« PrécédentContinuer »
the renal fascia by numerous connective tissue strands. These traverse the perinephric fat and undoubtedly assist in fixing the kidney in its place. The paranephric fat is present in greatest quantity behind the inferior part of the kidney, and in this position the layer of fibrous tissue, separating the two masses of fat and forming the posterior layer of the sheath of renal fascia, is usually well marked.
Fixation of the Kidney.—The kidney is not held in its place by any distinct ligaments, or special folds of peritoneum, but its fixation depends, to a large extent, on the pressure and counter-pressure which is exerted upon it by neighbouring structures, and on its connexions with the fascia renalis above described.
Posterior Relations and the Posterior Surface of the Kidney.--The muscles of the posterior abdominal wall on which the kidney rests are the psoas major, the
as a w iaphragm cinity pass
Fat behind colon
Fig. 981.—THE POSTERIOR RELATIONSHIPS OF THE KIDNEYS. The dotted lines indicate the contours of the
kidneys. The drawing is made from a model prepared by the late Professor Cunningham.
diaphragm the last rib
quadratus lumborum, the diaphragm and the tendon of the transversus abdominis. The abdominal surfaces of these muscles do not lie on the same plane, but slope towards one another, and thus the bed on which the kidney rests is not flat.
When but little fat is present, the posterior aspect of the kidney adapts itself to the inequalities of the surface against which it is placed, and so we may find on a kidney which has been carefully fixed and hardened before it has been disturbed, areas marked off for the different planes of these muscles. When such a kidney is in position, slight ridges or elevations separating these areas correspond to the angles along which the different muscular planes meet. These ridges can be observed in the hardened kidney, after its removal from the body, but usually they are not sharply defined, the angles between the muscular planes being very obtuse.
A kidney removed from the body after having been hardened in situ (Fig. 982)
w for ir
n area along the medial part of its posterior surface adapted to the spect of the psoas major muscle. This part of the posterior surface ially and slightly posteriorly. More laterally there is a larger area ts against the quadratus lumborum and looks more directly backwards. o areas are separated by a rounded ridge which fits into the angle be
muscles mentioned. Beyond the area in contact with the quadratus
is the thick lateral border of the kidney, which rests for the most e tendon of the transversus abdominis and on the diaphragm. ds the superior end of the kidney the posterior surface slopes somewhat and rests upon the diaphragm. Indeed the superior part of the kidney vhole, bent slightly forwards, following that part of the arch of the n on which it rests, and thus a narrow interval is left, in which the pleural sses down behind the superior end of the kidney (Fig. 981). This relation
-THE POSTERIOR ASPECT OP THE KIDNEYS. Same specimen as Fig. 981. The dotted lines mark out the areas in contact with the various muscles forming the posterior abdominal wall. a. Depression corresponding to the transverse process of the first lumbar vertebra. b. Depression corresponding to the transverse process of the second lumbar vertebra. c. Depression corresponding to the twelfth rib,
the pleural cavity to the kidney is of great importance in connexion with 1 operations performed through a lumbar incision. The portions of the gm to which the kidney is applied are the crus and the parts arising from trib and lumbo-costal arches. e posterior relationships of the kidney are well seen in Fig. 981. ddition to these surfaces, or "facets,” for the muscles with which it is in contact, the r aspect or lateral border of the kidney often shows a groove for the last rib, another for ral lumbo-costal arch, and two or three depressions for the tips of the transverse processes pper two or three lumbar vertebræ. In some cases also faint narrow grooves are to be : the nerves which pass downwards and laterally between the kidney and quadratus um-namely, the last thoracic nerve and the ilio-hypogastric and ilio-inguinal nerves. s probable that some at least of the depressions on the posterior aspect of the kidney are ed after death, and are caused by the weight of the other abdominal organs pressing the backwards against the more resisting structures of the abdominal wall, at a time when scles behind the kidney have become flaccid. When much fat is present the posterior of the kidney is more uniformly convex. ne lateral border in its middle and inferior part is rather a surface than a ', and looks for the most part directly backwards. It rests on the diaphragm on the anterior surface of the tendon of the transversus abdominis, to the lateral side of the quadratus lumborum muscle. The lateral border is narrowest above, and widest just below its middle point, corresponding to the greater thickness of the kidney at this level.
