The gland that secreted the hormone that made Janelle respond as such would be the adrenal gland.
The adrenal gland is responsible for the secretion of hormones such as cortisol, adrenaline, and aldosterone. These hormones have a wide variety of functions that help maintain the normal body system
Of particular importance is adrenaline in the fight or flight response of humans. It makes major blood vessels contract and redirects blood to the heart - thus causing the heart to beat faster.
Hence, Jenelle's response would have been due to the adrenal gland producing the adrenaline hormone.
More on adrenaline can be found here: https://brainly.com/question/3462016
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