Otic vesicle constricts to form the canalis reuniens. The central part of the otic vesicle represents the membranous vestibule, and is subdivided by a constriction into a smaller ventral part, the saccule, and a larger dorsal and posterior part, the utricle. The dorsal component of the inner ear also consists of what will become the semicircular canals. The utricle and saccule communicate with each other by means of a Y-shaped canal. The FGF, Bmp, Wnt and Pax genes are likely to be involved in otic induction. FGF and BMP signals help control patterning in the early otic vesicle. Fgf3 and Fgf10 are
History of anatomy own direct observation. His surviving 750 drawings represent groundbreaking studies in anatomy. Leonardo dissected around thirty human specimens until he was forced to stop under order of Pope Leo X. As an artist-anatomist, Leonardo made many important discoveries, and had intended to publish a comprehensive treatise on human anatomy. For instance, he produced the first accurate depiction of the human spine, while his notes documenting his dissection of the Florentine centenarian contain the earliest known description of cirrhosis of the liver and arteriosclerosis. He was the first to develop drawing techniques in anatomy to convey information using cross-sections and multiple