ganglion

noun ganglion

• focal point — Also called principal focus. Optics. either of two points on the axis of a mirror, lens, or other optical system, one point being such that rays diverging from it are deviated parallel to the axis upon refraction or reflection by the system and the other point being such that rays parallel to the axis of the system converge to the point upon refraction or reflection by the system.
• command post — A command post is a place from which a commander in the army controls and organizes his forces.
• headquarters — a center of operations, as of the police or a business, from which orders are issued; the chief administrative office of an organization: The operatives were always in touch with headquarters.
• core — The core of a fruit is the central part of it. It contains seeds or pips.
• focus — a central point, as of attraction, attention, or activity: The need to prevent a nuclear war became the focus of all diplomatic efforts.