How does the brain and spinal cord, cerebral cortex, and hypothalamus regulate autonomic responses?
The autonomic nervous system is involuntary, controlling the smooth and cardiac muscles, and the organs of the digestive, circulatory, excretory and endocrine systems. The autonomic nervous system consists of the sympathetic division(which primes the body for digesting food and resting) and parasympathetic division(which prepares the body for intense, energy-consuming activities). Parasympathetic and sympathetic neurons emerge from different regions of the CNS, and use different neurotransmitters. Most parasympathetic neurons emerge from the brain and lower part of the spinal cord and produce their effects by releasing the neurotransmitter acetylcholine at synapses with target organs. Neurons of the sympathetic system emerge from the middle regions of the spinal cord and release norepinephrine at target organs.
