Neuroscience

Gross Anatomy of the Brain Neuroscience is a composite of several disciplines including neuroanatomy, neurophysiology, neurology, neuropathology, neuropharmacology, behavioral sciences, and cell biology. An overview of the structural organization of the nervous system is helpful when beginning to study the neurosciences. However, first it would be useful to define some basic terms that will be […]

Overview of the Central Nervous System (Gross Anatomy of the Brain) Part 2

Parietal Lobe The parietal lobe houses the functions that perceive and process somatosensory events. It extends posteriorly from the central sulcus to its border with the occipital lobe (Fig. 1-2). The parietal lobe contains the postcentral gyri, which has the central sulcus as its anterior border and the postcentral sulcus as its posterior border. The […]

Overview of the Central Nervous System (Gross Anatomy of the Brain) Part 3

Basal Ganglia The basal ganglia play an important role in motor integration processes associated with the cerebral cortex. Damage to this region results in motor dysfunctions referred to as dyskinesias (i.e., disorders of movement at rest). The most prominent structures of the basal ganglia are the caudate nucleus, putamen, and globus pallidus (Figs. 1-6 and […]

Overview of the Central Nervous System (Gross Anatomy of the Brain) Part 4

Clinical Case The following clinical case is intended to illustrate some of the basic neuroanatomical concepts presented in this topic. You are not expected to diagnose the patient’s condition or suggest any therapy or medical steps to be taken. Rather, we hope that this case and those that follow will demonstrate the very real clinical […]

Development of the Nervous System (Gross Anatomy of the Brain) Part 1

Early Aspects of Development The nervous system develops from ectoderm, the surface layer of embryonic tissue. By the third to fourth week of embryonic development, the notochord, of mesodermal origin, induces the development of the neural plate (Fig. 2-1A). By the third to fourth week of embryonic development, there is a high rate of cell […]

Development of the Nervous System (Gross Anatomy of the Brain) Part 2

The Brain Myelencephalon (Medulla) Recall that the alar and basal plates of the mantle layer, which are separated by a shallow groove, the sulcus limi-tans, form the walls of the neural canal of the developing nervous system. Although the size of the neural canal remains relatively small in the developing spinal cord, this is not […]

Development of the Nervous System (Gross Anatomy of the Brain) Part 3

Abnormalities in Development of the Nervous System Spina Bifida Spina bifida, called myeloschisis, occurs when the posterior neuropore fails to close. It is manifested by a failure of the vertebral canal to close, and spina bifida follows. Two types of spina bifida have been described: spina bifida occulta and spina bifida aperta (also called spina […]

Meninges and Cerebrospinal Fluid (Gross Anatomy of the Brain) Part 1

The Meninges The tissues comprising the brain and spinal cord are very delicate and require special protection. This is provided by the bony cranial vault, the bony vertebral canal, and the meninges. The cranial cavity is generally divided into three regions known as the anterior, middle, and posterior fossae, which house the anterior frontal lobe, […]

Meninges and Cerebrospinal Fluid (Gross Anatomy of the Brain) Part 2

Cerebrospinal Fluid Formation About 70% of the CSF present in the brain and spinal cord is produced by the choroid plexuses. The remaining 30% of CSF, which is secreted by the parenchyma of the brain, crosses the ependyma (a single layer of ciliated columnar epithelial cells lining the ventricular system) and enters the ventricles. The […]

Blood Supply of the Central Nervous System (Gross Anatomy of the Brain) Part 1

The central nervous system (CNS) represents one of the most metabolically active systems in the body. The metabolic demands of the brain must be met with the blood supply to this organ. Normal cerebral blood flow is about 50 mL/100 g of brain tissue/min. Thus, a brain of average weight (1,400-1,500 g) has a normal […]