醫(yī)科大學教材翻譯《系統(tǒng)解剖學》 第四章 泌尿系統(tǒng) 泌尿系統(tǒng)由腎、輸尿管、膀胱及尿道四部分組成。它的主要功能是排出機體內溶于水的代謝產物。機體在新陳代謝中所產生的廢物如尿素、尿酸和多余的水分等，由循環(huán)系統(tǒng)送至腎，在腎內形成尿液，再經排尿管道排出體外。尿的質和量經常隨機體內環(huán)境的改變而發(fā)生一定的變化，對保持內環(huán)境的相對穩(wěn)定和電解質的平衡起著重要的作用。如腎功能發(fā)生障礙，代謝產物蓄積于體內，改變了內環(huán)境的理化性質，則產生相應的病變，嚴重時可出現(xiàn)尿毒癥，甚至危及生命。 Chapter IV Urinary System The urinary system consists of kidney, ureter, bladder and urethra. Its main function is to expel water-soluble metabolites from the body. Wastes such as urea, uric acid and excess water produced by the body in metabolism are sent to the kidney by the circulatory system, and urine is formed in the kidney, and then discharged from the body through the urination duct. The quality and quantity of urine often change with the internal environment, which plays an important role in maintaining the relative stability of internal environment and electrolyte balance. If renal function is impaired and metabolites accumulate in the body, which changes the physical and chemical properties of the internal environment, corresponding pathological changes will occur, and uremia may occur in severe cases, which may even be life-threatening. 第一節(jié) 腎 一、腎的形態(tài) 腎是成對的實質性器官，形似蠶豆，左右各一，在脊柱的兩側貼于腹后壁。新鮮腎呈紅褐色，腎的大小因人而異。正常成年男性平均長約10cm，寬5cm，厚4cm，平均重量為134~148g。一般女性腎略小于男性。腎可分上、下端，內、外側緣和前、后面。腎上端寬而薄，下端窄而厚。前面較凸，朝向前外側；后面較平，貼靠腹后壁。外側緣凸隆；內側緣中部凹陷，是腎的血管、淋巴管、神經和腎盂出入的部位，稱為腎門。腎門長約2~3cm，寬1.4~2.5cm。出入腎門的結構合稱腎蒂。腎蒂主要結構的排列關系：由前向后依次為腎靜脈、腎動脈和腎盂；從上向下依次為腎動脈、腎靜脈和腎盂。因下腔靜脈位于中線右側，致使右側腎蒂較左側的為短，在腎手術時可造成一定的困難。腎門向腎內續(xù)于一個較大的腔，稱為腎竇，由周圍的腎實質圍成，內含腎動脈、腎靜脈的主要分支和屬支、腎小盞、腎大盞、腎盂和脂肪組織等。 Section 1 Kidney First, Morphology of the kidney The kidneys are paired parenchymal organs, shaped like broad beans, one on the left and one on the right, and attached to the posterior abdominal wall on both sides of the spine. The fresh kidney is reddish brown, and the size of the kidney varies from person to person. For average adult male, it is about 10cm long, 5cm wide and 4cm thick, and the average weight is 134~148g g. Generally, women's kidneys are slightly smaller than those of men. Kidney can be divided into upper and lower ends, medial and lateral edges, and anterior and posterior surfaces. The upper end of the kidney is wide and thin, and the lower end is narrow and thick. The anterior surface is convex, facing the lateral front; The posterior surface is flat and clings to the posterior abdominal wall.?The lateral margin is protruding; The middle part of the medial margin is depressed, which is the place where the blood vessels, lymphatic vessels, nerves and renal pelvis of the kidney come in and out, and is called the renal hilum. Renal hilum is about 2~3cm long and 1.4~2.5cm wide. The structure entering and leaving the renal hilum is called renal pedicle. The arrangement of the main structures of renal pedicle from front to back: renal vein, renal artery and renal pelvis; From top to bottom: renal artery, renal vein and renal pelvis. Because the inferior vena cava is located on the right side of the midline, the right renal pedicle is shorter than the left one, which may cause some difficulties in renal surgery. The hilum of the kidney continues into the kidney in a larger cavity called renal sinus, which is surrounded by the surrounding renal parenchyma, and contains the main branches and affiliated branches of renal artery and renal vein, renal calyx minor, renal calyx major, renal pelvis and adipose tissue. 