Corona radiata (CNS)

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Corona radiata is the term used in neuroanatomy to refer to the structure of white matter spread out like a corona of the fanned out fibers of various ascending and descending projection paths that connect the cerebral cortex ( cortex cerebri ) with other brain regions.

The corona radiata becomes visible after removing parts of the cerebral mantle

The corona radiata contains both afferents as corticopetal fibers to regions of the cerebral cortex and efferents emanating from there as corticofugal fibers. It lies essentially in the telencephalon , is in the region of basal ganglia close and going on here in the internal capsule on (internal capsule). The basal ganglia ( nuclei basales ) represent a type of bottleneck for the projection pathways on their way to or from the cerebral cortex .

The naming is based on their radial and fan-like expansion and the divergence, seen from the trunk ganglia . "Corona radiata" is therefore primarily a morphological term . The German name is "Stabkranz". A distinction is made between:

Representation of the corona radiata in transverse planes
(two half-sided horizontal sections)

Most of the fibers of the corona radiata emerge as an inner capsule through the basal core of the endbrain; On a horizontal section, they show a typically angular course, densely packed, the kink of which is called the knee. In the anterior thigh, projection trajectories descend from the frontal lobe ( tractus frontopontinus and frontothalamicus ). In the knee of the inner capsule there are descending fibers to the cranial nerve nuclei ( corticonuclear tract ), followed by the somatotopically structured fibers of the pyramidal tract for the spinal cord ( corticospinal fibers ) in the rear thigh . They are accompanied by ascending fibers ( fibrae thalamocorticales ) of sensitive tracts, especially to the post-central region in the parietal lobe . Later followed by descending fibers to pontine nuclei of the pons ( Fibrae temporopontinae and occipitopontinae ) and at the back of the optic radiation ( optic radiation ) from the lateral geniculate the visual cortex . The fibers of the auditory radiation ( Radiatio acustica ) run from the central knees past the inner capsule and sideways to the temporal lobe . All these fibers of projection tracks are summarized under the term corona radiata.

Representation of the corona radiata in frontal planes
(two half-sided coronal sections)

The ring of rods adjacent to the thalamus contains fiber bundles that connect between the thalamus and the cerebrum ( Fasciculi corticothalamici and thalamocorticales ), called Radiationes thalamicae . This also includes all somatic afferent projections that have been switched in the thalamic nuclei and run to the (somatosensory) cortex. Only the sensory fibers of the olfactory system reach the cortical regions of the cerebrum without switching in the core areas of the diencephalon .

The radiation thalami lies against the outer surface of the thalamus and thus continues in the inner part of the internal capsule. The thalamus is also used as a switch for descending orbits, as can already be seen from the aforementioned course of the frontothalamic tract. It also receives declining connections from areas of bark, to which its rising fibers project. A thalamocortical neuron circuit is thus closed. Because of the quality of consciousness mediated by the cerebral cortex, it can also be called a “ psychic reflex arc ”, through which certain perceptions are marked and proven with psychic qualities.

Individual evidence

  1. ↑ Johannes Sobotta and H. Becher: Atlas of the human anatomy. 3rd part: central nervous system a. a. Urban & Schwarzenberg, Munich 1962, Fig. 299, 300, pp. 331f.
  2. ^ Herrman Voss , Robert Herrlinger : Taschenbuch der Anatomie. Volume III: nervous system, sensory system, skin system, increment system. Fischer, Jena 1964, p. 62f.
  3. ↑ Peter Duus : Neurological-topical diagnostics. Anatomy, physiology, clinic. Thieme, Stuttgart 1990, ISBN 3-13-535805-4 , pp. 41, 43, 358, 360
  4. ↑ Helmut Ferner : Anatomy of the nervous system and the human sense organs. Reinhardt, Munich 1964, pp. 142ff.
  5. ↑ Alfred Benninghoff , Kurt Goerttler : Textbook of Human Anatomy. Shown with preference given to functional relationships. 3rd volume. Nervous system, skin and sensory organs. Urban and Schwarzenberg, Munich 1964, p. 224ff.

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