Explain the roles of the autonomic nervous syst... - SS3 Biology Nervous System In Man Question

The human nervous system is further divided into the autonomic nervous system (ANS) and the somatic nervous system (SNS), each serving distinct functions in maintaining homeostasis. The autonomic nervous system regulates involuntary activities of internal organs and glands. It consists of two branches: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic division prepares the body for "fight or flight" responses during stressful or dangerous situations. It increases heart rate, dilates pupils, and diverts blood flow to muscles, enabling quick reactions. Conversely, the parasympathetic division promotes "rest and digest" responses, conserving energy and aiding in digestion, reducing heart rate, and constricting pupils. On the other hand, the somatic nervous system controls voluntary movements and sensory information. It allows individuals to interact with the external environment through conscious actions. Sensory neurons convey information from the senses to the CNS, while motor neurons carry signals from the CNS to muscles, enabling precise movements. The ANS and SNS work together to maintain internal balance (homeostasis) in the body. For instance, when the body experiences stress (e.g., running from a predator), the sympathetic system activates to increase heart rate and release adrenaline, while the parasympathetic system later counteracts this response, slowing down the heart rate once the threat has passed.