The renal calyceal system is a part of the kidney that collects urine and passes it on to the renal pelvis.
Structure and function
The renal calyceal system is made up of several small hollow spaces that are shaped like funnels. These are called renal calyces. They collect the urine that is produced in the tiny structures known as renal corpuscles. The calyces gather the urine and pass it along to the renal pelvis. From there, it travels through the ureter and into the bladder.
The kidney is an important organ that filters the blood and removes waste products. The renal calyceal system is the collection point for freshly produced urine. Without this system, the body's waste products could not be properly removed.
Where exactly is the renal calyceal system?
Inside the kidney sits the renal pelvis, also known as the pyelon. The renal calyceal system sits directly in front of it and is made up of several small calyces that open like fingers into a central hollow space, the renal pelvis. Each calyx collects urine from a small area of the kidney. The small calyces (known as calices minores) join together to form larger calyces (calices majores), which then drain into the renal pelvis.
Significance in medical reports
The term renal calyceal system appears frequently in reports from ultrasound scans, CT scans, or MRI scans of the kidneys. When the renal calyceal system is described, it usually concerns an assessment of whether urine is draining freely or whether there are signs of a narrowing, a backflow, or other abnormalities.
Typical phrases in reports include, for example, "unremarkable renal calyceal system", "renal calyceal system not dilated", or "signs of calyceal dilatation". This means the doctor is checking whether the system looks normal or whether there are signs of a blockage or another problem.
What happens when the renal calyceal system is changed?
Changes to the renal calyceal system are not a disease in themselves, but rather a sign that something is not quite right with the way urine is being produced or drained. A common reason for dilatation can be a backflow of urine, for example caused by a stone, a narrowing, or an inflammation. In such cases, this is referred to as hydronephrosis. The exact causes and treatment options always depend on the individual findings.
Why is the renal calyceal system important?
Without a working renal calyceal system, the kidney cannot drain urine properly. This would cause waste products to build up in the body, which would be harmful over time. It is therefore important that this system remains clear and unobstructed. If there are any abnormalities in the renal calyceal system, it is sensible to find out the cause and, if necessary, to have further investigations carried out.
Summary
The renal calyceal system is an anatomical part of the kidney that collects and passes on urine. It has no disease significance of its own and is a normal structural element. Abnormalities in the renal calyceal system are usually discovered during imaging investigations and may point to problems with urine drainage. The exact significance always depends on the context of the findings.
