Structure of the Cerebrum

The cerebrum (ser'e-brum), which develops from the anterior portion of the forebrain, is the largest part of

Many ridges called convolutions, or gyri (sing., gyrus), separated by grooves, mark the cerebrum's surface. Generally, a shallow to somewhat deep groove is called a sulcus, and a very deep groove is called a fissure. The pattern of these elevations and depressions is complex, and it is distinct in all normal brains. For example, a longitudinal fissure separates the right and left cerebral hemispheres; a transverse fissure separates the cerebrum from the cerebellum; and sulci divide each hemisphere into lobes (figs. 11.15 and 11.16).

In a disorder called lissencephaly ("smooth brain"), a newborn has a smooth cerebral cortex, completely lacking the characteristic convolutions. Absence of a protein early in prenatal development prevents certain neurons from migrating within the brain, which blocks formation of convolutions. The child is profoundly mentally retarded, with frequent seizures and other neurological problems.

Corpus Callosum Vessels

Convolution Sulcus

Corpus callosum

Transverse fissure

Cerebellum

Spinal cord

Figure 11.15

The major portions of the brain include the cerebrum, the diencephalon, the cerebellum, and the brain stem (see also reference plate 76).

Skull

Meninges Cerebrum Diencephalon

Convolution Sulcus

Corpus callosum

Transverse fissure

Cerebellum

Spinal cord

Figure 11.15

The major portions of the brain include the cerebrum, the diencephalon, the cerebellum, and the brain stem (see also reference plate 76).

Structural Development of the Brain

Embryonic Vesicle

Spaces Produced

Regions of the Brain Produced

Forebrain

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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