renal medulla

anatomy

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June 17, 2026

Quick Summary

The renal medulla is the inner part of the kidney, composed of triangular sections of tissue called renal pyramids. These pyramids contain tubules that transport urine from the outer cortex, where it's produced, to the calyces. The pointed end of each pyramid, the papilla, projects into a calyx and has many small openings where urine droplets exit.12

Within the nephrons of the kidney, the loop of Henle is a U-shaped tubule crucial for recovering water and sodium chloride from urine. This process allows the kidney to produce concentrated urine, which is vital for conserving water, especially in arid environments. The loop of Henle, along with the distal convoluted tubule and collecting ducts, plays a key role in concentrating urine and regulating water and electrolyte balance.34567

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renal collecting tubule
…the tissue of the kidney’s medulla, or inner substance, contains a high concentration of sodium. As the collecting tubules travel through the medulla, the concentration of sodium causes water to be extracted through the tubule walls into the medulla. The water diffuses out between the collecting wall cells until the…
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…the tissue of the kidney’s medulla, or inner substance, contains a high concentration of sodium. As the collecting tubules travel through the medulla, the concentration of sodium causes water to be extracted through the tubule walls into the medulla. The water diffuses out between the collecting wall cells until the…
Read More

renal system
Internal configuration
The innermost tissue, called the renal medulla, forms comparatively dark cones, called renal pyramids, with bases outward and apexes projecting, either singly or in groups, into the renal sinus. Each projection of one or more pyramid apexes into the sinus is known as a renal papilla. The bases of these…
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The innermost tissue, called the renal medulla, forms comparatively dark cones, called renal pyramids, with bases outward and apexes projecting, either singly or in groups, into the renal sinus. Each projection of one or more pyramid apexes into the sinus is known as a renal papilla. The bases of these…
Read More