Structure of the Kidney

What is the central cavity that the hilum renale expands into?

What does the sinus renalis contain?

What lines the sinus renalis?

What are the main components of the kidney parenchyma?

The cortex of the kidney is dark brown in color, soft, and granular.

What is the width of the cortex renalis?

What structures extend from the parts of the cortex into the medulla?

What are the stripes radiating from the medulla to the cortex called?

What is the color of the medulla and what does it consist of?

What forms from the portion of the cortex adjacent to the pyramid?

What do lobi renales form?

Where are the bases of the pyramids directed?

Where do the apices of the pyramids point?

What are the openings on the papilla renalis through which urine is secreted called?

What surrounds each papilla?

What do the calyces renalis minor unite to form?

What is formed by the fusion of calyces renalis major?

What happens as the pelvis renalis leaves the sinus renalis?

Structure of the Kidney

Hilum renale expands into a central cavity known as sinus renalis.
The sinus renalis contains pelvis renalis and calyces renales, surrounded by adipose tissue housing branches of blood vessels and nerves.
Lined by a continuation of capsula fibrosa, providing protection and structure.
Kidney parenchyma is composed of cortex (outer layer) and medulla (inner layer).

Cortex Characteristics

Cortex renalis, or the outer layer, is dark brown, soft, and granular.
The cortex is approximately 4-5 mm wide.
Cortical parts extend into the medulla as columnae renales, supporting both structure and function.
Medullary rays, or radii medulares, are stripes radiating from the medulla to the cortex.

Medulla Composition

Medulla appears light brown and consists of striated conical structures known as pyramides renales, numbering between 12 and 15.
Each pyramidal base is directed towards the cortex, while their pointed apices are directed towards the pelvis renis.
Several apices fuse to create a structure called papilla renalis.

Urinary Pathway Formation

On the papilla renalis, foramina papillaria are present, serving as points through which urine is secreted.
Each papilla renalis is surrounded by a calyx renalis minor, collecting urine from the papillae.
These minor calyces unite to form calyx renalis major, usually 2-3 in number.
The fusion of major calyces creates a funnel-shaped sac called pelvis renalis (or pyelon).
As pelvis renalis exits sinus renalis, it reduces in size before continuing as ureter, transporting urine to the bladder.

Explore the anatomy of the kidney, including its central cavity, protective layers, and the composition of its cortex and medulla. This quiz will test your understanding of the kidney's structure, including its parenchyma and functional components.