A little exercise never hurt anyoneâand it may even release some endorphins to boost that post-hangover mood. Differential effects of acute and regular physical exercise on cognition and affect. Hopkins ME, Davis FC, Vantieghem MR.
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.
Varicose veins. For other uses, see Varices. Varicose veins are veins that have become enlarged and twisted. The term commonly refers to the veins on the leg, although varicose veins can occur elsewhere. Veins have pairs of leaflet valves to prevent blood from flowing backwards (retrograde flow or venous reflux). Leg muscles pump the veins to return blood to the heart (the skeletal-muscle pump), against the effects of gravity.