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Vein valves and varicose veins. Pressure in veins is very low. Pressure in veins is very low Problem: how get blood all the way from toes back to heart?. “Spider veins” are usually in capillaries (not veins) Much smaller May appear red, purple, or blue Usually don’t indicate any problem
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Pressure in veins is very low • Problem: how get blood all the way from toes back to heart?
“Spider veins” are usually in capillaries (not veins) • Much smaller • May appear red, purple, or blue • Usually don’t indicate any problem • If new ones come up frequently – mention to your doctor
Valves usually prevent backflow • Muscular action squeezes blood back to the heart • Leaky valves allow blood to flow back “down” • Prolonged standing; • Pregnancy • Lack of exercise • Age • Strenuous muscular work can cause some • obesity • Blood forms “pool” in veins • Can lead to clots • Clots can break off and spread through body • These clots can cause heart attack or stroke
When breathing, diaphragm moves up and down • Diaphragm squeezes blood in vena cava up to right atrium exhale Work harder inhale Breathe faster More blood returned to heart