Complete the five sentences about the eye and the nervous system. Structures in the eye alter the shape of the lens so the eye can focus on near and far objects. This is called [BLANK]. The radial and circular muscles in the iris are a pair of [BLANK] muscles that act against each other. Muscles in the eye are under the control of the nervous system. The [BLANK] nervous system has only sensory and motor neurones. The [BLANK] nerve from the eye contains sensory neurones that carry impulses to the [BLANK].
Transmission of impulses depends on ions moving through the cell membranes of neurones down their concentration gradients. Active transport maintains the concentration gradients of ions across neurone membranes. Explain how ions are moved across membranes by active transport.
Use the information in Fig. 3.1 and Table 3.1 to Explain the effects of these two drugs on the nervous system.
Discuss the arguments opposing the use of anabolic steroids in sport.