The urethra senses the sperm and fluid mixture. Then, at the height of sexual excitement, it sends signals to your spinal cord, which in turn sends signals to the muscles at the base of your penis. These contract powerfully and quickly, every 0.8 seconds. This forces the semen out of th...
Anatomy of a Penis The penis is a male sexual organ. The shaft is the longest part of it. The head or glans is at the end of the shaft. The opening at the tip of the head, where urine and semen come out, is called the meatus. ...
These long cervical ribs are ossified tendons of ventral neck muscles, presumably longus colli ventralis. We know they’re ossified tendons because of their bone histology (Klein et al. 2012), and we suspect that they’re longus colli ventralis because those tendons look the same in birds, jus...
1903, holotype FMNH PR 25107 from Dinosaur Quarry No. 13 near Grand Junction, Colorado, dating to the Kimmeridgian–Tithonian ages of the Late Jurassic, right dorsal rib “Rib A” in posterior view with proximal to the left.A1, the whole proximal half of the rib; a distal portion also ...
which is a spectacularly dumb piece of engineering and therefore great evidence against intelligent design creationism. It wasn’t the first time I’d heard of the RLN, of course. It’s one of the touchstones of both human anatomy and evolutionary biology; anatomy because of its clinical import...
satisfying for me, as is reading other people’s descriptions of weird anatomy. But I’m also in despair about how much basic descriptive work remains to be done, because the answers to so many questions are still over the horizon from us, and probably will be for the rest of my life....
(I say “primarily” because anatomy is never that simple and orthogonal: everything does two or three things, and apparently simple movements are generally the result of many different muscles working together.) In parts A and B of the figure, we showed relatively small ventral and lateral ...
Behold! The glory of the Lego Giraffatitan Move over, All Yesterdays: It’s time for #MikeTaylorAwesomeDinoArt, redux! Tutorial 46: how to write an abstract Tutorial 45: how to decide whether to do a higher degree in palaeontology The fate (so far) of my 50 submitted papers Rece...
couldn’t find on campus I could usually get through interlibrary loan. I spent a lot of time that fall standing at a photocopier, making copies of the classic sauropod monographs by Osborn, Hatcher, Gilmore, Janensch, and others, assembling the raw material to teach myself sauropod anatomy....
it could only have come from an elephant or an indricothere. Or a giant humanoid, I suppose, which is what the anatomy of the bone in the image most closely resembles. (It also appears to be foreshortened to make the distal end look bigger, or deliberately distorted to enhance the club...