二、腎的構造 在腎的額狀切面上，可見腎實質分為皮質和髓質兩部分。腎皮質主要位于淺層，富含血管，新鮮標本為紅褐色，肉眼可見密布的細小顆粒(相當腎小體)。腎髓質位于腎實質的深部，色淡，由許多小的管道組成，它們形成15~20個錐形的腎錐體，錐體的基底朝向皮質；尖端圓鈍，朝向腎竇，稱為腎乳頭。有時2~3個腎錐體合成一個腎乳頭。乳頭的頂端有許多小孔，稱為乳頭孔。腎形成的尿液由乳頭孔流入腎小盞內。淺層的腎皮質伸入腎錐體之間的部分稱為腎柱。 Second, the structure of the kidney On the frontal section of the kidney, the renal parenchyma can be divided into cortex and medulla. The renal cortex is mainly located in the superficial layer, rich in blood vessels, and the fresh specimen is reddish brown, with dense fine particles visible to the naked eye. (equivalent to renal corpuscles). The renal medulla is located in the deep part of renal parenchyma, and it is pale in color. It is composed of many small tubes, which form 15~20 cone-shaped renal pyramids, and the base of the cone faces the cortex. The tip is round and blunt, facing the renal sinus, which is called renal papilla. Sometimes 2~3 renal pyramids compose one renal papilla. There are many small holes at the top of the papilla, which are called papillary foramina. The urine formed by the kidney flows into minor renal calices from the papillary foramina. The part of the superficial renal cortex extending between renal pyramids is called renal column. 腎竇內約有7~8個呈漏斗狀的腎小盞，小盞的邊緣附著于腎乳頭基部，包繞腎乳頭，以承接排出的尿液。2~3個腎小盞合成一個腎大盞，腎大盞約2~3個，再集合成一個前后扁平、約呈漏斗狀的腎盂。腎盂出腎門后，向下彎行，逐漸變細移行為輸尿管。腎盂的形態(tài)有變異，以二支型最多，占74%；次為三支型，占12%；較膨大的為壺腹型，占6%；介于分支型與壺腹型之間的形狀較扁窄，為中間型，占8%。 There are about 7~8 funnel-shaped renal calyces in the renal sinus, and the edge of the calyces is attached to the base of the renal papilla, which surrounds the renal papilla to accept the urine discharged. 2~3 minor renal calyces are combined into a major renal calyx, and about 2~3 major renal calyces then assembled into a flat, funnel-shaped renal pelvis. After the renal pelvis leaves the renal hilum, it bends downward and gradually tapers to the ureter. The shape of renal pelvis is varied, most of them are of bifurcation type, accounting for 74%; The second type is three branches, accounting for 12%; The bulging one is of ampulla type, accounting for 6%; The shape between the branching type and the ampulla type is flat and narrow, and it is the middle type, accounting for 8%. 三、腎的位置和被膜 (一)腎的位置 正常成年人的腎位于腹膜后間隙內，脊柱的兩側，貼靠腹后壁的上部。腎的長軸向外下傾斜，男性腎的上端距正中線的距離：左側為4.2cm，右側為4.0cm；下端距正中線的距離：左側為5.5cm，右側為5.7cm。腎的高度，左腎上端平第12胸椎上緣，下端平第3腰椎上緣；右腎上端平第12胸椎下緣；下端平第3腰椎下緣，即右腎低于左腎。第12肋斜越左腎后面的中部，右腎后面的上部。腎門約平第1腰椎平面，距正中線約5cm。在豎脊肌的外側緣與第12肋之間的部位稱為腎區(qū)(脊肋角)。在某些腎疾病患者，叩擊或觸壓此區(qū)可引起疼痛。正常時腎的位置可隨呼吸和體位而上下移動幅度約為2~3cm。腎的位置一般女性低于男性，兒童低于成人，新生兒的則更低，其至可達髂嵴附近。 Third, the location and capsules of kidney (One) the location of kidney The kidneys of normal adults are located in the retroperitoneal space, on both sides of the spine, and close to the upper part of the abdominal posterior wall. The long axis of the kidney inclines outwards and downwards, and the distance from the upper end of the male kidney to the midline is 4.2cm on the left and 4.0cm on the right; Distance from the lower end to the center line is 5.5cm on the left and 5.7cm on the right. The height of the kidney, the upper end of the left kidney is level with the upper edge of the 12th thoracic