The upper 1/3 of the ureter is supplied by the renal artery branches, 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 vesical 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 performing ureteral transplantation, cutting off the lower 1/3 of the blood flow will have little impact on the blood supply to the transplanted part. The ureteral veins drain along with the arteries. The veins return to the fascial layer through the submucosa and then return to the renal, iliac, spermatic cord, uterine, and bladder veins.

The ureteral nerve is an autonomic nerve, coming from the kidneys and hypogastric plexus. It is distributed in the connective tissue of the ureter in a network shape, and then enters the muscle layer. Most ganglion cells are found in the lower end of the ureter, a few are found in the upper end, and very few are found in the middle section. Since the peristalsis of the ureter can be changed by drugs similar to sympathetic and parasympathetic nerves, even if these nerves are injured, the peristalsis of the ureter will not be affected. The main function of the renal pelvis and ureter is to conduct urine excreted by the kidneys into the bladder. The force that transports urine is the effect of filtration pressure and contraction of the smooth muscles of the renal pelvis and ureter. The ureters are a pair of slender muscular tubes that originate from the kidneys and end at the bladder. The adult ureters are about 25 to 30cm long. (1) Location of the ureter: The ureter is located behind the peritoneum, descends in front of the psoas major muscle, and crosses the upper edge of the small pelvis, where the right ureter crosses in front of the right external iliac artery; the left ureter crosses in front of the left common iliac artery. After entering the small pelvis, they travel forward and inward, penetrate the bladder wall obliquely, and open into the bladder.

(2) Physiological stenosis of the ureter There are three physiological stenosis in the ureter: the first stenosis is at the beginning of the ureter, that is, the transition point between the kidney and the ureter; the second stenosis crosses the iliac blood vessels (equivalent to the level of the upper mouth of the pelvis); the third stenosis is where it passes through the bladder wall. Urinary tract stones are often embedded in these narrow parts, causing spasm of smooth muscle in the wall, causing severe cramping or urinary tract obstruction and other symptoms. The ureter is a slender muscular tube, one on each side. The average length is 26.5cm in men and 25.9cm in women. The diameter is about 0.5-0.7cm. It starts from the lower end of the renal pelvis and ends in the bladder. The ureter has a thick smooth muscle layer. It can perform rhythmic peristalsis to keep urine flowing into the bladder. If it is over-expanded due to stone obstruction, it can cause spasmodic contraction and pain, which is renal colic. The ureter can be divided into abdominal segment, pelvic segment and intramural segment according to its course. After starting from the lower end of the renal pelvis, the ureter descends on the deep surface of the peritoneum of the posterior abdominal wall and along the front of the psoas major muscle. Reaching the entrance of the small pelvis, the left and right ureters pass in front of the end of the left common iliac artery and the beginning of the right iliac artery respectively. This segment is called the abdominal segment. It enters the pelvic cavity from the iliac blood vessels, first down and back along the side wall of the pelvis, crossing the surface of the blood vessels and nerves in the pelvic wall, turning around at the level of the ischial spine, turning anteromedially and penetrating into the outer upper corner of the bladder floor. This section is called the pelvic segment. In women, the ureter passes on the outside of the cervix and above the side of the vaginal dome, about 1.5 to 2 cm away from the cervix, where the uterine artery crosses the front and top of it; in men, the vas deferens crosses in front of the lower end of the ureter.

The ureter starts from the upper outer corner of the bladder base, passes through the bladder wall obliquely inward and downward, and opens into the bladder at the ureteric orifice. This part is called the intramural segment, which is about 1.5 to 2.0cm long. When the bladder is full, the intravesical pressure increases, which flattens the inner wall and closes the lumen, preventing urine in the bladder from flowing back into the ureter. Due to the peristalsis of the ureters, urine can still continue to enter the bladder. If the intramural segment is too short or the surrounding muscle tissue is underdeveloped, urinary reflux may also occur. The stenotic part of the ureter: ① The transition point between the renal pelvis and the ureter; ② The intersection with the iliac blood vessels; ③ The intramural segment. These strictures are often sites of retention of ureteral stones. Urinary tract stones are one of the most common urological diseases. There are more males than females, about 3:1. In the past 30 years, the incidence of upper urinary tract (kidney, ureter) stones has increased significantly in China. The mechanism of stone formation has not been fully elucidated, but it is believed to be related to metabolic and infectious factors. Symptoms: The main symptoms are pain and hematuria, and a very small number of patients may remain asymptomatic for a long time.

(1) Pain: Most patients experience low back pain or abdominal pain. Larger stones usually cause dull or dull pain in the waist of the affected side, which is often aggravated after activity; smaller stones often cause smooth muscle spasm and colic, which often occurs suddenly and causes severe pain, like a knife cutting. Radiate to the lower abdomen, vulva, and inner thighs. Sometimes patients are accompanied by pale complexion, cold sweats, nausea, and vomiting. In severe cases, symptoms such as weak and fast pulse and decreased blood pressure may occur. The pain often occurs in paroxysms, or may suddenly stop or relieve due to a certain movement, leaving behind a dull pain in the waist and abdomen.

(2) Hematuria: Because stones directly damage the mucous membranes of the kidneys and ureters, microscopic hematuria or gross hematuria often occurs after severe pain. The severity of the hematuria is related to the degree of damage.

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

(4) Others: Stone obstruction can cause hydronephrosis, renal insufficiency, and some patients may even develop gastrointestinal symptoms, anemia, etc.

The treatment of kidney and ureteral stones should be based on the stone size, location, number, shape, one or both sides, whether there is urinary flow obstruction, associated infection, degree of renal function impairment, systemic condition and treatment Conduct detailed analysis and comprehensive consideration of conditions, etc.

But when colic attacks, symptoms should be relieved first, and then treatment options should be chosen.