2006-10-06 03:39:26 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Biology
For the most part they are. However, everyone has a preference for the use of one side over the other. As you use your muscles your body adapts to bring blood to the parts that need it most. Therefore, the growth patterns become asymmetrical.
2006-10-06 03:42:28 · answer #1 · answered by Anonymous · 0⤊ 1⤋
Blood vessels aren't symmetrical because they have varying functions based off of your internal organs' layout. Because you only have one of some organs (heart, pancreas, liver, gut, etc.) and a limited amount of space, some have to go on one side, and the others on the other side.
Keep in mind that blood vessels also have to travel to and from each internal organ, so that they get fresh blood in, and used blood out. Thus, since all of the internal organs were not placed with bilateral symmetry as the exterior of your body, it wouldn't work. You'd have to have some organs' blood vessels wrapping around halfway backwards so that they could approach the heart and lungs from the proper direction if you had symmetrically arranged organs.
Remember, the layout of the blood vessels has to accomodate each organ's _place_ and _direction_ of blood flow while still managing to tie in properly to the pump (heart) and the O2 exchange (lungs).
2006-10-06 14:10:30 · answer #2 · answered by christophermalachite 3 · 0⤊ 0⤋
The human body is only externally symmetrical and proportionate for balancing reasons, but the internal organs are not because they don't need to be so. You have one heart on the left side, although your nose is in the middle of your face etc. In a creature nothing is the way it is without a reason, and blood vessels have no reason to be symmetrically placed.
2006-10-06 10:54:30 · answer #3 · answered by lucantropeea 2 · 1⤊ 0⤋
there are several "unpaired organs" ( e.g. heart, liver, spleen, etc ) as well as the digestive tract ( which is asymetric ).
these organs do not exist on the midline of the body and therefore require a blood supply that differs from left to right.
the reason these organs are not on the midline is because embryonic development is not generally a symmetric process ( e.g the embryo needs to attach itself onto the womb wall which inherently makes it asymmetric ( wall side vs. womb side )
hope your question was addressed :)
2006-10-06 10:48:44 · answer #4 · answered by fullbony 4 · 1⤊ 0⤋
Because the layout of your internal organs isn't symmetrical.
2006-10-06 10:40:56 · answer #5 · answered by bonshui 6 · 0⤊ 0⤋
bodies aren't accurately symmetrical anyway. Most limbs etc. are slightly longer/shorter/different.
2006-10-06 10:44:08 · answer #6 · answered by Anonymous · 0⤊ 1⤋