What Is a Ureter?

The ureter is connected to the renal pelvis and inferior to the bladder. It is a pair of slender tubes, which are in the shape of flat cylinders with an average diameter of 0.5 to 0.7 cm. The adult ureter is 25 to 35 cm in length, located behind the peritoneum, and descends vertically along the medial front of the psoas muscle into the pelvis. The ureter has three stenoses: one at the pelvis and ureteral transition (start of the ureter), one at the entrance past the small pelvis, and the last one entering the bladder wall. These stenoses are areas where stones, blood clots, and necrotic tissues tend to stay. The female ureter crosses the outside of the cervix to the bladder. Ureter-a special structure at the junction of the bladder, namely a Valdell sheath, which can effectively prevent the urine in the bladder from flowing back to the ureter.

[sh niào gun]

Ureter connection

Ureteral blood supply

The upper 1/3 is supplied by the renal artery branch, the middle 1/3 is supplied by the abdominal aorta, common iliac artery, internal spermatic artery or uterine artery, and the lower 1/3 is supplied by the inferior bladder artery. After these branches reach the ureter, they are distributed in the fascia layer and communicate up and down to form an arterial network, and then spread to other layers. Therefore, when ureteral transplantation is performed, cutting off 1/3 of the blood flow has little effect on the blood supply of the transplanted part. The ureter vein returns with the arteries. The veins return to the fascial layer through the submucosa, and then return to the veins of the kidney, iliac crest, spermatic cord, uterus, and bladder.

The ureteral nerve is an autonomic nerve, which comes from the kidney and the sub-abdominal nerve plexus. It is reticulated in the connective tissue of the ureter and then enters the muscular layer. Most ganglion cells are seen at the lower end of the ureter, a few are at the upper end and few in the middle. Due to the peristalsis of the ureter, it can be changed by drugs similar to the sympathetic and parasympathetic nerves. Even if these nerves are injured, the peristalsis of the ureter is not affected.

Ureteropelvic physiology

The main function of the pelvis and ureter is to introduce urine excreted by the kidneys into the bladder. The power to transport urine is the function of filtration pressure and the contraction of the renal pelvis and ureter smooth muscle. The ureter is a pair of slender muscular tubes that starts from the kidney and finally the bladder. The ureter of an adult is about 25-30 cm long. (I) Position of the ureter The ureter is located at the back of the peritoneum, descending along the front of the psoas muscle and over the upper edge of the small pelvis, where the right ureter crosses the front of the right external iliac artery; the left ureter crosses the front of the left common iliac artery. After entering the small pelvis, they move forward and inward, diagonally through the bladder wall, and open in the bladder.

(2) Physiological stenosis of the ureter There are 3 physiological stenosis of the ureter: the first stenosis is at the beginning of the ureter, that is, the transition site of the kidney and the ureter; the second stenosis is at the place that crosses the iliac vessels (equivalent to the upper pelvis) Horizontal); the third stenosis is through the bladder wall. Urinary stones are often incarcerated in these narrow areas, causing smooth muscle spasm of the wall, severe colic, or urinary tract obstruction.

Ureteral segmentation

The ureter is a slender muscular tube, one on each side, the average length is 26.5cm for men, 25.9cm for women, and the diameter is about 0.5 to 0.7cm. Starting from the lower end of the renal pelvis, and finally the bladder. The ureter has a thicker smooth muscle layer. It can be used for rhythmic peristalsis to make urine continuously flow into the bladder. Excessive expansion due to stone blockage can produce spasmodic contractions and pain, namely renal colic. The ureter can be divided into abdominal section, pelvic section and inner wall section according to the behavior. After the ureter starts from the lower end of the renal pelvis, it descends along the front of the psoas muscle on the deep side of the abdominal wall and the peritoneum. At the entrance of the small pelvis, the left and right ureters cross the end of the left common iliac artery and the front of the right iliac artery, respectively. This segment is called the abdominal segment. Enter the pelvic cavity from the iliac blood vessel, first down the back of the pelvic wall and over the surface of the vascular nerves of the pelvic wall, and turn around the sciatic spine level into the anterior upper corner of the bladder. In women, the ureter passes through the outside of the cervix, above the vaginal dome, about 1.5 to 2 cm from the cervix, where the uterine artery crosses the front of the uterus; in men, the vas deferens crosses the front of the ureter.

The ureter starts from the outer upper corner of the bottom of the bladder and penetrates the bladder wall obliquely inward and downward. The ureteric orifice at the ureteral orifice opens into the bladder. This part is called the inner wall segment and is about 1.5 to 2.0 cm long. When the bladder is full, the internal pressure of the bladder increases, squashes the inner wall and closes the lumen, which prevents the urine in the bladder from flowing back into the ureter. Due to the peristalsis of the ureter, urine can still enter the bladder continuously. If the inner wall segment is too short or the surrounding muscular tissue is poorly developed, urine reflux may also occur. Narrow part of the ureter: where the renal pelvis and ureter migrate; where it intersects with the iliac vessels; inside the wall. These stenoses are often the site of ureteral stones.

Treatment of ureteral stones

Urinary stones are one of the most common urological diseases. More men than women, about 3: 1. Over the past 30 years, the incidence of stones in the upper urinary tract (kidney, ureter) in China has increased significantly. The mechanism of stone formation has not been fully elucidated, and it is believed to be related to metabolic and infectious factors. Symptoms: The main symptoms are pain and hematuria. Very few patients may have no symptoms for a long time.

(A) Pain: Most patients have low back pain or abdominal pain. Larger stones are mostly dull or dull pain on the affected side, often aggravated after exercise; smaller stones, which often cause smooth muscle spasms and colic, often occur suddenly, and the pain is severe, such as a knife cut. Radiation down to the abdomen, vulva and inner thighs. Sometimes patients are accompanied by pale, cold sweats, nausea, and vomiting. In severe cases, symptoms such as weak and fast pulses, and decreased blood pressure are present. Pain is often paroxysmal, or it can be suddenly stopped or relieved due to a certain movement pain, and there is a dull pain in the waist and abdomen.

(B) Hematuria: Because stones directly damage the kidney and ureter's mucous membranes, microscopic hematuria or gross hematuria often occurs after severe pain. The severity of hematuria is related to the degree of damage.

(3) Pyuria: Pus cells appear in the urine when kidney and ureteral stones are complicated by infection, and high fever and low back pain can occur clinically.

(4) Others: Stone obstruction can cause hydronephrosis and renal insufficiency, and some patients may still have gastrointestinal symptoms, anemia, and so on.

The treatment of kidney and ureteral stones should be specifically analyzed according to the size, location, number, shape, one or both sides of the stones, whether there is urinary obstruction, concomitant infection, degree of impaired renal function, general conditions, and treatment conditions. Comprehensive analysis consider. However, when colic occurs, symptoms should be relieved first, and then a treatment plan should be selected.