Areolar Tissue is loose connective tissue that consists of a meshwork of collagen, elastic tissue, and reticular fibres-with many connective tissue cells in between the meshwork of fibres. The fibres that form the mesh structure of areolar tissue include:
Normal growth rates for Emerald Green (Thuja occidentalis 'Smaragd') are between 6 to 12 per year once established and tapering off as they reach about 12' to 15'. I'd be suprised to see more than about 18 per year even in ideal conditions.
Other varieties are even taller: It's a stretch to call Pyramidal arborvitae (Thuja occidentalis Pyramidalis) a shrub, when it shoots up to some 60 feet tall and 15 feet wide in zones 3 through 8. Both of these arborvitae grow faster than seems possible.