Correct spelling for the English word "medullisplnal" is [mˈɛdəlˌɪsplnə͡l], [mˈɛdəlˌɪsplnəl], [m_ˈɛ_d_ə_l_ˌɪ_s_p_l_n_əl] (IPA phonetic alphabet).
Relating to the spinal cord.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.