Sepal Sepal A sepal ( or ) is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom. The term "sepalum" was coined by Noël Martin Joseph de Necker in 1790, and derived from the Greek σκεπη ("skepi"), a covering. Collectively the sepals are called the calyx (plural calyces), the outermost whorl of parts that form a flower. The word "calyx" was adopted from the Latin "calyx", not to be confused with "calix", a cup or goblet. "Calyx" derived from
Calyx of Held the calyx is not only characteristic, but pragmatic in terms of auditory chronological development. As a synapse, the calyx of Held follows a mechanism similar to other synapses. A thorough description can be found under neurotransmission. Calcium influx for the immature calyx of Held is mediated by N-, P/Q-, and R-type calcium channels; however upon maturation only P/Q-type calcium channels become dominant. Upon calcium influx, the immature calyx of Held is highly reactive due to its small calcium buffer ability – this causes the release of glutamate even at low levels of calcium influx. Within the terminal, as with other