This action causes mucous to discharge from the nose and may run down the back of the throat in order to prevent these substances from causing infection or irritation. Runny nose may be triggered by other conditions such as allergies, a cold or the flu, infections or particular medicines.
The largest veins in the human body are the venae cavae. The superior vena cava carries blood from the arms and head to the right atrium of the heart. The inferior vena cava carries blood from the legs and abdomen to the heart.n the circulatory system, veins (from the Latin vena) are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart.
The great saphenous vein (GSV) , previously also called the long saphenous vein, is a large, subcutaneous, superficial vein of the leg.It is the longest vein in the body running along the length of the leg.tructure [edit]. The great saphenous vein originates from where the dorsal vein of the big toe (the Hallux) merges with the dorsal venous arch of the foot. After passing in front of the medial malleolus (where it often can be visualized and palpated), it runs up the medial side of the leg.