In many ways it would be more satisfactory to apply the term facies muscularis or muscular surface collectively to the areas above described as “posterior surface and “lateral border”; in like manner the term facies visceralis, or visceral surface, might be suitably applied to the so-called anterior surface of the organ. The edge separating the visceral from the muscular surface is the actual lateral edge or border of the kidney.
Anterior Relations and the Anterior Surface of the Kidney.-The anterior relations of the kidneys not only differ on the two sides of the body, but also many
Inferior vena cava
Superior mesenteric artery
Left crus of diaphragm
Medial lumbo costal arch
Lateral lumbo-costal arch
momenceme cadenum li cut of t cech in diff peritonel sney by cc
the ileum c kidney
In some - contact u er is, li 250 to th:
the left bid
Lateral cutaneous nerve of thigh
External iliac artery
Inferior mesenteric artery
TO THE MUSCLES OF THE POSTERIOR ABDOMINAL WALL.
Right Kidney.-A small area on the superior part of the anterior surface of the right kidney is in relation to the corresponding suprarenal gland (Fig. 983). The rest of the superior part of the anterior surface is in contact with the visceral surface of the liver, which is often hollowed out to form a fossa for the kidney, The suprarenal gland is bound to the kidney by connective tissue, while the part of the kidney in relation to the liver is, like the liver itself, covered by peritoneum, and thus the two organs, although closely applied, are really separated by a part of the general peritoneal cavity. Immediately anterior to the inferior end of the right kidney are usually found two parts of the alimentary canal-namely, the descending part of the duodenum and the right flexure of the colon, or the
... пар wh the at which a anterior a is a port and kidn ibe inferi be jejun
part of v
as agair anterior
ement of the transverse colon. The part of the kidney related to the 1 lies to the medial side of the area which touches the colon, but the exact f the kidney in contact with each of these two parts of intestine varies different subjects. Frequently the colon and the kidney are both covered neum where they are in contact, but the duodenum is bound down to the connective tissue. In addition to the structures mentioned, some portion um, or of the jejunum, is often found in contact with a small part of the ney near its inferior end. ne cases the peritoneal membrane does not cover the whole of the surface ; with the liver, and then the superior part of the hepatic area of the
like the anterior aspect of the suprarenal gland, bound by connective the "uncovered” area on the posterior aspect of the liver.
NTERIOR ASPECT OF THE KIDNEYS AND GREAT VESSELS. The drawing was made, before al of the organs, from a specimen in which the viscera had been hardened in situ. The dotted lines out the areas which were in contact with the various other abdominal viscera.
idney. The extreme superior and medial part of the anterior aspect of dney is united by connective tissue to the lower part of the left suprad, and the area immediately below this is in contact with the stomach increas. The pancreas, like the suprarenal gland, is bound down to the connective tissue, but the stomach is separated from the area with which position by a portion of the omental bursa. The area in actual contact tomach is a small somewhat triangular district situated above the level he pancreas is related to the kidney. The superior and lateral part of the pect of the kidney is related to the spleen, the two organs being separated on of the general peritoneal cavity, except along the area where spleen y are connected by the lieno-renal ligament. The anterior surface of r end of the left kidney is related, towards the medial side, to a part of m, and, towards the lateral side, to the left flexure of the colon or to a e descending portion of the colon. In most cases, however, the colon st the posterior abdominal wall to the lateral side rather than on the rface of the left kidney.
the vena porta. In the sixth week, these two rudiments meet and unite with one another, forming a long slender glandular mass which passes backwards within the dorsal mesogastrium (meso-duodenum), between the vertebral column and the greater curvature of the stomach. The pancreas, so formed, follows the changes which occur in the position of the stomach and of the dorsal mesogastrium. Consequently its free dorsal extremity comes to be directed to the left, while the right extremity or head is included within the hollow of the curve formed by the duodenum. At first, it possesses a dorsal mesentery, a part of the dorsal mesogastrium, but from the fifth month this disappear, coincidently with the rotation of the gland into the transverse axis of the body.
The lower part of the head, the body, and tail of the gland arise from the ventral element, and the upper part of the head arises from the dorsal bud.
The primary diverticula give off buds, lined with cylindrical epithelium, and these in turn give off other buds, and the process goes on until the mass of the gland is forned.
The islets of Langerhans are formed at a very early stage, from the entodermal lining cells of the branching diverticula which form the gland acini.