Read each description below regarding the dual innervation of the ANS. Match the appropriate category based on whether it is an example of antagonistic or cooperative innervation.

a. The sympathetic division stimulates mucus production by salivary glands while the parasympathetic division stimulates enzyme secretion.
b. The sympathetic division stimulates an increase in heart rate while the parasympathetic division stimulates a decrease in heart rate.
c. During sex, the parasympathetic division stimulates arousal while the sympathetic division stimulates orgasm.
d. The parasympathetic division constricts the pupils while the sympathetic division dilates the pupils.

1. Antagonistic
2. Cooperative

The autonomic nervous system (ANS) is a control system that is responsible for controlling the body's unconscious functions (e.g., digestion, respiratory rate, heart rate, pupillary response, sexual arousal, etc). The ANS is divided into the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system comprises nerves from the thoracic and lumbar segments of the spinal cord (responsible for fight or flight); whereas the parasympathetic nervous system is composed primarily of the cranial and sacral spinal nerves (responsible for controlling many of the body's functions when it is at rest). Moreover, antagonistic innervation occurs when an organ is controlled by two different types of nerves, i.e., dual innervation of the organ by both divisions of the ANS, where the effects of the sympathetic and parasympathetic divisions are antagonistic (i.e., they oppose each other). On the other hand, there are situations where the dual innervation results in a unilateral cooperative response (for example, the urinary system is innervated by parasympathetic and sympathetic nerve fibers that exhibit cooperative effects).