Ciliary epithelium, autonomic control

Structures of the anterior chamber of the eye. Tissues with significant autonomic functions and the associated ANS receptors are shown in this schematic diagram. Aqueous humor is secreted by the epithelium of the ciliary body, flows into the space in front of the iris, flows through the trabecular meshwork, and exits via the canal of Schlemm arrow). Blockade of the 13 adrenoceptors associated with the ciliary epithelium causes decreased secretion of aqueous. Blood vessels (not shown) in the sclera are also under autonomic control and influence aqueous drainage. 

Complex organ control— the eye The eye contains multiple tissues with various functions, several of them under autonomic control (Figure 6-5). The pupil, discussed above, is under reciprocal control by the SANS (via alpha receptors) and the PANS (via muscarinic receptors) acting on two different muscles in the iris. The ciliary muscle, which controls accommodation, is under primary control of muscarinic receptors innervated by the PANS, with insignificant contributions from the SANS. The ciliary epithelium, on the other hand, has important beta receptors that have a permissive effect on aqueous humor secretion. 

The eye is a good example of an organ with multiple autonomic nervous system (ANS) functions, controlled by several autonomic receptors. As shown in Figure 6-9, the anterior chamber is the site of several autonomic effector tissues. These tissues include three muscles (pupillary dilator and constrictor muscles in the iris and the ciliary muscle) and the secretory epithelium of the ciliary body. 

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