Sacrum a lateral surface. The base of the sacrum, which is broad and expanded, is directed upward and forward. On either side of the base is a large projection known as an ala of sacrum and these alae (wings) articulate with the sacroiliac joints. The alae support the psoas major muscles and the lumbosacral trunk which connects the lumbar plexus with the sacral plexus. In the articulated pelvis the alae are continuous with the iliac fossa. Each ala is slightly concave from side to side, and convex from the back and gives attachment to a few of the fibers of the
O sacrum convivium "O sacrum convivium" exists in Gregorian and Ambrosian chant forms. Some of the many composers who have set the text are as follows: «O Sacrum Convivium» (2018) Obra premiada en el VI Concurso Internacional Amadeus de Composición Coral. O sacrum convivium O sacrum convivium is a Latin prose text honoring the Blessed Sacrament. It was included as an antiphon to Magnificat in the vespers of the liturgical office on the feast of Corpus Christi. The text of the office is attributed with some probability to Saint Thomas Aquinas. Its sentiments express the profound affinity of the Eucharistic celebration, described as