In this case, the damper is normally opened by the force of the spring but can be closed by the force of the motor. Removal of electrical power re-opens the damper. This style of damper is advantageous because it is fail safe; if the control to the damper fails, the damper opens and allows air to flow.
The adrenal glands, located on the top of each kidney, are responsible for releasing different classes of hormones. The outer part of the gland, called the adrenal cortex, produces the hormones cortisol (pronounced KAWR-tuh-sohl) and aldosterone (pronounced al-DOS-tuh-rohn). The inner part of the gland, called the adrenal medulla (pronounced muh-DUHL-uh), produces the hormones adrenaline and noradrenaline.
The adrenal glands are located just on top of the kidneys. The adrenals are an integral part of the endocrine system. The medulla, which is the inner part, pours out epinephrine (adrenaline) and norepinephrine. These hormones speed up the body's metabolism in order to help us to cope with stress.