ðə pˈɛktᵻnˌeɪt mˈʌsəlz mˈʌskjʊlˌaɪ pˌɛktɪnˈɑːɾi ɑːɹ pˈæɹəlˌɛl mˈʌskjʊlɚ ɹˈɪdʒᵻz ɪnðə wˈɔːlz ʌvðɪ ˈeɪtɹiə ʌvðə hˈɑːɹt.
The pectinate muscles (musculi pectinati) are parallel muscular ridges in the walls of the atria of the heart.