Acute Kidney Injury
Histology of Normal Kidney
Lyz Boyd
Learning Objectives
By the end of this section, you will be able to:
- Identify the renal cortex and medulla of a kidney with H&E staining.
- Correlate the staining of the cytoplasm and nuclei with the function of the cells within the nephron
- Identify glomerulus and Bowmans capsule within the renal cortex
- Distinguish between a renal arteriole and vein
In the following video, we will learn what the kidney looks like microscopically and identify the structures we learned about in previous sections.
Histology of normal kidney DHPLC specimen PATH 304-020 normal rabbit kidney – created and presented by Lyz Boyd
Key Definitions:
- Epithelium – The layer of cells that covers all internal and external surfaces of the body, including the renal tubules.
- Podocytes – Specialized cells present in the glomeruli of the kidneys that create the filtration barrier, allowing fluid and small molecules to pass through while keeping larger proteins and cells in the blood.
- Bowman’s Space – The space surrounding the glomerulus that the filtrate initially passes into.
- Bowman’s Capsule – The membrane surrounding Bowman’s space.
- Brush Border – A feature of the cells of the proximal convoluted tubule that creates increased surface area for absorption.
- Lumen – The space inside a structure in the body, for example, the space that contains the filtrate in a renal tubule.
Nephrons are microscopic structures which filter blood to eliminate wastes via urine. Histologically, the cortex of the nephron comprises the glomeruli, Bowmans capsules, PCT, and DCT. The nephron loops (or Loop of Henle) are at the border of the cortex and medulla and form the renal pyramids. The collecting ducts travel from the cortex, through the medulla, and converge to form the renal papillae at the tip of the pyramids.
Glomeruli are easily recognized by its round structure (full of many capillaries and RBC), surrounded by a thin membrane (Bowmans capsule), separated by a slight space (Bowmans space). PCTs are recognized by its eosinophilic appearance and ‘fuzzy’ lumen which represents the brush border/microvilli that PCT uses to reabsorb nutrients out of the filtrate. In contrast, the loop, DCT, and collecting duct structures have a clear lumen.
- True
- False
2. Which cells are found in the glomerulus? Check all that apply.
- Capillary endothelial cells
- Red blood cells
- Antibodies/Immune cells
- Brush border
- Melanocytes
- Podocytes
3. Fill in the blanks.
The renal cortex contains the round _____ surrounded by its _____ capsule, _____ convoluted tubule with its brush border on the luminal side, and the _____ with is clear luminal space.
Answer Key
- True
- Capillary endothelial cells, Red blood cells, Podocytes
- glomerulus/glomerui, Bowman’s, proximal, distal convoluted tubule
The layer of cells that covers all internal and external surfaces of the body
Specialized cells present in the glomeruli of the kidneys that create the filtration barrier, allowing fluid and small molecules to pass through while keeping larger proteins and cells in the blood.
The space surrounding the glomerulus that the filtrate initially passes into.
cup-shaped sack lined by a simple squamous epithelium (parietal surface) and specialized cells called podocytes (visceral surface) that participate in the filtration process; receives the filtrate which then passes on to the PCTs
A feature of the cells of the proximal convoluted tubule that creates increased surface area for absorption.
interior of a tubular structure such as a blood vessel or a portion of the alimentary canal through which blood, chyme, or other substances travel
