Term
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Definition
| The calvaria is the upper domelike portion of the bony skull (the skullcap). |
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Term
| Where is the coronal suture? |
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Definition
| The coronal suture lies in the coronal plane between the unpaired frontal bone and the two parietal bones. |
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Term
| Where is the sagittal suture? |
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Definition
| The sagittal suture is on the top of the skull between the two parietal bones. |
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Term
| Where is the pterion? Why is it a clinically important landmark? |
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Definition
| The pterion is an “H”-shaped sutural junction located on the lateral aspect of the skull. It can be found at the junction of the greater wing of the sphenoid, the squamous temporal, the frontal, and the parietal bones. It is clinically important because it lies over the course of a large middle meningeal artery branch. Fractures across the pterion can lead to epidural hematomas. |
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Term
| Where would one find the middle meningeal artery? From what artery does it arise? |
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Definition
| The middle meningeal artery arises from the maxillary artery and enters the cranial cavity through the foramen spinosum. Its branches travel between the inside of the skull bones and the dura mater. |
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Term
| What type of hematoma typically results from tearing the middle meningeal artery? |
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Definition
Epidural hematomas (see answer #4 below).
The middle meningeal artery arises from the maxillary artery and enters the cranial cavity through the foramen spinosum. Its branches travel between the inside of the skull bones and the dura mater. |
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Term
| What cranial fossa contains the foramen magnum? |
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Definition
| The foramen magnum is in the posterior cranial fossa. |
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Term
| What cranial fossa contains the superior orbital fissure? |
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Definition
| The superior orbital fissure is in the middle cranial fossa. |
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Term
| What is the sella turcica? What important glandular structure is associated with it? |
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Definition
| The sella turcica is a saddle-like prominence on the upper surface of the sphenoid bone, situated in the middle cranial fossa and dividing it into two halves. It contains the pituitary gland. |
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Term
| What is a gyrus? What is a sulcus? |
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Definition
| A gyrus is one of the prominent rounded elevations that form the cerebral hemispheres. The gyri are separated by sulci, which are the grooves or furrows on the surface of the cerebrum. |
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Term
| Where is the pons located? |
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Definition
| The pons is located on the ventral surface of the brainstem between the midbrain and the medulla oblongata, inferior to the cerebellum. |
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Term
| Where is the medulla oblongata located? |
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Definition
| The medulla oblongata is that portion of the brainstem between the pons and the spinal cord. It is continuous with the spinal cord at the foramen magnum. |
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Term
| What is the falx cerebri? |
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Definition
| The falx cerebri is the sickle-shaped fold of dura mater in the longitudinal fissure between the two cerebral hemispheres. |
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Term
| What would one find within the superior sagittal sinus? |
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Definition
| The superior sagittal sinus contains venous blood. It also contains the arachnoid granulations, which protrude into the sinus from beneath as the CSF pressure rises. |
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Term
| What is the predominant route by which cerebral blood drains from the cranial cavity? |
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Definition
| The venous blood within the cranial cavity eventually collects in the larger cerebral veins which drain into one of several dural venous sinuses. The blood in the dural venous sinuses drains predominantly into the internal jugular vein. |
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Term
| What are emissary veins? Why are they clinically important structures? |
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Definition
| Emissary veins are venous channels located between the venous sinuses of the dura mater and the veins of the diploë and the scalp. They are clinically important in that they provide a potential passage for the spread of infection between the scalp and the intracranial venous sinuses. |
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Term
| Where is cerebrospinal fluid (CSF) produced? |
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Definition
| CSF is produced within the ventricles of the brain by the choroid plexus. |
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Term
| What is the name of the structure that produces CSF? |
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Definition
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Term
| How does the CSF eventually drain into the venous system? |
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Definition
| The main passageway of CSF drainage is through the arachnoid granulations and into the venous blood of the superior sagittal sinus. |
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Term
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Definition
| Hydrocephalus is any condition marked by an excessive accumulation of CSF within the cranial cavity. One common type of hydrocephalus, caused by a congenital blockage of the cerebral aqueduct, results in dilation of the cerebral ventricles, thinning of the brain tissues and separation of cranial bones. |
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Term
| Which two pairs of major arteries enter the cranial cavity to supply blood to the brain? |
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Definition
| The internal carotid arteries and the vertebral arteries. |
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Term
| What is the major unpaired artery that is formed from the two vertebral arteries within the cranial cavity? |
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Definition
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Term
| How do the anterior, middle, and posterior cerebral arteries arise? |
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Definition
| The internal carotid arteries terminate within the cranial cavity by dividing into the anterior and middle cerebral arteries. The single basilar artery ends by dividing into two posterior cerebral arteries. |
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Term
| What is the Circle of Willis? |
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Definition
| The Circle of Willis is an anastomotic “circle” of arteries (roughly pentagonal in outline) at the base of the brain, formed, sequentially (in anterior to posterior direction) by the anterior communicating artery, the two anterior cerebral, the two internal carotid, the two posterior communicating, and the two posterior cerebral arteries. |
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Term
| How many pairs of cranial nerves are there? |
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Definition
| There are 12 pairs of cranial nerves. |
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Term
| What is the name of the seventh cranial nerve? |
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Definition
| The seventh cranial nerve (CN VII) is the facial nerve. |
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Term
| What is the name of the tenth cranial nerve? |
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Definition
| The tenth cranial nerve (CN X) is the vagus nerve. |
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Term
| What is the cranial nerve number of the glossopharyngeal nerve? |
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Definition
| The glossopharyngeal nerve is CN IX. |
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Term
| Which cranial nerves travel through a foramen associated with the internal jugular vein? |
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Definition
| CNs IX, X, and XI travel through the jugular foramen. |
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Term
| Which cranial nerves travel through the cribriform plate openings? |
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Definition
| CN I travels through the cribriform plate. |
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Term
| Which cranial nerves travel through the superior orbital fissure? |
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Definition
| CNs III, IV, V1, and VI travel through the superior orbital fissure. |
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Term
| In which cranial fossa is the internal auditory meatus located? Which cranial nerves travel through it? |
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Definition
| The internal auditory meatus, for CNs VII and VIII, is in the posterior cranial fossa. |
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Term
| Which cranial nerve has a component that travels through the foramen magnum? |
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Definition
| CN XI (spinal accessory nerve) has a spinal root that travels through the foramen magnum. |
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Term
| How do postganglionic sympathetic nerves get into the cranial cavity? |
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Definition
| Sympathetic nerves enter the cranial cavity in a plexus on the major arteries traveling from the neck into the cranial cavity – especially the internal carotid arteries. |
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Term
| What important glandular structure lies immediately inferior to the optic chiasm? |
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Definition
| The pituitary gland lies immediately below the optic chiasm. |
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Term
| Which unique cranial nerve structure lies within the Circle of Willis? |
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Definition
| The optic chiasm of CN II lies within the Circle of Willis. |
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Term
| Where is the cavernous sinus located? |
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Definition
| The cavernous sinuses are located on either side of the sella turcica in the middle cranial fossae. |
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Term
| Which artery travels directly through the cavernous sinus? |
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Definition
| The internal carotid arteries travel through the cavernous sinus. |
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