vertebra, and the lower end is level? with the upper edge of the 3rd lumbar vertebra; The upper end of the right kidney is flat with the lower edge of the 12th thoracic vertebra; The lower end is flat to the lower edge of the third lumbar vertebra, that is, the right kidney is lower than the left kidney. The 12th rib obliquely crosses the middle part of the posterior surface of the left kidney and the upper part of the right one. The hilum of the kidney is approximately level with the plane of the first lumbar vertebra, about 5cm away from the midline. The part between the lateral edge of erector spinae and the 12th rib is called the renal region (the spine rib angle). In some patients with renal diseases, tapping or touching this area can cause pain. Under normal circumstances, the position of the kidney can move up and down with breathing and posture by about 2~3cm. The position of the kidney is generally lower in women than in men, lower in children than in adults, and even lower in newborns, which reaches to the vicinity of iliac crest. 腎的毗鄰：腎后面上1/3借膈與肋膈隱窩相鄰，腎手術時應注意勿傷胸膜。腎后下2/3與腰大肌、腰方肌和腹橫肌相鄰。腎前面的鄰接左、右不同：右腎鄰十二指腸、肝右葉和結腸右曲；左腎鄰胃、胰、空腸、脾和結腸左曲。兩腎上端均緊鄰腎上腺。 Adjacency of kidney: the upper 1/3 of renal posterior surface is adjacent to the costal phrenic recess through the diaphragm, so care should be taken not to hurt the pleura during kidney surgery. The posterior lower 2/3 of the kidney is adjacent to psoas major, quadratus lumborum and transverse abdominis muscles. The left and right adjacencies of renal anterior surface are different: the right kidney is adjacent to the duodenum, the right lobe of the liver and the right curvature of the colon; The left kidney is adjacent to the stomach, pancreas, jejunum, spleen and colon. The upper ends of both kidneys are close adjacent to the adrenal glands. (2) The capsules of kidney The surface of the kidney is surrounded by three layers of membranes from the interior to the exterior. 1. Fibrous capsule: a thin layer of dense and tough connective tissue membrane attached to the surface of renal parenchyma, containing a small amount of elastic fibers. Under normal circumstances, it is easy to separate from renal parenchyma, and under pathological conditions, it adheres to renal parenchyma and is not easy to peel off. This membrane should be sutured when the kidney is ruptured or partially removed. 2. Adipose capsule: It is the fat tissue around the fibrous capsule, with more fat at the edge of the kidney and continuous with the fat tissue in the renal sinus through the renal hilum. Adipose capsule plays a protective role of elastic pad on kidney. 3. Renal fascia: located at the periphery of the adipose capsule, developed from extraperitoneal tissue. The renal fascia is divided into anterior and posterior layers, which surround the kidney and adrenal gland. Above and outside the kidney, the two layers merge with each other. The two layers below the kidney are separated, and the ureter passes between them. On the inner side of the kidney, the anterior layer extends to the front of the abdominal aorta and inferior vena cava and continues with the anterior layer of the opposite renal fascia, and the posterior layer is merged with the psoas major fascia. The renal fascia sends out many small bundles of connective tissue to the deep surface, which pass through the adipose capsule and connect to the fibrous capsule, thus fixing the kidney. (二)腎的被膜 腎的表面自內向外有三層被膜包繞。 