What is the Difference Between Renal Papilla and Renal Pelvis

The key difference between renal papilla and renal pelvis is that the renal papilla is the apex of the renal pyramid, which projects into the pelvis, while the renal pelvis is the expanded front end of the ureter of the kidney.

The urinary system consists of kidneys, ureters, urinary bladder, and urethra. Kidneys are very important organs in the human body. It is located on each side of the spine. Healthy kidneys normally filter approximately a half cup of blood every minute. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters. The renal papilla and renal pelvis are two important parts of the kidneys.

CONTENTS

1. Overview and Key Difference
2. What is Renal Papilla  
3. What is Renal Pelvis
4. Similarities – Renal Papilla and Renal Pelvis
5. Renal Papilla vs. Renal Pelvis in Tabular Form
6. FAQ – Renal Papilla and Renal Pelvis
7. Summary – Renal Papilla vs. Renal Pelvis

What is Renal Papilla?

The renal papilla is described as the pointed end of each renal pyramid. It normally projects into a minor calyx. Minor calyx lies in the central space of the renal pelvis. Renal papilla has a sieve-like appearance. It also has many small openings on the surface. Each of these openings represents a small tubule called the papillary duct. The collecting tubules within the renal pyramid converge into these openings.

Anatomically, the renal papilla is located at the apex of the renal pyramids at the junction of the renal medulla and renal pelvis. Furthermore, the function of the renal papilla is to carry renal filtrate from the papillary ducts to the minor calyces of the renal pelvis through the papillary duct.

What is Renal Pelvis?

The renal pelvis is the portion of the kidney formed by the union of two or three calyces. It is also the region of the kidney most affected by different types of cancers. The renal pelvis is a large cavity or funnel-like dilated part that collects the urine as it is produced. Moreover, the renal pelvis is the structure by which the urine travels from the kidney into the ureter.

The peripheral part of the renal pelvis is interrupted by cuplike projections called calyces. Usually, a minor calyx surrounds the renal papillae of each pyramid and collects urine from that pyramid. Several minor calyces converge to form a major calyx. The urine flows into the ureter from the major calyces. Furthermore, the main function of the renal pelvis is to act like a funnel, collecting the urine produced in the kidney and leading it to a central stem called the ureter.

What are the Similarities Between Renal Papilla and Renal Pelvis?

• The renal papilla and renal pelvis are two important parts of the kidneys.
• Anatomically, the renal papilla and renal pelvis are related to each other.
• Both parts are very helpful in controlling urine flow.
• Both parts are affected by different diseases.

What is the Difference Between Renal Papilla and Renal Pelvis?

The renal papilla is the apex of the renal pyramid that projects into the pelvis, while the renal pelvis is the expanded front end of the ureter of the kidney. Thus, this is the key difference between renal papilla and renal pelvis. Furthermore, the renal papilla is a part affected by various infections, while the renal pelvis is a part affected by different types of cancers.

The infographic below presents the differences between renal papilla and renal pelvis in tabular form for side-by-side comparison.

FAQ: Renal Papilla and Renal Pelvis

What are the different types of renal pelvis?

Different types of renal pelvis are intrarenal, extrarenal, and borderline.

Is urine stored in the renal pelvis?

The urine is stored briefly in the renal pelvis before being transported through the ureter to the bladder where the urine is stored for a longer time (hours).

What does the renal pelvis look like?

The renal pelvis is an expanded funnel-shaped area.

Summary – Renal Papilla vs. Renal Pelvis

Kidneys are two reddish-brown bean-shaped, blood-filtering organs in the body. They also remove waste and balance body fluids. The renal papilla and renal pelvis are two structures found in the kidneys in humans. The renal papilla is located at the apex of the renal pyramids at the junction of the renal medulla and renal pelvis. However, the renal papilla is described as the pointed end of each renal pyramid, while the renal pelvis is the portion of the kidney formed by the union of two or three calyces. So, this summarizes the difference between renal papilla and renal pelvis.

Reference:

1. Roy, Shoummojit. “Renal Papilla.” One Stop Information on Anatomy.
2. “Kidney Pelvis – An Overview.” ScienceDirect Topics.

Image Courtesy:

1. “Slide5iii” By Anatomist90 – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Blausen 0592 KidneyAnatomy 01” By Blausen.com staff (2014).”Medical gallery of Blausen Medical 2014″. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia