Bloody or tarry stools refer to a stool sample thatâs either dark red or black in color. Bloody or tarry stools can indicate bleeding or other injuries in your gastrointestinal tract. You may also have dark, discolored bowel movements after eating dark-colored foods.
The longest vein in the body is the great saphenous vein, a superficial vein found in the leg.he deep veins are essenti â¦ ally a column of blood running from your head to you feet and so when one is standing are under high pressure. In order to keep this pressure away from the frail superficial veins the penetrating veins have valves.
Vein Types. Veins can be categorized into four main types: pulmonary, systemic, superficial, and deep veins. Pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart. Systemic veins return oxygen-depleted blood from the rest of the body to the right atrium of the heart. Superficial veins are located close to the surface of the skin and are not located near a corresponding artery.