Answer:
The nerves that control voluntary responses like those connected to your muscles are part of the Somatic nervous system.
If you are dehydrated, your kidney will retain some water.
Explanation:
From the central nervous system, the motor nerves which supplies to the voluntary muscles like skeletal muscle forms the somatic nervous system. Whereas those motor nerves from CNS which supplies to the visceral organs or involuntary organs like smooth muscles and glands forms the part of autonomous nervous system. In case of ANS, motor nerves starts from the CNS, synapse within ganglia, another neuron starts from ganglia and innervates the target muscle or organ. ANS is further classified into sympathetic and parasympathetic nervous system.
When a person is dehydrated in order to maintain the water levels within the body, some water is retained with the help of kidneys. The basic functional unit of kidney i.e. nephrons help in active and passive re-absorption of water. During dehydration, the low blood pressure stimulates the anti diuretic hormone (ADH) which helps in retaining water by binding to the receptors on distal convoluted tubules (DCT) and collecting duct of nephron. ADH stimulates reabsorption of water from DCT thereby making the urine more concentrated.
