Ureter
Encyclopedia
In human anatomy
, the ureters are muscular tubes that propel urine
from the kidney
s to the urinary bladder
. In the adult, the ureters are usually 25–30 cm (9.8–11.8 in) long and ~3-4 mm in diameter.
In humans, the ureters arise from the renal pelvis
on the medial aspect of each kidney before descending towards the bladder on the front of the psoas major muscle. The ureters cross the pelvic brim
near the bifurcation of the iliac arteries (which they cross anteriorly). This is a common site for the impaction of kidney stones (the others being the ureterovesical valve, where the ureter meets the bladder, and the pelviureteric junction, where the renal pelvis meets the ureter in the renal hilum). The ureters run posteroinferiorly on the lateral walls of the pelvis and then curve anteriormedially to enter the bladder through the back, at the vesicoureteric junction, running within the wall of the bladder for a few centimetres. The backflow of urine is prevented by valves known as ureterovesical valves.
In females, the ureters pass through the mesometrium
and under the uterine arteries on the way to the urinary bladder
.
Ureters are also found in all other amniote
species, although different ducts fulfill the same role in amphibian
s and fish
.
.
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
, the ureters are muscular tubes that propel urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
from the kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
s to the urinary bladder
Urinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
. In the adult, the ureters are usually 25–30 cm (9.8–11.8 in) long and ~3-4 mm in diameter.
In humans, the ureters arise from the renal pelvis
Renal pelvis
The renal pelvis or pyelum is the funnel-like dilated proximal part of the ureter in the kidney.In humans, the renal pelvis is the point of convergence of two or three major calyces...
on the medial aspect of each kidney before descending towards the bladder on the front of the psoas major muscle. The ureters cross the pelvic brim
Pelvic brim
The pelvic brim is the edge of the pelvic inlet. It is an approximately apple-shaped line passing through the prominence of the sacrum, the arcuate and pectineal lines, and the upper margin of the pubic symphysis....
near the bifurcation of the iliac arteries (which they cross anteriorly). This is a common site for the impaction of kidney stones (the others being the ureterovesical valve, where the ureter meets the bladder, and the pelviureteric junction, where the renal pelvis meets the ureter in the renal hilum). The ureters run posteroinferiorly on the lateral walls of the pelvis and then curve anteriormedially to enter the bladder through the back, at the vesicoureteric junction, running within the wall of the bladder for a few centimetres. The backflow of urine is prevented by valves known as ureterovesical valves.
In females, the ureters pass through the mesometrium
Mesometrium
The mesometrium is the mesentery of the uterus. It constitutes the majority of the broad ligament of the uterus, excluding only the portions adjacent to the uterine tube and ovary.It is adjacent to the mesosalpinx....
and under the uterine arteries on the way to the urinary bladder
Urinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
.
Ureters are also found in all other amniote
Amniote
The amniotes are a group of tetrapods that have a terrestrially adapted egg. They include synapsids and sauropsids , as well as their fossil ancestors. Amniote embryos, whether laid as eggs or carried by the female, are protected and aided by several extensive membranes...
species, although different ducts fulfill the same role in amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s and fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
.
Clinical
The ureter is sometimes injured in hysterectomies near the infundibulopelvic (suspensory) ligament or where the ureter courses posterior to the uterine vesselsUterine artery
-Structure:The uterine artery usually arises from the anterior division of the internal iliac artery. It travels to the uterus, crossing the ureter anteriorly, reaching the uterus by traveling in the cardinal ligament....
.
External links
- Clinical Anatomy of Ureter | Medchrome - "Posterior Abdominal Wall: Internal Structure of a Kidney" - "Relationship of the ureter to the uterine artery." - "Mid-sagittal section of male pelvis." - "Mammal, ureter (LM, Medium)" - "Ureter"