sympathetic nervous system

1. The part of the autonomic nervous system that tends to act in opposition to the parasympathetic nervous system, as by speeding up the heartbeat and causing contraction of the blood vessels. It regulates the function of the sweat glands and stimulates the secretion of glucose in the liver. The sympathetic nervous system is activated especially under conditions of stress.

2. Compare parasympathetic nervous system

Example Sentences

When the body hyperventilates, the sympathetic nervous system is activated, triggering the body’s “fight or flight” response.

From Salon

It turns the human brain into a reptilian one and activates the sympathetic nervous system, putting us into fight-or-flight mode — the same one we can get stuck in when we’re chronically lonely.

From Salon

"Patients with HD have a slightly more active sympathetic nervous system, which is what drives the fight or flight response, and theoretically have more norepinephrine," Schultz explains.

From Science Daily

Imai’s team discovered that those neurons send signals to the animal’s fat stores via the sympathetic nervous system, a network of nerves carrying messages from the brain throughout the body.

From Science Magazine

The resulting activation of the sympathetic nervous system could interfere with sleep, drive inflammation, and disrupt glucose regulation, he adds, all of which have downstream health effects.

From Science Magazine