Major calyx

Major calyx Definition

It is one of the recesses or branches of the pelvis of your kidney wherein the orifices of the renal pelvis branch out. Calyx is defined as a cavity or cup-shaped organ. In simple words, the Major Calyx is a cup-shaped part of kidney’s renal pelvis that surrounds the renal papilla.

It refers to a fusion of the minor calyxes in the body. It is a section of the kidney that is actually a division of the pelvis into 2-3 tubes that are divided into a number of minor calyces – usually 8-14.

To put up a simpler picture, the kidney is divided into three parts- renal medulla, renal cortex and the renal pelvis (these parts receives urine from the major calyces). The urine that is first formed in the kidney passes through the renal papilla in the minor calyx.

There are two or three minor calyces that converge to form the Major Calyx. The urine then continues from the minor calyx to the Major Calyx and passes through the renal pelvis in the ureter.

Major calyx Anatomy

This section of the kidney appears as a large chamber. It is funnel-shaped in appearance. The Major Calyx is formed by two or three minor calyces that drain from many renal papillae. The major calyces form a large collecting duct, called the renal pelvis, in the kidney that is protected by the renal sinus.

Major Calyx Division

There are several minor calyces that connect to three major calyces. These three major calyces then connect to the renal pelvis, which is positioned in the middle of the kidney. It is connected to the renal hilus that drains out urine to the ureter. Then the urine drains into the bladder and is eventually flushed out from the body.

Major Calyx Lining

Major Calyx epithelium is called the Transitional Epithelium, which is the lining of the major calyces, minor calyces, ureter and renal pelvis.

Major Calyx Function

This kidney structure enwraps the apex of the renal pyramids. Following production in the kidney, urine enters into a minor calyx following a passage through a renal papilla located at the apex. It then enters into the Major calyx and is passed into the ureter through the renal pelvis.

The growth of peristalsis combined with pacemaker cells in the smooth muscles of the major calyces allows propelling the urine via the ureters and the renal pelvis to the bladder. It should be remembered that the urine entering the kidney is first collected in the renal pelvis which is formed by Major Calyces.

The initiation of the movement of urine is actually caused by the volume of urine in the duct. The more the volume, the more it stretches the walls of the renal calyces that trigger impulses which in turn stimulate rhythmical relaxation and contraction.

It should, however, be taken note of the calyces (both minor and major calyces) can become swollen and dilated with extra fluid or infections in it. The condition is medically termed ‘Caliectasis’ that is triggered by urinary tract infections affecting the kidneys. The condition usually remains undetected unless the person is tested for some other tests.

Major Calyx Disease – Symptoms of Caliectasis

Caliectasis does not show any symptoms normally, but there are certain signs causing the condition:

  • Increased urge to often urinate
  • Blood noticeable in urine
  • Trouble while urinating
  • Pus in urine
  • Foul-smelling urine
  • Abdominal tenderness and pain

Major Calyx Disease – Causes of Caliectasis

  • Cysts or tumors
  • Blockage in kidneys (this is usually caused by a birth defect)n
  • Kidney stones
  • Renal fibrosis
  • Hydronephrosis (urine buildup)
  • Urologic or renal tuberculosis
  • Urinary tract obstruction (UTO)
  • Urinary tract infections
  • Kidney infections
  • Kidney cancer
  • Bladder cancer

Major Calyx Disease – Diagnosis of Caliectasis

The diagnostic procedures for Caliectasis include:

  • Physical exam– A thorough physical examination is performed by the doctor to understand if there is any tenderness or swelling around the kidney area.
  • Urinalysis– It is a test done by taking a urine sample.
  • Ultrasound– Doctors perform an abdominal ultrasound test to diagnose any extra fluids collected in the kidneys or if there are any foreign objects present there.
  • Urography– The procedure uses contrast dye and a CT scan to get a clear view of your kidneys.
  • Cystoscopy– A urethra is inserted inside your body with a camera at its one end to take pictures of the inside of the bladder and your kidneys.

Major Calyx Disease – Treatment for Caliectasis

The treatment options chosen by the doctor depends upon the underlying of caliectasis. The several options include:

  • Surgery for removal or kidney stones or tumors
  • Catheters or nephrostomy tubes to drain urine
  • Antibiotics for infections

The condition of Caliectasis is triggered by any underlying problems as traced in the kidneys. Although in most of the cases Caliectasis is often undetected it is often diagnosed when conducting other tests for related kidney issues. The problem, once detected, should be treated right away, otherwise, it may lead to permanent kidney damage.

Major calyx Pictures

These are some useful images that would help you to understand the physical appearance of this kidney section.

Picture of Major calyx

Picture 1 – Major calyx

 Image of Major calyx

Picture 2 – Major calyx Image


Last updated on November 14th, 2018 at 8:11 pm

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