Key Terms

Cognitive abulla

Loss of willpower because. an individual cannot carry a thought long enough.

back to top

Magnetic resonance imaging (MRI)

A noninvasive diagnostic technique that produces computerized images of internal body tissues and is based on nuclear magnetic resonance of atoms within the body induced by the application of radio waves.

back to top

Positron emission tomography (PET)

Is an imaging test that uses a radioactive substance (called a tracer) to look for disease in the body.

back to top

Single photon emission computed tomography

A medical imaging technique that is used especially for mapping brain function and that is similar to positron-emission tomography in using the photons emitted by the agency of a radioactive tracer to create an image but that differs in being able to detect only a single photon for each nuclear disintegration and in generating a lower-quality image.

back to top

Midbrain

Middle division of the three primary divisions of the developing vertebrate brain or the corresponding part of the adult brain that includes a ventral part containing the cerebral peduncles and a dorsal tectum containing the corpora quadrigemina and that surrounds the aqueduct of Sylvius connecting the third and fourth ventricles.

back to top

Pons

A broad mass of chiefly transverse nerve fibers in the mammalian brain stem lying ventral to the cerebellum at the anterior end of the medulla oblongata.

back to top

Medulla oblangata

The somewhat pyramidal last part of the vertebrate brain developed from the posterior portion of the hindbrain and continuous posteriorly with the spinal cord, enclosing the fourth ventricle, and containing nuclei associated with most of the cranial nerves, major fiber tracts and decussations that link spinal with higher centers, and various centers mediating the control of involuntary vital functions (as respiration).

back to top

Spinal Cord

The thick longitudinal cord of nervous tissue that in vertebrates extends along the back dorsal to the bodies of the vertebrae and is enclosed in the vertebral canal formed by their neural arches, is continuous anteriorly with the medulla oblongata, gives off at intervals pairs of spinal nerves to the various parts of the trunk and limbs, serves not only as a pathway for nervous impulses to and from the brain but as a center for carrying out and coordinating many reflex actions independently of the brain, and is composed largely of white matter arranged in columns and tracts of longitudinal fibers about a large central core of gray matter somewhat H-shaped in cross section and pierced centrally by a small longitudinal canal continuous with the ventricles of the brain.

back to top

Forebrain

The anterior of the three primary divisions of the developing vertebrate brain or the corresponding part of the adult brain that includes especially the cerebral hemispheres, the thalamus, and the hypothalamus and that especially in higher vertebrates is the main control center for sensory and associative information processing, visceral functions, and voluntary motor functions.

back to top

Cerebro-spinal meningitis

Inflammation of the meninges of both brain and spinal cord; specifically : an infectious often epidemic and fatal meningitis caused by the meningococcus.

back to top