1 An unopened container should last for 1-3 months at 40Â°F or less in the refrigerator, but some companies guarantee their product for up to 6 months.  If left in its partially-open original paper wrap, the exposed area of stick butter will begin to harden and smell stale after about a week, as oxygen sets in.
Quick Answer. Humans need a respiratory system because it is made up of organs that allow them to breathe. Breathing delivers oxygen to the body and takes away carbon dioxide. Every cell in the body needs oxygen to obtain energy from food. Continue Reading.
The Respiratory SystemIn human body, the respiratory system is an essential system that helps perform the task of gas exchange. The inhalation of oxygen and the exhalation of carbon dioxide are done via this system.Anatomically, the respiratory system can be described as a series of air passages or tubes of various sizes that help conduct air into the lung tissues (alveoli).This system includes the two lungs, nasal airways, and surrounding respiratory muscles.he inhalation of oxygen and the exhalation of carbon dioxide are done via this system. Anatomically, the respiratory system can be described as a series of air passages or tubes of various sizes that help conduct air into the lung tissues (alveoli).