Final answer:
The drug Ritalin typically produces mydriasis, which is the dilation of the pupils, as it increases levels of norepinephrine in the brain.
Step-by-step explanation:
The drug Ritalin, which is a brand name for methylphenidate, is a central nervous system stimulant. It works by increasing the availability of the neurotransmitters norepinephrine and dopamine in your brain, which helps to increase attention and reduce impulsivity in people with ADHD. Considering the pharmacological effects of stimulants like Ritalin, it can lead to several physiological changes. According to the information provided, norepinephrine, a neurotransmitter released by the sympathetic nervous system, can cause pupillary dilation when it binds to adrenergic receptors in the iris smooth muscle. This process is referred to as mydriasis. Therefore, Ritalin will usually produce mydriasis rather than bradycardia, nystagmus, or miosis.