1Anatomy of the Genitourinary TractWord文档下载推荐.docx

1、INTRODUCTION Urology deals with diseases and disorders of the male genitourinary tract and the female urinary tract. Surgical diseases of the adrenal gland are also included. These systems are illustrated in Figures 1-1 and 1-2. ADRENALS Gross Appearance A. Anatomy Each kidney is capped by an adrena

2、l gland, and both organs are enclosed within Gerotas （perirenal） fascia. Each adrenal weighs about 5 g. The right adrenal is triangular in shape; the left is more rounded and crescentic. Each gland is composed of a cortex, chiefly influenced by the pituitary gland, and a medulla derived from chromaf

3、fin tissue. B. Relations Figure 1-2 shows the relation of the adrenals to other organs. The right adrenal lies between the liver and the vena cava. The left adrenal lies close to the aorta and is covered on its lower surface by the pancreas; superiorly and laterally, it is related to the spleen. His

4、tology The adrenal cortex is composed of 3 distinct layers: the outer zona glomerulosa, the middle zona fasciculata, and the inner zona reticularis. The medulla lies centrally and is made up of polyhedral cells containing eosinophilic granular cytoplasm. These chromaffin cells are accompanied by gan

5、glion and small round cells. Blood Supply A. Arterial Each adrenal receives 3 arteries: one from the inferior phrenic artery, one from the aorta, and one from the renal artery. B. Venous Blood from the right adrenal is drained by a very short vein that empties into the vena cava; the left adrenal ve

6、in terminates in the left renal vein. Lymphatics The lymphatic vessels accompany the suprarenal vein and drain into the lumbar lymph nodes. KIDNEYS The kidneys lie along the borders of the psoas muscles and are therefore obliquely placed. The position of the liver causes the right kidney to be lower

7、 than the left （Figures 1-2 and 1-3）. The adult kidney weighs about 150 g. The kidneys are supported by the perirenal fat （which is enclosed in the perirenal fascia）, the renal vascular pedicle, abdominal muscle tone, and the general bulk of the abdominal viscera. Variations in these factors permit

8、variations in the degree of renal mobility. The average descent on inspiration or on assuming the upright position is 4-5 cm. Lack of mobility suggests abnormal fixation （eg, perinephritis）, but extreme mobility is not necessarily pathologic. On longitudinal section （Figure 1-4）, the kidney is seen

9、to be made up of an outer cortex, a central medulla, and the internal calices and pelvis. The cortex is homogeneous in appearance. Portions of it project toward the pelvis between the papillae and fornices and are called the columns of Bertin. The medulla consists of numerous pyramids formed by the

10、converging collecting renal tubules, which drain into the minor calices at the tip of the papillae. Figures 1-2 and 1-3 show the relations of the kidneys to adjacent organs and structures. Their intimacy with intraperitoneal organs and the autonomic innervation they share with these organs explain,

11、in part, some of the gastrointestinal symptoms that accompany genitourinary disease. A. Nephron The functioning unit of the kidney is the nephron, which is composed of a tubule that has both secretory and excretory functions （Figure 1-4）. The secretory portion is contained largely within the cortex

12、and consists of a renal corpuscle and the secretory part of the renal tubule. The excretory portion of this duct lies in the medulla. The renal corpuscle is composed of the vascular glomerulus, which projects into Bowmans capsule, which, in turn, is continuous with the epithelium of the proximal con

13、voluted tubule. The secretory portion of the renal tubule is made up of the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule. The excretory portion of the nephron is the collecting tubule, which is continuous with the distal end of the ascending limb of the convoluted

14、tubule. It empties its contents through the tip （papilla） of a pyramid into a minor calyx. B. Supporting Tissue The renal stroma is composed of loose connective tissue and contains blood vessels, capillaries, nerves, and lymphatics. Blood Supply （Figures 1-2, 1-4, and 1-5） Usually there is one renal

15、 artery, a branch of the aorta, that enters the hilum of the kidney between the pelvis, which normally lies posteriorly, and the renal vein. It may branch before it reaches the kidney, and 2 or more separate arteries may be noted. In duplication of the pelvis and ureter, it is usual for each renal segment to have its own arterial supply. The renal artery divides into anterior and posterior branches. The posterior branch supplies the mid segment of the posterior surface. The anterior branch supplies both upper and lower poles as well as the entire anterior sur