CHAPTER XIV. SPASM OF THE SPHINCTER, NEURALGIA, WOUNDS, RECTAL ALIMENTATION. (Part 2)

condition of the organs the mea- surements are taken; Sappey, Yelpeau, and Legendre give five and a half cm. when the bladder is empty and eight when distended; Quain says four inches; Allingham from two to five or more. Oripps,* acting on the idea that the fold is not easily displaced downward by traction on the rectum, has experimented by filling the peritoneal cavity with plaster, and then thrusting a needle through the skin of the perineum till its point struck the plaster. In this way he has obtained an average measurement of two and a half inches when the bladder and rectum are both empty, and an additional inch when distended.' Muscular Coat. — In the fact that the muscular coat is arranged in two layers, an external longitudinal and an internal circular, the rectum resembles the other portions of the alimentary canal; but in the further arrangement of its fibres it resembles the oesophagus more closely than the intermediate portions. The fibres are spread out into two uniform 1 Cancer of the Rectum. London, 1880, p. 129. * The following authors give the following measurements: Malgaigne, male, 6-8 cm. ; females, 4-6 cm, Luschka, 6.5-8 cm. Hyrtl, 8 cm. ' Lisfranc and Sanson, 11 cm. Richet, males, 10.8 cm.; females, 16.2 cm. Blaudin, males, 8.1 cm.; females, 4.1 cm. Ferguson, males, 10.5 cm.; females, 15.4 cm. Esmarch: Die Krankheiten dee Mastdarms imd des Afters. Pitha u. Billroth: Chirurgie, p. 7. PBAOnCAL POINTS IN ANATOMY AND PHYSIOLOGY. 7 layers, and are not arranged in bands crossing each other in a basket net- work and leaving sacculi between the meshes. The longitudinal fibres are the direct continuation of the three longi- tudinal bands of the large intestine. Upon reaching the rectum, these blend into one continuous sheath which, however, is somewhat heavier on the anterior surface of the bowel than on any other. At the point of contact of the rectum with the bladder and prostate these fibres are in part reflected with the peritoneum on to the posterior wall of the latter and thus form a firm band of union between the two organs, as has been particularly described by Dr. Garson.* They have been named by him the recto-vesical fibres. The ending of the longitudinal fibres is worthy of note. According to Homer,' when they reach the lower margin of the internal sphincter a part of them turn upwards between it and the external sphincter and ascend for an inch or two in contact with the mucous ooat into which they are finally inserted; having, therefore, an obvious influence in caus- ing protrusion of the mucous membrane. In the lower fourth of their extent these fibres become weaker and less distinct, and some of them finally blend into elastic tendinous tissue which passes between the bun- dles of the external sphincter, and is inserted into the subcutaneous con- nective tissue of the anus. Others are inserted posteriorly by means of an elastic tendon about an inch long into the anterior sacro-coccygeal ligament — an arrangement pointed out by Luschka' as analogous to what is found in most mammalia, in whom a considerable number of the lon- gitudinal fibres are inserted into the base of the coccyx, giving a fixed point for the rectum in defecation. The circular layer is reinforced at certain points; notably at the in- ternal sphincter which is merely a collection of these fibres, and at a point higher up where they are again gathered into a bundle either partly or completely surrounding the bowel, known as the third sphincter. This muscle will be described more fully later. Suhnucous Coat. — The submucous tissue forming the bed upon which the mucous membrane rests is sufficiently lax to permit of consid- erable sliding of the mucous membrane on the muscular coat. In it the blood-vessels ramify, and from it perpendicular processes are given off which perforate both the internal and external muscular layers and are finally lost in the sheaths of the muscular fibres, or go entirely through the muscular layer and blend with the fibrous stroma of the surrounding ' The Arrangement and Distribution of the Muscular Fibres of the Rectum^ Paper read before the Brit. Med. Ass. Reported in Brit. Med. Jour., Sept. 6th, 1879. * A Treatise on Special and General Anatomy. YoL ii., p. 40, Philadelphia, 1836. ' Anat. des Menschen. Vol. ii., Part 2, p. 208. 