Anatomy and Pathology of Brain and Skull

Basic Sectional and Radiographic Anatomy

• Skull comprises 8 cranial bones and 14 facial bones.
• Cranial bones are divided into calvaria (frontal, parietal, occipital) and base (temporal, sphenoid, ethmoid).
• Main skull sutures include coronal, sagittal, lambdoid, and squamosal; the metopic suture is sometimes present in adults.
• Cranial vault contains all intracranial structures; everything outside is classified as extracranial.
• Cranial fossae: anterior (frontal lobes), middle (temporal lobes), posterior (cerebellum and brain stem), and pituitary fossa (pituitary gland).

Sinuses

• Sinuses vary greatly among individuals, housing air and important for potential injuries.
• Maxillary sinuses are relevant for orbital injuries; sphenoid and ethmoid sinuses are involved in basal skull fractures.
• Mastoid air cells connect to the middle ear, while frontal sinuses can be absent in some individuals.

Meninges

• Meninges consist of three layers: dura mater, arachnoid membrane, and pia mater.
• Provide structural support for vasculature and protect the CNS with CSF from mechanical damage.
• Meningitis and intracranial bleeds often affect the meninges.

Dura Mater

• Thick and tough outermost layer of meninges, located beneath skull and vertebral bones.
• Contains dural venous sinuses responsible for venous drainage into internal jugular veins.
• Dural reflections include:
  • Falx cerebri: separates the cerebral hemispheres.
  • Tentorium cerebelli: separates occipital lobes from cerebellum with a midbrain passage.
  • Falx cerebelli: separates cerebellar hemispheres.
  • Diaphragma sellae: covers sphenoid's hypophysial fossa, allowing passage for the pituitary stalk.

Traumatic Brain Injury

• Intracranial hemorrhages include:
  • Extra-axial: extradural, subdural, subarachnoid.
  • Intra-axial hemorrhage results directly within brain tissues.
• Complications: mass effect, cerebral edema, herniation, and potential skull fractures.

Non-Traumatic Emergency Conditions

• Hydrocephalus: condition of excess cerebrospinal fluid.
• Infections such as meningitis, encephalitis, abscesses, and empyema pose serious risks.
• Acute ischemic stroke and hypoxic ischemic encephalopathy are critical conditions requiring immediate intervention.

This quiz explores the sectional anatomy and pathology related to the brain and skull, covering topics such as image orientation, skull structures, and traumatic brain injuries. Participants will test their knowledge on key concepts, including cerebrospinal fluid spaces and types of intracranial hemorrhage.