0
I assume you mean "Why do veins in the head and face lack valves?"
The answer is due to being organisms with upright posture. You need valves in your legs to keep the blood from falling down to your feet, and instead propel the blood to your heart. Your head, though, is above your heart, so you don't want valves trapping the blood in the head. That would cause headaches and perfusion issues. So lacking valves allows blood to flow down to the heart.
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
If compressor has faulty valves the head pressure would be?
broken
What are the three main part of your body?
That would be the head,thorax/chest and abdomen.
What does it mean when you scratch your head a lot but you dont have lice?
That means that you probley have dandruff. Or just that her head is itchy.
What sends blood to heart from upper body?
Veins always carry blood to the heart. Most carry blood low in oxygen but some don't. The term artery and vein are anatomical terms only. Here is a list: internal jugular (from head), left and right subclavian (from upper chest), brachiocephalic (from arm and face), and superior vena cava.
Can you see your face?
A human cannot. The only parts of the face you can see are the nose, cheeks, and mouth; which can be done by looking down without moving your head.
What do veins have to prevent blood from flowing backward?
One-way valves prevent the back flow of bloodThere are tiny one way valves throughout a vein. These stop blood from flowing backwards. Interestingly, when these valves in veins in the legs malfunction, the result are varicose veins.
Why do veins in the head of a human have no valves?
The veins in your head dont need valves. Valves prevent backflow in the lower extremities because your bloodflow is going against gravity and your body is using muscular pumps to get the bloodflow back up to the heart. The blood flow in your upper extremities use gravity to get back to the heart via the superior vena cava.
What are the two veins in the head and neck that lack valves?
Facial and Pterygoid plexus of v.
Vein to pulsating out of the head?
Pulsing veins are a sign of stress. I have the same thing. All over my head and face I can feel veins pulsing and can even see them pulsing at the temples and beneath my eyes.
What area do the right and left external jugular veins drain?
posterior head (musculature and skin of the scalp and face)
What is a superficial vein in the leg?
The superficial veins of the legs connect to the deep veins through "penetrating veins" which run perpendicular to the skin from one to the other. The deep veins are essentially 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. When one of these valves goes bad the high pressure is allowed to go back to the superficial veins which blow up like balloons and become visible as what we call varicose veins (or "spider veins").
Why are valves found between the chambers in the heart and veins throughout the body but not in arteries?
There are valves in veins to prevent backflow. The blood pressure in veins is relatively low and, particularly in the legs and arms, can tend to pool if allowed to backflow. In contrast, there is relatively high blood pressure in the arteries, which prevents the need for valves to control backflow.
Is there veins were your Monroe piercing gos?
Yes there are veins in the face, actually the face and head are almost covered by veins, that's why head injuries bleed so badly. If you are asking with intent on trying to do your own Monroe piercing think again, besides veins there are several nerve bundles that run in the same area so do your self a favour leave the piercing to a professional body piercer working in a licensed and inspected facility. Please
Dangerous triangle of the face?
The dangerous triangle of the face consists of the area from the corners of the mouth to the bridge of the nose, including the nose and maxilla. Due to the special nature of the blood supply to the human nose and surrounding area, it is possible (although very rare) for retrograde infections from the nasal area to spread to the brain.This is possible because of venous communication (via the ophthalmic veins) between the facial vein and the cavernous sinus. The cavernous sinus lies within the cranial cavity, between layers of the meninges and is a major conduit of venous drainage from the brain.It is a common misconception that the veins of the head do not contain one way valves like other veins of the circulatory system. In fact, it is not the absence of venous valves but the existence of communications between the facial vein and cavernous sinus and the direction of blood flow that is important in the spread of infection from the face
What causes you face to turn red when stand on your head?
When you stand on your head (though i dont know why) all the blood rushes to your head thus turing the color of your head red.
What is and e valve?
There are two types of valves in an engine. The valves are located in the head. There are exhaust valves and fuel intake valves
Why would your 1999 Silverado lose coolant?
intake blown,there plastic and are famous for that, only needs to be replaced and you wont have anymore problems,if you dont youll have sticking valves,etc. coolant going to head, sticking valves
