Kidney anatomy, with pyramids labeled at right
Renal pyramids (or malpighian pyramids or Malpighi's pyramids named after Marcello Malpighi, a seventeenth-century anatomist) are cone-shaped tissues of the kidney. In humans, the renal medulla is made up of 10 to 18 of these conical subdivisions. The broad base of each pyramid faces the renal cortex, and its apex, or papilla, points internally. The pyramids appear striped because they are formed by straight parallel segments of nephrons and collecting ducts. The base of each pyramid originates at the corticomedullary border and the apex terminates in a papilla, which lies within a minor calyx, made of parallel bundles of urine collecting tubules.
- Frontal section through the kidney
- Young, Barbara; O'Dowd, Geraldine; Woodford, Phillip (2014). Wheater's Functional Histology (6 ed.). Philadelphia, PA: Elsevier. p. 293. ISBN 978-0-7020-4747-3.
- Anatomy figure: 40:03-02 at Human Anatomy Online, SUNY Downstate Medical Center