While working in a lab without protective glasses, a researcher accidentally sprays themselves in the eyes with a nerve agent that blocks contraction in smooth muscles. Choose the statement that correctly reflects how the eyes will be affected.
A)The only effect is that the ciliary body won't be able to adjust the lens.
B)The only effect is that the iris won't be reactive to light.
C)Neither the ciliary body nor the iris will be able to adjust or react.
D)Neither the ciliary body nor the iris will be able to adjust or react. The extrinsic eye muscles won't be able to move the eye, either.

Question

Quizplus · Accepted Answer

Nerve agents that block contraction in smooth muscles would affect both the ciliary body, which is responsible for adjusting the lens of the eye for focusing, and the iris, which controls the diameter of the pupil and thus its reaction to light. The extrinsic eye muscles, which move the eye, are not composed of smooth muscle but rather skeletal muscle, so they would not be affected by such an agent.

While Working in a Lab Without Protective Glasses, a Researcher