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.
Anatomy of the Respiratory System. The respiratory system is responsible for gaseous exchange between the external atmosphere and the blood. It delivers oxygen to the circulatory system for distribution to all body cells and aids in the removal of carbon dioxide.The major organs of the respiratory system are the nose, pharynx, larynx, trachea, bronchi and their smaller branches, and the lungs that contain air sacs called alveoli.t delivers oxygen to the circulatory system for distribution to all body cells and aids in the removal of carbon dioxide. The major organs of the respiratory system are the nose, pharynx, larynx, trachea, bronchi and their smaller branches, and the lungs that contain air sacs called alveoli.