meet at this point?

Answer 12

The asterion is the point where the parietal, occipital, and temporal bones meet on the side of the skull.

Question 13

What are the primary sutures of the skull, and what bones do they connect?

Answer 13

The primary sutures are:

Coronal Suture: Connects the frontal bone to the parietal bones.

Sagittal Suture: Connects the two parietal bones along the midline.

Lambdoid Suture: Connects the parietal bones to the occipital bone.

Squamosal Suture: Connects the temporal bones to the parietal bones.

Question 14

What are fontanelles, and why are they important?

Answer 14

Fontanelles are soft, membranous gaps between the cranial bones in infants. They allow for the skull to mold during childbirth and accommodate rapid brain growth during early development.

Question 15

Where is the anterior fontanelle located, and when does it typically close?

Answer 15

The anterior fontanelle is located at the junction of the coronal and sagittal sutures. It typically closes between 18 months and 2 years of age.

Question 16

Where is the posterior fontanelle located, and when does it typically close?

Answer 16

The posterior fontanelle is located at the junction of the lambdoid and sagittal sutures. It typically closes by 2 to 3 months of age.

Question 17

Where is the sphenoidal fontanelle located, and when does it typically close?

Answer 17

The sphenoidal fontanelle is located at the junction of the frontal, parietal, temporal, and sphenoid bones. It typically closes by 6 months of age.

Question 18

Where is the mastoid fontanelle located, and when does it typically close?

Answer 18

The mastoid fontanelle is located at the junction of the parietal, occipital, and temporal bones. It typically closes between 6 to 18 months of age.

Question 19

What are the three divisions of the cranial cavity?

Answer 19

Anterior Cranial Fossa
Middle Cranial Fossa
Posterior Cranial Fossa

Question 20

Which bones form the anterior cranial fossa, and what structures does it contain?

Answer 20

The anterior cranial fossa is formed by the frontal bone, ethmoid bone, and the lesser wings of the sphenoid bone. It contains the frontal lobes of the brain and the olfactory bulbs.

Question 21

Which bones form the middle cranial fossa, and what structures does it contain?

Answer 21

The middle cranial fossa is formed by the greater wings of the sphenoid bone, the temporal bones, and the parietal bones. It houses the temporal lobes of the brain and the pituitary gland.

Question 22

Which bones form the posterior cranial fossa, and what structures does it contain?

Answer 22

The posterior cranial fossa is formed by the occipital bone, temporal bones, and the posterior part of the parietal bones. It contains the cerebellum, pons, and medulla oblongata.

Question 23

What are foramina, and what is their function in the skull?

Answer 23

Foramina are openings in the bones of the skull that allow the passage of structures such as nerves and blood vessels.

Question 24

Which foramina are located in the anterior cranial fossa, and what structures pass through them?

Answer 24

In the anterior cranial fossa, the cribriform plate of the ethmoid bone contains multiple small foramina through which the olfactory nerve (CN I) fibers pass.

Question 25

Which foramina are located in the middle cranial fossa, and what structures pass through them?

Answer 25

Optic Canal: Optic nerve (CN II) and ophthalmic artery. Superior Orbital Fissure: Oculomotor nerve (CN III), trochlear nerve (CN IV), ophthalmic branch of the trigeminal nerve (CN V₁), abducent nerve (CN VI), and ophthalmic veins. Foramen Rotundum: Maxillary branch of the trigeminal nerve (CN V₂). Foramen Ovale: Mandibular branch of the trigeminal nerve (CN V₃), accessory meningeal artery, and lesser petrosal nerve. Foramen Spinosum: Middle meningeal artery and vein, and meningeal branch of the mandibular nerve (CN V₃).

Question 26

Which foramina are located in the posterior cranial fossa, and what structures pass through them?

Answer 26

Internal Acoustic Meatus: Facial nerve (CN VII), vestibulocochlear nerve (CN VIII), and labyrinthine artery. Jugular Foramen: Glossopharyngeal nerve (CN IX), vagus nerve (CN X), accessory nerve (CN XI), internal jugular vein, and inferior petrosal sinus. Hypoglossal Canal: Hypoglossal nerve (CN XII). Foramen Magnum: Medulla oblongata, meninges, vertebral arteries, spinal accessory nerve (CN XI), and anterior and posterior spinal arteries.

Question 27

What structures pass through the foramen rotundum?

Answer 27

The foramen rotundum transmits the maxillary nerve (V₂), a branch of the trigeminal nerve.

Question 28

What structures pass through the foramen ovale?

Answer 28

The foramen ovale allows passage of the mandibular nerve (V₃), a branch of the trigeminal nerve, the accessory meningeal artery, and occasionally the lesser petrosal nerve.

Question 29

What structures pass through the foramen spinosum?

Answer 29

The foramen spinosum transmits the middle meningeal artery, the meningeal branch of the mandibular nerve (V₃), and the meningeal vein.

Question 30

What structures pass through the internal acoustic meatus?

Answer 30

The internal acoustic meatus transmits the facial nerve (VII), the vestibulocochlear nerve (VIII), and the labyrinthine artery.

Question 31

What structures pass through the jugular foramen?

Answer 31

The jugular foramen allows passage of the glossopharyngeal nerve (IX), the vagus nerve (X), the accessory nerve (XI), the internal jugular vein, and the inferior petrosal sinus.

Question 32

What structures pass through the hypoglossal canal?

Answer 32

The hypoglossal canal transmits the hypoglossal nerve (XII).

Question 33

What structures pass through the foramen magnum?

Answer 33

The foramen magnum allows passage of the medulla oblongata, the meninges, the vertebral arteries, the spinal accessory nerve (XI), and the anterior and posterior spinal arteries.

Question 34

What structures pass through the foramen magnum?

Answer 34

The foramen magnum allows passage of the medulla oblongata, which becomes the spinal cord, the meninges, the vertebral arteries, and the spinal accessory nerve (CN XI).

Question 35

What structures pass through the carotid canal?

Answer 35

The carotid canal transmits the internal carotid artery (ICA) and the internal carotid nerve plexus.

Question 36

What structures pass through the stylomastoid foramen?

Answer 36

The stylomastoid foramen allows passage of the facial nerve (CN VII) and the stylomastoid artery.

Question 37

What structures are located in the anterior cranial fossa?

Answer 37

The anterior cranial fossa houses the frontal lobes of the cerebrum.

Question 38

What structures are located in the middle cranial fossa?

Answer 38

The middle cranial fossa contains the temporal lobes of the cerebrum.

Question 39

What structures are located in the posterior cranial fossa?

Answer 39

The posterior cranial fossa lodges the cerebellum and parts of the brainstem.

Question 40

What midline structures are found in the cranial cavity?

Answer 40

Midline structures include the hypophyseal (pituitary) fossa, the brainstem, and the foramen magnum, which allows the medulla oblongata to become the spinal cord.