In certain cities, too, traditional farms and other forms of urban farming - such as crops grown on rooftops or vacant lots - may only be 60 to 100 miles away, close enough to compete with vertical farms. Vertical-farming projects have sprouted up in several North American cities as well as in the Netherlands, Scandinavia, Germany, Korea, Japan, Abu Dhabi and Singapore among others.
Deoxygenated blood enters the right atrium through three major veins: the superior and inferior vena cava and the coronary sinus. The superior vena cava returns all of the blood to the heart from tissues superior to the heart in the head, neck, arms and upper thorax. Likewise, the inferior vena cava returns blood to the heart from tissues inferior to the heart, including the legs, abdomen and lower thorax.
The Inferior vena cava-just like the Superior vena cava -, returns blood to the heart. When blood is returning to the heart, that blood is already circulated in the body, therefore it is already downloaded the oxygen to the body tissues, and picked up the carbon dioxide from them.he Inferior vena cava-just like the Superior vena cava -, returns blood to the heart. When blood is returning to the heart, that blood is already circulated in the body, therefore it is already downloaded the oxygen to the body tissues, and picked up the carbon dioxide from them.