Asymmetries of the Human Body

The human body is said to possess bilateral symmetry. But I read today that the right lung has three lobes, while the left one only has two. I suppose this is to make room for the heart and its associated plumbing, which is not bilaterally symmetric. And of course, the colon goes up one side of the body but down the other, and the little section that leads to the rectum has no counterpart on the other side of the body. Also, the right testicle tends to hang lower than the left, but only in about two out of three men. Tailors and sculptors seem to be excessively interested in this.

Are there any other consistently asymmetric features of the human body?

Almost everything in the torso is typically asymmetrical. The heart, lungs, pancreas, spleen, liver and gal bladder, stomach, intestines, and vasculature.

Your whole body is assymetrical. One arm and one leg is invariably both more muscular and shorter than the other. Various brain structures are either less developed or absent on one side or the other.

According to your link (and other sources) the left testicle is normally lower.

Take a full frontal (digital) photograph of the face. Then use a graphics program to split the image vertically so as to create two faces, one of the left side and its mirror and a second of the right side and its mirror. Now compare those two images with each other and with the original.
[li]Random Web Example Number One.[/li][li]Random Web Example Number Two.[/li][/ul]

Only tangentially related, but there’s a congenital condition, situs inversus, in which the organs in the thorax and abdomen are reversed/mirrored from their normal position.

I have done this with my entire body (no, I’m not going to show you), and the results are amazing. I already knew that there is no part of my body that’s symmetrical, and this shows just how different my two sides are. Like two very different people.

What I find interesting is that in cases of situs inversus with dextrocardia (i.e. all the organs are reversed, including the heart), a person can live indefinitely with no problems. It’s only in cases of situs inversus with levocardia (i.e. the heart is on the left but the other organs are reversed) or dextrocardia with the other organs on the normal side (called situs solitus) that you get into trouble, because the blood vessels connecting to the heart are malformed.

Your right colon is larger than your left (I think that’s what you meant by the going up/down comment- the colon is just pretty much a large tube, but it does taper off as it gets to the end). The Up/Down difference could be applied then to everything- your small interesting go in all sorts of weird directions! But physically- your right colon (the “up”) is larger than your left (the “down”).

Also, breasts tend to be asymmetrical as well. Each side responds differently to the amount of hormones in your body, and hence the asymmetry- same applies for males with gynecomastia (feminization of the chest/appearance of breasts due to excess estrogen), they too will have usually one larger than the other.

Also, your blood vessels aren’t the same throughout your body, you have some connections on your Left side that you don’t have on your right, and vice versa. Though with circulation you could almost say that almost EVERYONE has got some unique or different pattern going on in thier body- some functional change that will never really go noticed (unless it becomes a problem).
That’s why in Anatomy class, the professors had a saying:
“If you’ve seen one body, well then you’ve *one *body.”

Also, one Kidney tends to hang lower than the other/be slightly asymmetrical as well and not just randomly, but it was related to the testes thing in males. But I cannot recall the information right now, so I’ll leave that one unverifiable for now.

But yes, the body is filled with PLENTY of variations and asymmetry from size to shape to actual locations and organs that are only on one side vs. the other. And this isn’t even considering things like abnormalities in development, a whole nother topic of assymetries and craziness. Oh, and on the subject of situs inversus-
There’s also Transposition of the Great Vessels- this is a very serious congenital abnormality where your pulmonary arteries go from the left ventricle of the heart (rather than the right ventricles), and the Aorta arises out of the Right Ventricle (rather than the left ventricle). So in effect rather than one long closed off circulatory systems, you have two of them with them not really connected*
*This isn’t quite true there actually are connections in between the two systems as the lil’ guy would still have all your shunts still keeping you going as a fetus, but needless to say- life outside of the womb gets REAL serious real quick for the infant.

Would I be right in thinking that these kinds of asymmetries would typically be less pronounced in newborn infants than in adults? (and that some of them are acquired as a result of handedness and other behavioural stuff)?