ðə sɚɹˌiːbɹəspˈaɪnəl fˈaɪbɚz, dᵻɹˈaɪvd fɹʌmðə sˈɛlz ʌvðə mˈoʊɾɚɹ ˈɛɹiə ʌvðə sɚɹˈiːbɹəl kˈɔːɹɾɛks, ˈɑːkjʊpˌaɪ ðə mˈɪdəl θɹˈiːfˈɪfθs ʌvðə bˈeɪs; ðeɪ ɑːɹ kəntˈɪnjuːd pˈɑːɹtli tə ðə nˈuːklɪi ʌvðə mˈoʊɾɚ kɹˈeɪnɪəl nˈɜːvz, bˌʌt mˈeɪnli ˌɪntʊ ðə pˈɪɹɐmˌɪdz ʌvðə mˈɛdʌlə ˌɑːblɔŋɡˈɑːɾə.
The cerebrospinal fibers, derived from the cells of the motor area of the cerebral cortex, occupy the middle three-fifths of the base; they are continued partly to the nuclei of the motor cranial nerves, but mainly into the pyramids of the medulla oblongata.