which of the following biological systems is most likely responsible for an increase in heart rate while experiencing anxiety?

The biological system most likely responsible for an increase in heart rate while experiencing anxiety is the sympathetic nervous system , a branch of the autonomic nervous system.

Quick Scoop

When a person feels anxiety, the body’s built‑in “fight or flight” response switches on, which strongly activates the sympathetic nervous system. This system signals the heart to beat faster and harder, raising heart rate and blood pressure so the body can respond to a perceived threat.

What The Sympathetic System Does

• Releases catecholamines like epinephrine (adrenaline) and norepinephrine, which stimulate the heart and blood vessels.

• Increases heart rate, blood pressure, and redirects blood flow toward muscles and vital organs during stress or anxiety.

In short, during anxiety, it is the sympathetic nervous system —not the digestive, reproductive, or skeletal system—that primarily drives the racing heartbeat you feel.

TL;DR: The correct answer is the sympathetic nervous system. Information gathered from public forums or data available on the internet and portrayed here.