The kidney is composed of the following:

Cortex: composes the darker outer region of the kidney. It is composed of renal corpuscles, cortical labyrinths, and medullary rays. The renal corpuscles are spherical structures that form ultrafiltrate from blood. The cortical labyrinths are regions between renal corpuscles and medullary rays that contain proximal and distal convoluted tubules, and the medullary rays are projection of tubules between the cortex and the medulla that contains straight tubules and collecting ducts.

Medulla: the lighter inner region of your kidney. It is composed of pyramids and the renal pelvis. The pyramids form conical structures whose base faces the cortex and their apex forms the renal papilla. The renal pelvis is a funnel-shaped origin of the ureter.

Arcuate arteries: branches of interlobular arteries that form an arcade over the pyramids at the junction of the cortex and medulla.

Hilum: a concave surface with a deep fissure in which vessels enter and exit the kidney.

From the cross-section of the ureter we can see that it is composed of the following:

Urothelium: Transitional epithelium that consists of two to three cell layers in the upper ureter with up to ten cell layers near the bladder. It is composed of umbrella cells, upper layer of cells that change shape depending on the distention of the ureter.

Lamina propria: thick layer of dense irregular connective tissue rich in collagen and elastic fibers

Muscularis external: irregular arrangement of smooth muscle in two layers in the upper ureter or three layers near the bladder

Adventitia: loose connective tissue with blood vessels, nerves, and adipose cells

The bladder is composed of the following:

Urothelium: transitional epithelium consists of two to three cell layers in the upper ureter with up to ten cell layers near the bladder. It is composed of umbrella cells, cells that change shape depending on the distention of the bladder. Umbrella cells are frequently binucleate.

Lamina propria: thick layer of dense irregular connective tissue rich in collagen and elastic fibers.

Muscularis externa: loosely arranged smooth muscle in two layers (inner longitudinal and outer circular) in the upper ureter or three layers (inner longitudinal, middle circular and outer longitudinal) near the bladder.

Adventitia: loose connective tissue with blood vessels, nerves, and adipose cells.