The organization of microfibrils forming the primary cell wall is rather disorganized. It has a broad range of transduction including many primary cell types and stem cells. The most common hemicellulose in the primary cell wall is xyloglucan. Cellulose microfibrils are laid down in the inner surface of the primary cell wall. The design of the sugar battery is based on the theory of the primary cell. As such, the device acts as a primary cell. Neuron is one of the primary cell types in the nervous system. The primordial pit is the only aperture in the otherwise continuous primary cell wall. In many dicotyledonous plants, it is the most abundant hemicellulose in the primary cell wall. The cell wall is a very thin primary cell wall. Thick primary cell walls enclose and protect the aleurone cells. The parathyroid chief cell is the primary cell of the parathyroid gland. Both non-rechargeable primary cell and rechargeable secondary cell chemistries have been investigated. With the exception of some derived from tumors, most primary cell cultures have limited lifespan. The primary cell types "Leishmania" infiltrates are phagocytotic cells such as neutrophils and macrophages.