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 is a superficial vein that runs through the subcutaneous tissue layer deep to the dermis and superficial to the skeletal muscles of the foot and leg.... Click to read more below. The great saphenous vein is the major superficial vein of the medial leg and thigh.It is the longest vein in the human body, extending from the top of the foot to the upper thigh and groin.The great saphenous vein plays an important role in returning blood from the superficial tissues of the leg to the heart and is also used in several medical procedures due to its size and superficial location.t the top of the thigh, it passes through the saphenous opening of the fascia lata and enters the deeper tissues of the upper thigh before merging into the femoral vein. An extensive network of superficial veins connects to the great saphenous vein throughout its length.