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Why do veins dilate?
Veins contract and expand in response to blood pressure.
What is the different between viens and arteries?
Veins take blood to the heart, while arteries take blood away from the heart. Also, veins have valves that don't allow backflow because their wall contains almost no smooth muscle to pump the blood - they cannot constrict and dilate on their own. Veins rely on the body's muscular movement to move the blood contained in them. Arteries, however, can constrict or dilate to diver blood flow to different parts of the body and to keep blood pressure relatively constant. They have a large smooth muscle component in their walls.
Why veins are cylindrical?
Because this shape works for the body. Somewhere in the evolution time line the creature which had the first cylindrical blood vessel survived and that information has been stored in the DNA and has past it on to its offspring. The reason I believe it works is that it is the easiest shape to dilate or constrict.
Why do your veins in your legs dilate when playing golf in the heat?
Your skin is like your body's air conditioner. When it is hot, you "open" your vents (dilate blood vessels). When it's cold, you close it up (constrict, which gives your skin a "bluish" appearance). If you are golfing, you are using a lot of energy in your legs creating a lot of heat. Therefore, your body will open up those "vents" the most.
Structural similarities between arteries and vein?
Structural similarities between artries and veins are1) The walls of arteries and veins both contain collagen which makes them strong and durable.2) They both contain elastic fibres which allow them to stretch and recoil.3) Their walls contain smooth muscles that enable them to constrict and dilate.4) They are both three - layered.
Ways to encouraging veins to dilate?
Heat or warmth and movement like lite excercise
Why are females at greater risk of varicose veins than males?
It is thought that female sex hormones contribute to the development of varicose veins by making the veins dilate more easily.
What happens to the heart when you exercise?
Muscles need more oxygen and glucose during exercise.They dilate their arteries to receive more blood . At the same time,working muscles push more blood in the veins to the heart.This increases the volume of blood reaching the heart.The heart therefore has to pump harder and faster.
If a person doesn't exercise will they get blue veins and Can they die?
Not every person who doesn't exercise will get blue veins
What disorder leads to the formation of spider veins?
The blood pressure in the superficial veins is usually low, but if it rises and remains at a higher level over a period of time, the valves in the veins begin to fail and the veins dilate, or expand
What tissue in arteries and veins permits them to constrict?
Smooth muscle contained with the tunica media layer of their walls.
Why do varicose veins itch?
Varicose veins are filled with an abnormal amount of blood. Nerve irritation is what causes them to itch. They press against adjacent nerves as they dilate.
