What is a Promise Ring. A promise ring, sometimes known as a pre-engagement ring, is a simple piece of jewelry that is given as a symbol of a committed, monogamous relationship. In some cases, the promise ring symbolizes purity and a decision to remain celibate until marriage.
Noun. 1. external respiration-the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation. breathing, respiration, ventilation. artificial respiration-an emergency procedure whereby breathing is maintained artificially.
This process provides oxygen into the cells from the blood and removes carbon dioxide from the cells. External respiration is the exchange of oxygen and carbon dioxide between the blood and fresh air and this occurs in between the alveoli of the lungs and the capillaries of the pulmonary circulatory system.External respiration is important, mainly to oxygenate the blood and to remove carbon dioxide from the blood.his process provides oxygen into the cells from the blood and removes carbon dioxide from the cells. External respiration is the exchange of oxygen and carbon dioxide between the blood and fresh air and this occurs in between the alveoli of the lungs and the capillaries of the pulmonary circulatory system.