Three physiological strictures of the ureter

The urethra tube connects to the renal pelvis above and the bladder below. It is a pair of long and thin tubes in the shape of a flat cylinder with an average diameter of 0.5 to 0.7 cm. The total length of the adult urethra is 25 to 35 cm. It is located behind the peritoneum and descends vertically along the front of the inner side of the psoas major muscle into the pelvis. The urethra has three narrow parts: one at the transition between the renal pelvis and the urethra (where the urethra begins and ends), one at the entrance over the pelvic bone, and the last one at the inside of the bladder wall. This narrow area is where stones, blood clots and necrotic tissue are most likely to accumulate. The female urethral tube goes over the sides of the cervix to the bladder.

Urethra human body part

The urethra tube originates from the renal pelvis in the middle, descends on the surface of the psoas major muscle, passes through the common iliac artery and vein, enters the pelvis, descends along the pelvic wall, passes through the front and upper side of the sacroiliac joint, turns inward at the turning point of the ischial spine, obliquely passes through the bladder wall, and opens into the bladder.

Total length 20-30 cm. The function of the urethra is to transport urine.

There are three narrownesses in the urethra: the first narrowness is at the transition between the renal pelvis and the urethra (where the urethra starts and ends); the second narrowness is where it passes through the iliac artery and enters the pelvis; the third narrowness is where it penetrates the bladder wall. When kidney stones slide down with urine, they are easy to get stuck in the narrow part of the urethra, causing severe pain in the urethra and obstruction of urination.

The urethra can be divided into three parts according to its shape: the blood pressure urethra, the abdominal blood urethra, the pelvic urethra and the supplementary urethra. Three narrow places: the starting and ending point of the blood pressure urethra tube; the entrance where blood flows beyond the pelvic bone; and the place where blood flows obliquely through the bladder wall.

Urethra tube basic introduction

The urethra is located behind the peritoneum. It is a tubular structure composed of muscle and mucosa. It starts from the renal pelvis and ends at the bladder triangle. The diameter of the men's tube is 27-30 cm, with an average of 28 cm; the diameter of the women's tube is 25-28 cm, with an average of 26 cm. The right side is about 1 cm shorter than the left side. In clinical medicine, the urethra is divided into three sections: upper, middle and lower, which can also be called the abdominal section, pelvic section and bladder section. The abdominal section extends from the junction of the renal pelvis and urethra to the point beyond the iliac artery. Pelvic segment, from the iliac arteries to the bladder wall. The bladder segment runs obliquely from the bladder wall to the bladder mucosa and urethral opening. The abdominal segment of the right urethra descends behind the peritoneum along the front of the psoas major muscle, and then enters the pelvis through the root of the mesentery and the tail end of the ileum. The initial part is located behind the descending and transverse part of the duodenum, between the duodenum and the jejunal and ileal mesentery. This section of the urethra is turned over in front of the spermatic flexure, the right sigmoid colon and the ileosigmoid blood vessels, and is similar to the appendix in the iliac fossa. Therefore, appendicitis behind the cecum often causes right ureteritis, and blood cells and pus cells may appear in the urine. The pelvic and bladder sections of the urethra account for half of the total length of the urethra. It passes through the pelvic edge in front of the common iliac artery, and then reaches the bottom of the bladder between the internal iliac artery and the retroperitoneum. In men, it crosses the ejaculatory duct and enters the bladder. The bladder section of the urethra forms a blunt angle with the bladder when entering the bladder, then moves obliquely downward, passes through the bladder wall layer inward, and opens at both ends of the urethral ridge in the bladder trigone. The distance between the left and right tubes is about 2.5 cm. The urethral mucosa and bladder mucosa are connected to each other, and the urethral longitudinal muscles and bladder trigone muscles are also connected.