After childbirth, prolactin levels fall as the internal stimulus for them is removed.

"A strong feeling caused by internal or external stimuli."

In the mid-1400s, due to the lack of internal and external stimuli, Ukraine's education system slipped into decay.

The internal stimulus is driven by the inner drive to work towards each individuals aspiration.

The environment consists of internal and external stimuli that surround an individual or group.

He glanced down at her hands and saw, for the first time, how they were twitching, as if in response to some internal stimulus.

Laughing is an involuntary reaction to certain external or internal stimuli.

An internal stimulus is often the first component of a homeostatic control system.

One internal stimulus that causes hormone release is blood pressure.

The digestive system is also able to respond to internal stimuli.