The surgical anatomy of the principal regions of the human body / by Thomas Morton and William Cadge.

  • Morton, Thomas, 1813-1849.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: The surgical anatomy of the principal regions of the human body / by Thomas Morton and William Cadge. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    During the removal of this fat, some small arteries which run in its substance should be preserved : these are the external or inferior hsemorrhoidal arteries, branches from the internal pudic vessels, and given off from these as they are running along under cover of the tuberosities of the ischia. They are distri- buted to the superficial structures around the inferior extremity of the alimentary canal. These little vessels are worthy of attention, as they are frequently divided in the operations of lithotomy and of fistulse in ano, &c. and may sometimes furnish a considerable quantity of blood ; sufficient indeed to render the application of a compress or a ligature necessary, to prevent the continuance of the bleeding. When all the fat has been removed, a large excavated hollow remains on each side of the anus ; these have been named by M. Velpeau the ischio-rectal fossce. The figure of each of these spaces is triangular, the base being formed by the skin, and the apex or summit by the angle where the fibres of the levator ani separate from the obturator fascia. The internal wall is very oblique, and is formed by the fibres of the levator ani; the external one on the other hand is nearly perpendicular, and is formed by the obturator fascia and the tuberosity of the ischium.* The depth of the cavity increases towards the ex- ternal wall, where it may be estimated at nearly two inches. If the subject has been injected, by placing the finger against the external wall of the cavity, about an inch above the edge of the tuberosity of the ischium, the internal pudic artery can be * The obturator fascia is a thick and strong membrane, which binds down the obturator internus muscle to the internal surface of that part of the OS innominatum, and to the ligament of the thyroid foramen, from which its fibres take their origin. The fascia is attached superiorly to the margins of the thyroid foramen, posteriorly to the spinous process of the ischium, and inferiorly to the falciform process of the great sacro-sciatic ligament, and the rami of the ischium and os pubis. Relations—externally with the obtu- rator interuus muscle ; internally with the pelvic fascia, part of the origin of the levator ani, and the adipose substance which fills the ischio-rectal space. The internal pudic vessels and nerve, as they pass from the smaller sciatic foramen, by which they re-entered the pelvis, to their termination in the branches which they furnish to the bulb, corpus cavernosum, and dorsum of the penis, are inclosed in a sheath, which is formed by the division of the fascia into two lamellse at this point. The inferior haemorrhoidal and super- ficialis permai arteries pierce this fascia immediately after their origin from the trunk.