Final answer:
The two functional divisions of the nervous system are the somatic and autonomic nervous systems, which control voluntary movements and involuntary functions respectively, with the autonomic system further splitting into sympathetic and parasympathetic divisions for homeostasis.
Step-by-step explanation:
The two functional divisions of the nervous system are the somatic nervous system and the autonomic nervous system. The somatic nervous system is responsible for voluntary control of body movements through the action of skeletal muscles, and the autonomic nervous system regulates involuntary functions such as heart rate, digestion, and respiratory rate. The autonomic nervous system is further divided into the sympathetic and parasympathetic nervous systems, which work antagonistically to maintain homeostasis.
To explain further, the somatic nervous system is involved in processing sensory information that leads to conscious perception and voluntary muscle movements. On the other hand, the autonomic nervous system controls physiological functions without conscious control. Within the autonomic nervous system, the sympathetic division prepares the body for 'fight or flight' responses, while the parasythetic division supports 'rest and digest' activities, therefore balancing the body's response to different situations.