1.纖維囊：為貼附于腎實質表面的薄層致密堅韌的結締組織膜，內含少量彈力纖維。正常情況下，易與腎實質分離，在病理情況下，則與腎實質發(fā)生粘連，不易剝離。腎破裂或腎部分切除時，需縫合此膜。 2.脂肪囊：為纖維囊外周的脂肪組織，在腎的邊緣處脂肪較多，并通過腎門與腎竇內的脂肪組織相連續(xù)。脂肪囊對腎起彈性墊的保護作用。 3.腎筋膜：位于脂肪囊的外周，由腹膜外組織發(fā)育而來。腎筋膜分前、后兩層，包繞腎和腎上腺。在腎的上方和外側，兩層互相融合。在腎的下方兩層分離，其間有輸尿管通過。在腎的內側，前層延至腹主動脈與下腔靜脈的前面與對側腎筋膜前層相續(xù)連，后層與腰大肌筋膜融合。腎筋膜向深面發(fā)出許多結締組織小束，穿過脂肪囊連于纖維囊，對腎起固定作用。 腎的正常位置靠多種因素來維持，腎被膜、腎血管、腎的毗鄰器官、腹內壓以及腹膜等對腎均起固定作用。腎的固定裝置不健全時，可形成腎下垂或游走腎。 The normal position of kidney is maintained by many factors, such as renal capsule, renal blood vessels, adjacent organs of kidney, intra-abdominal pressure and peritoneum. When the fixation device of kidney is not perfect, it can form nephroptosis or wandering kidney. 四、腎段的概念和腎的異常 (一)腎段的概念 腎動脈在腎實質的分支按一定的節(jié)段分布。一個段動脈分布一定區(qū)域的腎組織。一個腎段動脈所分布的這部分腎組織稱為一個腎段。每個腎分為5個腎段：上段、上前段、下前段、下段和后段。各段動脈分支之間無吻合，一個段動脈出現(xiàn)血流障礙時，它所供應的腎段即可出現(xiàn)壞死。了解腎段，對腎疾病的定位和部分切除術有實用意義。 Fourth, the concept of renal segment and renal abnormality (One) the concept of renal segment The branches of renal artery in renal parenchyma are distributed in certain segments. A segmental artery distributes renal tissue in a certain area. This part of renal tissue where a segmental renal artery is distributed is called a renal segment. Each kidney is divided into five renal segments: upper segment, upper anterior segment, lower anterior segment, lower segment and posterior segment. There is no anastomosis between the branches of each segment artery. When a segment artery has blood flow disorder, the renal segment it supplies can be necrotic. Understanding the renal segment is of practical significance for the localization and partial nephrectomy of renal diseases. (二)腎的異常 腎在發(fā)育過程中，可出現(xiàn)形態(tài)、位置、數(shù)目等方面的異?；蚧?。常見的有:①馬蹄腎:左右兩腎下端互相連接形成馬蹄鐵形;2多囊腎:由于胚胎時腎小管與集合管不相通連，液體貯留于腎小管內，致使膨大成囊狀;③雙腎盂及雙輸尿管:如輸尿管芽末端分二支，則形成雙腎盂;④單腎:一側腎缺如或發(fā)育不全稱為單腎;⑤低位腎:于胚胎早期，腎原位于盆部，隨著胎兒的發(fā)育逐漸上升至腰部，若發(fā)育停滯，即可成低位腎，可位于髂窩或小骨盆腔內。 (Two) Renal abnormalities During the development of kidney, there may be abnormalities or deformities in shape, position and number. Common ones are: ① horseshoe kidney: the lower ends of the left and right kidneys are connected with each other to form horseshoe shape; Polycystic kidney: because the renal tubule is not connected with the collecting duct in the embryo, the liquid is stored in the renal tubule, which causes it to expand into a cyst; (3) Double renal pelvis and double ureters: If the ureter bud ends in two branches, double renal pelvis will be formed; ④ Single kidney: the absence or hypoplasia of one kidney is called single kidney; ⑤ Low kidney: In the early embryo, the kidney is located in the pelvis, and gradually rises to the waist with the development of the fetus. If the development is stagnant, it can become a low kidney, which can be located in the iliac fossa or small pelvic cavity. 第二節(jié) 輸尿管 Section Two: Ureter 輸尿管為細長的肌性管道，左右各一，長度平均男性為26.5cm，女性為25.9cm，管徑約為0.5~0.7cm。起自腎盂下端，終于膀胱。輸尿管有較厚的平滑肌層，可作節(jié)律性的蠕動，使尿液不斷地流入膀胱。如因結石阻塞而過度擴張，可產生痙攣性收縮而產生疼痛即腎絞痛。 