Stellaria umbellata inflorescence is an umbel-shaped array of several flowers each on an arching or erect pedicels. The flower has five pointed green sepals each no more than 3 millimeters long. There are occasionally tiny white petals within the calyx of sepals, but these are generally absent. Stellaria umbellata Stellaria umbellata is a species of flowering plant in the pink family known by the common names umbrella starwort and umbellate starwort. It is native to western North America from Alaska and northwestern Canada to the southwestern United States, as well as parts of Asia, including Siberia. It grows in subalpine and alpine
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