8 DIBBA.BSB OF THB KBOTUM AITD AITDS. tatty tieene. Tliese processes from the submacone tissue, together with the lymph and blood-veBBels, serretobind the varions layers of the rectal wall together. ' See Fig, 2. Mucoui Membrane. — The mucons membrane of the rectum corresponds in its general characters with that of the other parts of the bowel, being modified, however, in certain partioalars to suit its location and func- tion. Its thickneaa is abont three-qnarters of a mm. ; it is redder and more vaacnlar than that of other parts of the large intestine; it glides freely on the tissue beneath; and is so ample as to be gathered into folds at rarionB points which are of considerable sorgical and anatomical interest At its point of nnion with the skin of the anus it is gathered into vertical folds which diminish when the bowel is distended, but. do not entirely disappear, and hence are not due solely to the contraction of the sphinc- ter. These vertical folds have received the name of columna recti, or columns of Morgagni; and Treitz states that they contain bands of mns- Fm. a.— Section at norma! rectal wall (Oripps). cnlar fibres running longitudinally and terminating above and below in elastic tissne. Kohlrausch* also describes a thin layer of longitndinal mnscalar fibres under the mucous membrane at this point and has named it the sustentator tunicis mucosm; but most anatomists, with Henle, have failed to find anything more than the stratum of muscular tissue common to the whole mucous coat, and known as the muscularis mucosm. Between the lower ends of the columncB recti little arches are stretched from one to the other, forming pouches of skin and mucous mem- brane. These are more developed in old people, and may retain small pieces of hardened fseces or foreign bodies in their cavities, and thus give rise to suppuration and abscess. The mucous membrane may for the purpose of study be divided into three separate layers, the muscular, glandular, and epithelial. Fig. 3. ' Grippe, op. cit., p. 38, ' Anat. u. PhTBiol, der Beok^iorgane, Leipzig, 1864. Bc^er alao eays they are Btrangthened hf muscular flbrea. Tisiti d'Anat,, 7. iv. Paris, 181S. PBACnCAI. POINTS IN ANATOUY AND PHYSIOLOGY. 9 The mnscnlar layer (musculai-is mucosis, sustentator tuniccs mucosis) is a layer of unstriped muscular tissue about 0.03 mm. thick, which is CTerywhere found in the deepest layer of the mucous membrane, extend- ing from the ceaophaguB to the rectum, but is more strongly developed in the region of the anus where it serves to hold the membrane in place and prevent prolapse. It consists of bundles running in some parts both lon- gitudinally and circularly, and in others in one direction only; and which send prolongations up between the glands to the villi. The glandular layer is about 0.07 mm. in thickness. It consists of a layer of Lieberknhn's follicles with an occasional solitary closed follicle below them, the situation of which is marked by a slight depression in the mucous membrane, and an absence of the tubular follicles at that point. The follicles are tubular depressions arranged vrith great regu- larity and set so closely together that the width of the intervening tissue Fis. S.— SactlOD of Uie rectal mucous menibraiie (Egmarch}. 1, FolllcleB of Lteberkuhu. 3. Muscular layer of mucouB membraae- B. Submucous coauoctive tlsaue aud TeaHels; with & Boli- tary ckned follicle, over which the tubular (oUIoles are wanduB- is, on the average, abont one-sixth the diameter of the follicle. The length of the tubes is fonr or five times their diameter, the respective measurements being: length, 0.35 mm.; diameter, 0.08 mm. These tubular depressions or follicles are lined with epithelial cells arranged with their bases resting ou the connective tissue and their apices free in the cavity of the follicle; and tlie cells of one follicle are directly contin- uous with those of the next hanging freely into the lumen of the bowel as they pass over from one depi-esaion into the next. The appearance of the cells is analogous to that of a bee's honeycomb, the intervening wall being common to two cells. The intertubular tissue consists of a fine trabecular network, the meshes of which are very long in the vertical direction running parallel to the follicle (Cripps). The follicles of Lieberkuhn arc simply inverted villi and answer the same purpose of absorption. There are good reasons for the substitution of follicles for villi in this