Biological Systems MCAT Practice Exam

During which phase of the sexual act does the sympathetic nervous system become active?

1. Resolution phase

2. Arousal phase

3. Orgasm phase

4. Refractory phase

The correct answer is: Orgasm phase

The correct answer reflects the role of the sympathetic nervous system during the orgasm phase of the sexual act. During this phase, there is a surge of activity from the sympathetic nervous system, which is responsible for the physiological responses associated with orgasm, such as increased heart rate, blood pressure, and muscle contractions in the pelvic area. The orgasm phase typically involves both psychological and physical sensations that are mediated by this nervous system's activation. These include pleasurable feelings, involuntary muscle contractions, and hair-raising responses, all underlined by the release of endorphins and other neurochemicals that heighten the overall experience. In contrast, during the resolution phase, the body gradually returns to its baseline state, which is primarily governed by the parasympathetic nervous system. This system is associated with calming processes, such as reduced heart rate and blood pressure. The arousal phase is characterized by increased blood flow and stimulation, mainly driven by the parasympathetic system, preparing the body for sexual function. The refractory phase, which follows orgasm in males, can involve a temporary period during which further sexual arousal is difficult or impossible, further indicating predominance of the parasympathetic nervous system in returning to a resting state. Thus, the distinctive