Our kidneys are a pair of fist-sized organs that serve to filter our blood, removing waste as well as excess water via urine. They’re located on either side of the spine in the retroperitoneal space–aka our mid-to-lower back. The kidneys are protected by layers of fat, muscle, and our ribcage. When at rest, the kidneys receive about 25% of our cardiac output.
The kidney’s inside has an outer section known as the renal cortex, and as an inner section known as the medulla. The renal pyramids, which aid in moving urine along the excretory process, are found inside the medulla. The renal papillae are bundled collection ducts which function to move urine made in the nephrons to the calyces, an area they pass on their way to being excreted in the form of urine.
Each of our kidneys contain approximately one million nephrons, which are their filtering units. Within each nephron is the glomerulus, which is the filter itself, as well as a tubule. The nephron functions in a process that’s twofold:
When your blood flows into a nephron, it enters the glomerulus, which is made up of a cluster of tiny blood vessels. The glomerulus is made up of thin walls, which allows wastes, fluid (think water), and smaller molecules to easily pass into the tubule while keeping larger molecules such as blood cells and proteins in the blood vessel. The tubule then returns the necessary substances to your blood via a blood vessel that runs alongside it, while removing waste products. The nearby blood vessel reabsorbs practically all of the water, as well as nutrients and minerals our bodies need to function and be healthy, while the tubule helps remove extra acid and other wastes from our blood. The leftover waste products and fluid in the tubule, finally, turn into urine.
The Ezra MRI screens your kidneys and the accompanying adrenal glands for cancer and other anomalies. You may learn more about our screening packages here.