part of the canal, the former being less subject 10 DISEASES OF THE SEOTUM AND ANUS. to injury from hardened faeces, and the fact of such enibstitution gathers great weight from the fact that in certain cases where an artificial anus has beexi established, the whole bowel below that point has been found in after-years covered with a growth of villi. ' Muscles of the Bectum and Anus, — The muscles which may properly be included in a description of the rectum and anus are the external and internal sphincters, the levator ani, ischio-coccygeus, retractor recti or recto-coccygeus, and the transversus perinei. External Sphincter. — The external sphincter muscle is a thin layer of voluntary fibres, about half an inch broad on each side of the anus, sur- rounding it in the form of an ellipse, and having a narrow pointed insertion anteriorly and posteriorly. It is situated immediately beneath the skin, and extends about two centimetres up the bowel where its upper limit may sometimes be seen by the white line already mentioned. It is divided into a superficial and deep portion. The superficial is inserted bq^th in front and behind into the subcutaneous cellular tissue. The deeper and thicker portion is inserted posteriorly by a narrow flat tendon into the posterior surface of the fourth coccygeal vertebra. Be- tween the tendon and the bone is a bursa about the size of a pea — ^bursa mucosa coccygea of Luschka. Anteriorly it is inserted into the central tendon of the perineum in common with the transversus perinei and bulbo-cavernosus, and in women with the sphincter vaginas. The action of the muscle is to close the anus and, under the control of the will, to antagonize the proper dilators of the anus, the levator ani and ischio- coccygeus, as well as the peristaltic action of the bowel and the contrac- tion of the diaphragm. The superficial band of fibres acts only in puckering the skin. The nerve-supply comes from the haemorrhoidal branch of the internal pudic, and the haemorrhoidal branch of the fourth sacral nerve; Internal Sphincter, — The internal sphincter is situated immediately above and partly within the deeper portion of the external sphincter; being separated from it by a layer of fatty connective tissue. Its thick- ness is about two lines; its vertical measurement from half an inch to an inch; and it is a direct continuation of the involuntary circular fibres of the bowel, growing thicker and stronger as it approaches the anus. It also is supplied by the haemorrhoidal branch of the internal pudic. Recto-coccygeus (Retractor recti, Trietz;' Tensor Fasciae Pelvis, Kohl- rausch). — This muscle consists of two flat lateral bands of unstriped fibres, each of which is about four mm. broad, which diverge at an acute angle from the anterior coccygeal ligament at the tip of the coccyx, and passing forward and downward, embrace the lower end of the rectum on * Specimen No. 1,288, Museum of College of Surgeons (Cripps). « Vierteljahrsschrift f. praktische Heilkunde. Praig, 1868, Bd. i., S. 124. Henle, Abbildtmg 2, 183. PBAOnOAL POINTS IN ANATOMY AND PHYBIOLOGY. 11 each side like a fork. It is located directly under that portion of the levator ani which forms the floor of the pelvis between the tip of the coccyx an^ the anus; and blends partly with the longitudinal muscular fibres of the rectum, and partly with the pelvic fascia surrounding its end. Its function is to hold the end of the rectum against the coccyx and to give it a fixed point in defecation. Levator Ani. — The levator ani and ischio-coccygeus muscles form a true diaphragm to the pelvis by giving an uninterrupted muscular and tendinous plane from the lower border of the pyriformis, behind, to the arch of the pubes in front. That part which is named ischio-coccygeus is usually described as a separate muscle, though in no way differing in function from the larger portion, and only distinguishable from it by its more tendinous structure. It is situated just in front of the sacro-sciatic ligaments, and arises by aponeurotic fibres from the sides and tip of the spine of the ischium, from the anterior surface of the lesser sacro-sciatic ligament, and often from the posterior part of the pelvic fascia« ♦It is in- serted, also by aponeurotic fibres, into the border of the coccyx and lower part of the border of the sacrum. Owing to its tendinous origin and in- sertion, the greater part of the muscle is composed of