The ureter is a slender muscular tube, one on the left and one on the right, with an average length of 26.5cm for men and 25.9cm for women, and a diameter of about 0.5~0.7cm. It originates from the lower end of the renal pelvis and ends in the bladder. The ureter has a thick smooth muscle layer, which can be used for rhythmic peristalsis, so that urine can continuously flow into the bladder. If it is excessively dilated due to stone obstruction, it can produce spasmodic contraction and pain, that is, renal colic. 輸尿管的行徑與分段：輸尿管按行徑可分為腹段、盆段和壁內段。輸尿管自腎盂下端起始后，在腹后壁腹膜的深面，沿腰大肌前面下降。達小骨盆入口處，左、右輸尿管分別越過左髂總動脈末端和右髂外動脈起始部的前面，此段稱為腹段。 Pathway and segmentation of ureter: Ureter can be divided into abdominal segment, pelvic segment and intramural segment according to its pathway. After the ureter starts from the lower end of the renal pelvis, it descends along the front of psoas major in the interior side of the peritoneum of the abdominal posterior wall. At the entrance of the small pelvis, the left and right ureters respectively cross the end of the left common iliac artery and the front of the beginning of the right external iliac artery, and is called abdominal segment. 從髂血管入盆腔，先沿盆側壁向下向后，越過盆壁血管神經的表面，約在坐骨棘水平轉向前內側穿入膀胱底的外上角，這一段稱為盆段。在女性，輸尿管經過子宮頸的外側，陰道穹側部的上方，距子宮頸約1.5~2cm，此處有子宮動脈橫過其前上方；在男性有輸精管越過輸尿管下端的前方。 From iliac vessels into the pelvic cavity, it first goes down and backward along the pelvic side wall, crosses the surface of the vessels and nerves in the pelvic wall, and turn to the anterior medial side at the level of sciatic spine and then penetrates into the outer upper corner of the bladder bottom. This section is called pelvic segment. In women, the ureter passes through the lateral side of the cervix, above the lateral part of the vaginal vault, about 1.5~2cm away from the cervix, where the uterine artery crosses the anterior upper part; In men, the vas deferens crosses the front of the lower end of ureter. 輸尿管自膀胱底的外上角，向內下斜穿膀胱壁，于輸尿管口開口于膀胱，此部稱為壁內段，長約1.5~2.0cm。當膀胱充盈時，膀胱內壓增高，將壁內段壓扁，管腔閉合，可防止膀胱中的尿液返流人輸尿管。由于輸尿管的蠕動尿液仍可不斷地進入膀胱。若壁內段過短或其周圍的肌組織發(fā)育不良時，也可出現(xiàn)尿返流現(xiàn)象。 The ureter passes through the bladder wall from the outer upper corner of the bladder bottom obliquely inward and downward, and opens in the bladder at the orifice of the ureter, which is called the intramural segment and is about 1.5~2.0cm long. When the bladder is full, the internal pressure of the bladder increases, flattening the inner wall and closing the lumen, which can prevent the urine in the bladder from flowing back to the ureter. Urine can still enter the bladder continuously due to the peristalsis of ureter. If the intramural segment is too short or the muscle tissue around it is underdeveloped, urine reflux can also occur. 輸尿管的狹窄部：①腎盂與輸尿管移行處；②與髂血管交叉處；③壁內段。這些狹窄處常是輸尿管結石滯留的部位。 The strictures of ureter: ① the transition between renal pelvis and ureter; ② Intersection with iliac vessels; ③ intramural segment. These strictures are often the sites where ureteral stones remain. 第三節(jié) 膀胱 膀胱是儲存尿液的囊狀肌性器官，其形狀、大小和位置均隨尿液充盈的程度而變化。膀胱的平均容量，一般正常成年人約為300~500ml，最大容量可達800ml。新生兒的膀胱容量約為成人的1/10。老年人由于膀胱肌肉的緊張力降低，容積增大。女性膀胱容量較男性為小。 Section Three: Bladder Bladder is a cystoid muscular organ for storing urine, and its shape, size and position change with the degree of urine filling. The average volume of bladder is about 300~500ml for normal adults, and the maximum volume can reach 800ml. The bladder capacity of newborns is about 1/10 of that of adults. Old people's bladder has increased volume due to decreased muscular tension. Female bladder capacity is smaller than that of male. 