As you are waiting to be interviewed for a job, your heart rate, body temperature, and breathing rate begin to increase. these physiological changes are produced by activation of the nervous system.

sympathetic nervous system.

Explanation:

The nerves of the sympathetic nervous system usually release a substance - noradrenaline - that promotes reactions associated with an alertness: acceleration of the heartbeat and increased respiration rate and rhythm, inhibition of digestive system functioning, release of glucose to the blood by the liver, pupil dilation, among others.

In the Sympathetic Autonomic Nervous System, nerves depart from the spinal cord and nerve ganglia parallel to the medulla are distanced from the organs innervated by them. The nerve nuclei - groups of nerve cells - of the sympathetic system are located in the thoracic and lumbar portions of the spinal cord. Axons of these neurons exit through the anterior roots of the spinal cord nerves of these regions.

answer: because barriers look like ball

explanation: there round and blue like my ball