<prompt> Ventral tegmental decussation in cerebral peduncle is due to -Tectospinal tractTectobulbar tractVestibulospinal tractRubrospinal tract  <response>: Ans. is d i.e., Rubrospinal tract o Midbrain is divided into following parts1 Tectum: It is the part posterior to cerebral aqueduct. It is made up of two collicoli on each side right and left: Superior colliculus and inferior colliculus.2 Cerebral peduncle: It is the part anterior to cerebral aqueduct. Each cerebral peduncle is subdivided into a Crus cerebri anteriorly, b Substantia nigra in middle, and c Tegmentum posteriorly.o Cerebral puduncle has following pathways -A. At the level of inferior colliculusi Crus cerebri contains : a Middle two-third is occupied by corticospinal, and corticobulbar corticonuclearfibres ; b Medial one-sixth is traversed by frontopontine fibres; and c Lateral one-sixth contains temporopontine, parietopontine and occipitopontine fibres.ii Tegmentum contains : a Lemnisci: medial, trigeminal, spinal and lateral; b Decussation of superior cerebellar peduncles; c Tectospinal and rubrospinal tract, and d Medial longitudinal bundle.B. At the level of superior colliculusi Crus cerebri has same tracts as described above.ii Tegmentum has : a Lemnisci; b Dorsal tegmental decussation formed by decussation of tectospinal and tectobulbar tracts; c Ventral tegmental decussation formed by decussation of rubrospinal tract;d Medial longitudinal bundle, and e Emerging fibers of occulomotor nerve.iii Tectum shows posterior commisure connecting two superior colliculi. 