aponeurotic fibres. It is in relation superiorly, by its concave surface, with the rectum; inferiorly, by its convex surface, with the sacro-sciatic ligaments and the gluteus maximus; posteriorly, its border is in contact with the lower border of the pyriformis; and anteriorly, it is directly continuous with the fibres of the levator ani. Its action is to draw the coccyx to its own side, or, when both muscles act together, to fix that bone and prevent its being thrown backward in defecation. It probably has no such action as would justify the name of levator coccygis, given it by Morgagni. Its nerve-supply is from the anterior branch of the fourth sacral nerve. The levator ani proper, which constitutes the remaining portion of the pelvic diaphragm, is in its general shape an inverted cone, support- ing the pelvic contents in its cavity and allowing the rectum and prostate to pass through its apex. Considering each lateral half of the muscle apart, we find it made up of a delicate layer of muscular fibres forming A thin, curved, and quadrilateral sheet, broader behind than in front. Its upper border is stretched across the pelvis from the pubes to the spine of the ischium, arising from both these bony points and from the tendinous line of union of the pelvic with the obturator fascia, which runs antero-posteriorly between them. Its attachment to the pubic bone is at a point on its inner surface, near the middle of the descending ramus and a little to one side of the symphysis. This attachment will be found to vary somewhat in different dissections, being sometimes a little higher or a little lower on the bone, and sometimes on the cartilage between the bones. The muscular fibres may also be traced at times up- ward into the pelvic fascia above its junction with the obturator. From this extensive though delicate and in great part membranous 12 DI8BA8E8 OF THE BEOTUM AND ANUS. origin^ the fibres proceed downwards and inwards toward the median line. Those most anterior unite with those of the opposite side beneath the neck of the bladder, the prostate, and the adjacent portion of the urethra. These fibres are concealed by the pubo-prostatic ligament or anterior fold of the recto- vesical fascia, from which they also sometimes take origin in part. They are in relation, in front, with the posterior surface of the triangular ligament. This portion is sometimes separated from the main body of the muscle by a cellular interval, similar to those often found in other parts of this thin muscular sheet. The fibres which arise from the tip of the spine of the ischium are inserted into the side of the tip of the coccyx; while the fibres immedi- ately in front of these (precoccygeal) unite with those of the opposite side in the median line and form a raphe which extends from the point of the coccyx to the posterior border of the sphincter and thus complete the floor of the pelvis. The fibres which arise indirectly from the upper part of the obturator foramen and from the brim of the pelvis by mean^ of the pelvic fascia, pass downward and inward, forming a curve with its concavity upwards, and may be divided into vesical and anal. The vesical pass into the sides of the bladder. The anal fibres in part pass backward and meet behind the bowel and in part blend with those of the external sphincter at its upper border, there being no distinct line of separation between the two muscles. The relations of the levator ani are of great surgical importance. Superiorly its surface is covered by the superior pelvic fascia which sepa- rates it from the peritoneum and pelvic organs. Its inferior surface is sepa- rated from the obturator internus muscle by the obturator fascia, and be- neath this is the ischio-rectal fossa. The posterior part of the muscle is in relation with the gluteus maximus. The actions of this muscle are various. First, it acts as a support to the pelvic organs, and antagonizes the diaphragm and abdominal muscles wheti they act upon the abdominal contents. Again, it prevents the rec- tum from being protruded, and raises the anus and opens it; being in this respect the direct antagonist of sphincter. By inclosing the neck of the bladder the muscle acts upon it also, and in the act of defecation when the muscle is contracted to open the anus, the neck of the bladder is pressed upon and the urethra closed. In this way is explained the well-known difficulty of passing urine and fseces