36 
DR. PETTIGREW ON THE MUSCULAR ARRANGEMENTS 
the catheter is being passed through the prostatic portion of the urethra, and which is 
not felt by the female, is owing probably not so much to the supposed heightened 
sensibility of the parts as to mechanical obstruction and entanglement. That the pain 
in question is referable to the region of the verumontanum and not to the trigone, as is 
commonly believed, seems certain from a fact first stated by Guthrie*, that in the 
healthy bladder even when moderately distended the triangular space descends so as to be 
beyond the reach of the catheter. The extreme sensitiveness of the trigone in disease, 
or when irritated by the presence of a stone, is moreover no proof of its increased 
sensibility in the normal condition of the parts. If the trigone, as Sabatier, Bell, and 
others affirm, be so delicately sensitive, it is difficult to understand how the urine, which 
naturally collects in the neck of the bladder, is not expelled almost as soon as it is 
received. Bell and Guthrie lay considerable emphasis upon the unusually large 
supply of nerves to this part, but repeated and very careful dissections of the nerves 
of the bladder, not only in man but in the ox, sheep, monkey, and other animals, 
induce me to dissent from their views. The supply to the trigone in no way exceeds 
that to the parts surrounding the neck of the bladder generally. The nerves and 
likewise the blood-vessels are more numerous at the neck and fundus than they are 
towards the apex and higher up, but the distribution is uniform, and consists of a 
complete network, which extends itself over the external and internal surfaces and 
within the walls. The network, I may observe, is remarkable for the immense number 
of ganglia it everywhere displays, these in some instances, particularly on the sides 
of the bladder, being exceedingly large. In the ox I have found them of the size 
of a small millet seed, and in man and in the monkey they are correspondingly 
developed. 
Muscles of Bell. — The muscular fibres which run between the orifices of the ureters 
and urethra, and which form the lateral boundaries of the trigone, had undue prominence 
assigned them by BELLf, who described them as separate structures under the title of 
muscles of the ureters. These muscles, he says, are inserted by tendons into the middle 
lobe of the prostate, and their function is to preserve the due obliquity of the orifices 
of the ureters. They have, however, neither the insertion nor function indicated. 
They are continued into the verumontanum and urethra, and apart from the other fibres 
of the trigone have no existence. The obliquity of the ureters, moreover, as has been 
shown, is primarily secured by the fibres of the ureters being continued into each 
other within the bladder. Sir Charles seems to have been misled by dissecting 
hypertrophied bladders from without, and by supposing that the coat of the bladder 
which contracts is on the outside of the oblique passages of the ureters, an arrangement 
necessitating, as he thought, some counteracting power on the inside to draw down the 
* On the Anatomy and Diseases of the Urinary Organs and Sexual Organs, By G. J. Guthbie, F.R.S. 3rd 
edit. Lond. 1843, p. 6. 
f “ Account of the Muscles of the Ureters and their effects on the irritable states of the Bladder. By Chaeles 
Bell, Esq.” Med. Chir. Trans, yol. iii. 1812. 
