Streptanthus bracteatus Streptanthus bracteatus Streptanthus bracteatus is a species of flowering plant in the mustard family known by the common names bracted jewelflower and bracted twistflower. It is endemic to Texas in the United States. This annual or biennial herb has a branching stem up to 1.2 meters tall. It is hairless and generally waxy in texture. The basal leaves have lobed or toothed blades on long petioles, and the leaves higher on the stem have smooth or toothed edges. The inflorescence is a raceme of flowers and bracts. Each flower has a bell-shaped calyx of sepals and four purple petals which
Calyx of Held The first is that in the second week of development, myelination of the VCN axons in the MNTB increases. This prominent growth in myelin corresponds to the chronological development of the signaling circuit and adaptation of the calyx. The second ultrastructural change involves the principal neurons of the MNTBs, whose cell bodies and nuclei increase in surface area due to enlargement. This is a direct result of individual, larger postsynaptic densities breaking up into smaller, multiple densities. Potassium channels are vital in conducting the presynaptic action potential. The calyx contains several types of potassium channels, each differing in location and