The parasympathetic nervous system <span>conserves energy as it slows down heart rate, increases intestinal and glandular activity, and relaxes the sphincter muscles of the gastrointestinal tract. It gets the nickname "rest and digest" for doing exactly so. Typically most active when sleeping, however is also the explanation for post-prandial fatigue, or being tired after eating (especially a large meal).</span>
        
             
        
        
        
Answer: positive sodium ions
Explanation:
This relates to the Action Potential which is what a nerve cell goes through when it needs to send information down the nerve cell to another cell and so on till it gets to the destination of the message. 
The information is transmitted when the segments of the axon fire and when they do, positive sodium ions come in from outside the cell to the inside thereby making the inside positive. The previous segment would return to a resting potential when potassium ions which are negative, rush into the cell. 
 
        
             
        
        
        
Answer;
-Glycogen 
The organic molecule called glycogen is formed of branched chains of sugar units.
Explanation; 
-Glycogen is a branched polysaccharide of glucose that serves as a form of energy storage in humans, animals, fungi, and bacteria.
-In humans, glycogen is made and stored in liver and muscle cells. Muscle cell glycogen is broken down into glucose, and liver glycogen is broken down into glucose as a circulating energy source glucose for use by the body.
-Glycogen is accumulated in response to insulin and broken down into glucose in response to glucagon. It plays a major role in maintaining the blood-glucose levels, which is vital since some organs in the body such as the brain purely depend on glucose for energy.