GEN ANA Reviewer for (1) quiz

• The HEAD is formed mainly by the skull with the brain and its covering meninges enclosed in the cranial cavity.
• The posterior aspect of the occipital bone is bounded by the internal surface of the squamous part of the occipital bone.
• The skull's role is to protect the brain.
• The skull is made up of 8 cranial bones and 14 facial bones.
• The regions of the head include the frontal, parietal, occipital, temporal, auricular, orbital, nasal, infraorbital, zygomatic, buccal, oral, and mental regions.
• The bones of the skull can be divided into those of the cranium and those of the face.
• The vault is the upper part of the cranium, and the base of the skull is the lowest part of the cranium.
• The cranium consists of the following bones, two of which are paired: Frontal bone, Parietal bones, Occipital bone, Temporal bones, Sphenoid bone, and Ethmoid bone.
• The facial bones consist of the following, two of which are single: Zygomatic bones and Maxillae.
• The cranial cavity contains the brain and its surrounding meninges, portions of the cranial nerves, arteries, veins, and venous sinuses.
• The internal surface of the vault shows the coronal, sagittal, and lambdoid sutures.
• The interior of the base of the skull is divided into three cranial fossae: anterior, middle, and posterior.
• Routine radiologic examination of the head and neck concentrates mainly on the bony structures because the brain, muscles, tendons, and nerves blend into a homogeneous mass.
• The cranial bones and their parts formed of bone substance that is more compact than other bone substance (e.g., the petrous part of the temporal bone) produce shadows on the radiograph of greater density.
• Bones and their parts, which are made up of substance that is less compact (e.g., diploe), produce shadows of lesser density.
• Air cavities are seen as unshadowed areas.
• The technique of cerebral arteriography can be used to detect abnormalities of the cerebral arteries and localization of space-occupying lesions such as tumors, blood clots, or abscesses.
• CT is commonly used for the detection of intracranial lesions.
• MRI is also commonly used for detection of intracranial lesions.
• The middle cranial fossa is separated from the posterior cranial fossa by the petrous part of the temporal bone.
• The dura mater is sometimes referred to as the pachymeninx.
• MRI is absolutely safe to the patient, and because it provides better differentiation between gray and white matter in the brain, its use can be more revealing than a CT scan.
• The CSF has three basic functions: Mechanical Protection, Homeostatic function, and Circulation.
• The most important artery from a clinical standpoint is the middle meningeal artery, which is commonly damaged in head injuries.
• The middle cranial fossa consists of a small median part (formed by the body of the sphenoid) and expanded lateral parts (form concavities on either side, which lodge the temporal lobes of the cerebral hemispheres).
• The meningeal veins lie in the endosteal layer of dura.
• The veins lie lateral to the arteries.
• The anterior cranial fossa is separated from the middle cranial fossa by the lesser wing of the sphenoid.
• The posterior cranial fossa is deep and lodges the parts of the hindbrain, namely, the cerebellum, pons, and medulla oblongata, with boundaries: Anteriorly is bounded by the superior border of the petrous part of the temporal bone.
• The cranial cavity contains the brain with its vessels and membranes, the cranial nerves, vessels on the outermost membrane, the meninges, and the dura mater.
• Branches of the trigeminal, vagus, and first three cervical nerves and branches from the sympathetic system pass to the dura.
• The middle meningeal vein follows the branches of the middle meningeal artery.
• The dura mater has two layers: the endosteal layer and the meningeal layer.
• The arachnoid and pia mater together constitute the leptomeninges.
• The pia mater is the final and innermost layer, a 'mesh-like, vascular membrane which derives its blood supply from the internal carotid and vertebral arteries.
• The anterior cranial fossa lodges the frontal lobes of the cerebral hemispheres, with boundaries: Anteriorly by the inner surface of the frontal bone, midline is a crest for the attachment of the falx cerebri, and posterior boundary is the sharp lesser wing of the sphenoid.
• The arachnoid is the middle layer and is a thin and fragile layer that surrounds the brain.