Final answer:
The sympathetic system readies the body for 'fight or flight' and indirectly affects skeletal muscle through hormonal signals like epinephrine, enhancing oxygen delivery and altering blood flow and metabolism. The parasympathetic system has an insignificant direct role on skeletal muscle, focusing on 'rest and digest' functions.
Step-by-step explanation:
How the Sympathetic and Parasympathetic Systems Act on Skeletal Muscle:
The sympathetic and parasympathetic nervous systems typically exert opposing effects on various organs and systems within the body. In the context of skeletal muscles, the sympathetic nervous system prepares the body for 'fight or flight' responses, leading to increased oxygen delivery to skeletal muscles through heightened respiratory and cardiovascular activity. However, skeletal muscles are generally not directly innervated by the sympathetic nervous system. Instead, they are primarily controlled by somatic motor neurons. Yet the sympathetic system does influence skeletal muscle indirectly. During stress or vigorous activity, epinephrine and norepinephrine released from the adrenal gland into the bloodstream, as a result of sympathetic activation, can alter blood flow and metabolic rates in skeletal muscle. In contrast, the parasympathetic system does not have a direct role in controlling skeletal muscle, as it mainly promotes 'rest and digest' activities, such as lowering the heart rate and stimulating digestion. Therefore, the parasympathetic system's action on skeletal muscle is not significant.