Solitary tract

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Cross-section through the medulla oblongata at the level of the olive -
15 (blue): Tractus solitarius

The solitary tract ( Latin tract , train ', solitary , alone') also fasciculus solitarius or fasciculus rotundus rare Solitariustrakt called, is a pathway in the central nervous system (CNS).

The solitary tract runs through the dorsal medulla oblongata on both sides as a delimitable bundle of strongly myelinated nerve fibers within the core area known as the nucleus tractus solitarii . It extends approximately from the level of the facial nucleus in the caudal pons to the pyramidal junction at the transition from the medullary brain to the cervical segments of the spinal cord .

The pathway mainly carries primary afferent axons of the cranial nerves VII facial nerve , IX glossopharyngeal nerve and X vagus nerve . In a descending direction, these are distributed to subdivisions of the core complex named after the pathway , where they end somatotopically and functionally categorized in different sub-nuclei. The fibers from the tract that cross the midline caudally in the area of ​​the commissural nucleus are often ascending bilateral projections .

The primarily viscerosensory fibers of the tracus solitarius convey signals from chemoreceptors as well as stretch and pressure receptors from the head, chest and abdominal viscera. As the afferent thigh, they are involved in various respiratory , cardiovascular and intestinal reflexes.

The primary afferents of the sense of taste , called taste fibers, run as special viscerosensory fibers in the rostral part .

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Individual evidence

  1. Benninghoff: Macroscopic and microscopic anatomy of humans, Vol. 3. Nervous system, skin and sensory organs . Urban and Schwarzenberg, Munich 1985, ISBN 3-541-00264-6 , p. 276.