Glossary of plant morphology others may form a tight spiral, or whorl, around the flower stem. First, at the base, are those non-reproductive structures involved in protecting the flower when it is still a bud, the sepals, then are those parts that play a role in attracting pollinators and are typically coloured, the petals, which together with the sepals make up the perianth (perigon, perigonium). If the perianth is differentiated, the outer whorl of sepals forms the calyx, and the inner whorl of petals, the corolla. If the perianth is not differentiated into sepals and petals, they are collectively known as tepals. In some
Calyx of Held of Held has been used to understand a variety of mechanisms related to development of, and vesicle release of the synapse. The calyx of Held is a part of the auditory system, connecting the globular bushy cells (GBCs) of the anteroventral cochlear nucleus to the principal neurons of the medial nucleus of the trapezoid body (MNTB). As a synapse, the function of the calyx of Held is to transmit the signal from the GBCs to the principal neurons. The principal neurons of the MNTB are glycinergic, thus hyperpolarizing the superior olivary complex (SOC) nuclei in nearby cells and producing tonotopic