Answer:
The enteric nervous system, which is a part of the peripheral nervous system will slow down digestion to conserve energy. The enteric nervous system controls the gastrointestinal system.
Step-by-step explanation:
The Central nervous system (brain and spinal cord) and peripheral nervous system (neurons and ganglia) are the divisions of human nervous system. The peripheral nervous system (PNS) is the portion of the nervous system which is outside the central nervous system (CNS) , and connects the CNS to the rest of the body. The divisions of PNS are somatic, autonomic, and enteric nervous systems. The autonomic nervous system is again classified as sympathetic and the parasympathetic nervous systems. The sympathetic nervous system is activated during body's fight or flight condition to mobilize energy, which gets the body aroused and ready for action while the parasympathetic nervous system returns the body to a normal, non-aroused state.The enteric nervous system is capable of acting independently of the sympathetic and parasympathetic nervous systems and controls the gastrointestinal system.
When a person perceives danger, it causes the body to go into a fight or flight response as the sympathetic nervous system is activated. The enteric nervous system slows down the digestion to conserve body's energy so that all the energy is diverted to face the threat. The activated sympathetic nervous system releases a chemical called adrenaline (epinephrine) into the bloodstream. The circulation of adrenaline causes several physiological changes like heart to beat faster than normal, high blood pressure, pushing blood to the muscles, heart, and other vital organs, rapid breathing, increasing alertness, sharper sense etc. It also triggers the release of glucose and fats from temporary storage sites (liver) in the body into the bloodstream, supplying energy to all parts of the body and prepares it for fight or flight. The parasympathetic nervous system helps to returns the body to a normal state.