There are twelve pairs of cranial nerves in animals- The first pair or olfactory nerve joins the convex ventral face of the olfactory bulbs. The second pair or optic nerve arises from the lateral geniculate bodies; the optic tracts converge to the optic chiasma and are then continued as optic nerves. The third pair or […]
Ascending tract Ventral spino -thalamic tract: This ascending tract consists of fibres derived from the sensory neurons of dorsal gray column, which ascend directly upto two or three segments and then cross to the opposite side to reach the ventral white column. They pass up to the thalamus, from where they are relayed to the sensory
Ascending tracts Lateral spino thalamic tract: It lies medial to the preceding. The fibres arise from the dorsal horn of the opposite side cross the median plane and ascend through the medulla. It ascends as the spinal lemniscus and reaches the ventral portion of the lateral nucleus of the thalamus from where they are relayed
Fasciculus gracilis Comma tract Fasciculus cuneatus. The first two are ascending tracts conveying the same types of sensations. Fasciculus gracilis conveying impulses from the posterior parts of the body (posterior thoracic, lumbar, sacral and coccygeal) and the Fasciculus cuneatus conveying impulses from the anterior half (anterior cervical and thoracic). Both are in the dorsal white
Tract of spinal cord consist of bundles of medullated nerve fibers in the dorsal, lateral or ventral white columns or funiculi of the white mater of spinal cord. The fibers having similar origin, termination and function are grouped together and are called as tracts or fasciculi. Tract of spinal cord may be classified as- Sensory
The spinal cord is that part of the central nervous system situated in the vertebral canal. It extends from the foramen magnum to about the middle of the sacrum. It is approximately cylindrical and more or less compressed from above downward. It is continuous with the medulla oblongata at the foramen magnum, where there is
These Ventricles of Brain is present in the brain- Lateral ventricle, Third ventricle, and Fourth ventricle. LATERAL VENTRICLES They are right and left and each is an irregular cavity in the interior of each cerebral hemisphere communicating with each other and with the third ventricle by the foramen of Munro. Each ventricle has three parts,
Medulla Oblangata is the cranial continuation of the spinal cord and extends from the foramen magnum to the posterior margin of the pons. This is a quadrilateral structure wider in front than behind and compressed dorsoventrally. Its inferior surface is convex transversely and presents median fissure, which ends in front in a small depression called
The pons is located between the medulla oblongata and the cerebral peduncles. Pons is marked off from these ventrally by the anterior and the posterior transverse grooves. When viewed ventrally it is elongated, convex in both directions and presents a median groove, which lodges the basilar artery. Laterally a large part of it curves dorsally
The cerebellum or lesser brain is separated from the cerebral hemispheres by the great transverse fissure. It overlies the pons and greater part of the medulla oblongata and the fourth ventricle. It is globular in shape and compressed dorso-ventrally. The surface of the cerebellum is cut into gyri by narrow but deep sulci into which