一、膀胱的形態(tài) 膀胱空虛時呈三棱錐體形。頂端朝向前上，稱膀胱尖。底部呈三角形，朝向后下，稱膀胱底。尖與底之間的大部分稱膀胱體。膀胱的下部有尿道內口，與前列腺相接觸，這一變細的部分稱膀胱頸。膀胱各部之間沒有明顯的界限。膀胱充盈時呈卵圓形。 First, the morphology of the bladder When the bladder is empty, it has a triangular pyramid shape. The tip of the bladder faces forward, which is called the tip of the bladder. The bottom is triangular, facing downward, called the bottom of bladder. The most part between the tip and the bottom is called the bladder body. The lower part of the bladder has an internal urethral orifice, which is in contact with the prostate. This thinned part is called the bladder neck. There is no obvious boundary between different parts of the bladder. The bladder is oval when filled. 切開膀胱前壁觀察膀胱內面時，可見粘膜由于膀胱肌層的收縮而形成許多皺襞，當膀胱膨脹時，皺襞可全部消失。但在膀胱底的內面有一三角形區(qū)域，由于缺少粘膜下層，粘膜與肌層緊密相連，無論在膀胱膨脹或收縮時，都保持平滑狀態(tài)，永不形成皺襞，此區(qū)稱為膀胱三角。膀胱三角位于兩輸尿管口與尿道內口之間。兩輸尿管口之間的橫行皺襞叫輸尿管間襞，粘膜深面有橫走的平滑肌束。膀胱鏡檢時，可見這一皺襞呈蒼白色，是尋找輸尿管口的標志。 When the front wall of the bladder is cut open to observe the inner surface of the bladder, it can be seen that many folds are formed in the mucosa due to the contraction of the bladder muscle layer, and all the folds can disappear when the bladder expands. However, there is a triangular area on the inner surface of the bottom of the bladder. Because of the lack of submucosa, the mucosa is closely connected with the muscularis, which keeps smooth when the bladder expands or contracts, and never forms folds. This area is called the bladder triangle. The triangle of bladder is located between the two ureteral orifices and the internal urethral orifice. The transverse fold between the two ureters is called the interureteric fold, and there are transverse smooth muscle bundles on the deep surface of the mucosa. Cystoscopy shows that this fold is pale, which is a sign of finding ureteral orifice. 膀胱三角的前下部，尿道內口的后方，于成年男子有因前列腺中葉而微凸的隆起，稱為膀胱垂。前列腺中葉肥大時,此處明顯凸起,可壓迫尿道造成排尿困難。膀胱三角為腫瘤和結核的好發(fā)部位，是膀胱鏡檢的重點區(qū)域，有重要臨床意義。 The anterior lower part of the bladder triangle, behind the urethral orifice, has a slight bulge due to the middle lobe of the prostate in adult men, which is called vesical uvula. When the middle lobe of the prostate is hypertrophy, it is obviously protruding here, which can compress the urethra and cause dysuria. The triangle of bladder is the most common site of tumor and tuberculosis, and it is the key area of cystoscopy, which has important clinical significance. 二、膀胱的位置 成人的膀胱位于小骨盆的前部，前方為恥骨聯(lián)合，后方在男性為精囊腺、輸精管壺腹和直腸，女性后方為子宮和陰道。膀胱頸在男性下鄰前列腺，在女性下方直接鄰接尿生殖膈。膀胱上面有腹膜覆蓋，男性鄰小腸，女性則有子宮伏于其上。 膀胱空虛時，膀胱尖不超過恥骨聯(lián)合上緣。膀胱充盈時，膀胱尖即上升至恥骨聯(lián)合以上，這時腹前壁折向膀胱的腹膜也隨之上移，使膀胱的前下壁直接與腹前壁相貼。此時在恥骨聯(lián)合上方進行膀胱穿刺或膀胱手術，可避免損傷腹膜和擾動腹膜腔。 新生兒膀胱的位置比成人的高，大部分位于腹腔內。隨著年齡的增長和盆腔的發(fā)育，膀胱的位置逐漸下降，約在青春期達成人位置。老年人因盆底肌肉松弛，膀胱位置更低。 三、膀胱壁的構造 膀胱壁由肌層、粘膜下組織和粘膜構成。外面覆以薄層疏松結締組織，漿膜層僅蓋在膀胱上面和膀胱底上部中間一小部分。肌層由平滑肌纖維組成，外層和內層多為縱行，中層主要為環(huán)行，三層相互交織不易分開。整個膀胱的肌層稱為膀胱逼尿肌，對排尿起重要作用。一般認為，男性平滑肌在尿道內口周圍呈環(huán)形排列，形成膀胱括約肌；在女性則多斜行或縱行,不形成明顯的括約肌。 第四節(jié) 尿道 男性尿道見男性生殖系統(tǒng)。女性尿道較男性尿道短、寬，且較直，長約 5cm，僅有排尿功能。起于膀胱的尿道內口，經陰道前方行向前下，與陰道前壁緊密相鄰，穿經尿生殖膈時有橫紋肌形成的尿道陰道括約肌環(huán)繞，可起隨意的括約作用。末端開口于陰道前庭。尿道下端周圍有尿道旁腺，導管開口于尿道外口附近。當腺體感染時可形成囊腫引起尿路阻塞。