Homeostasis I: A balancing act The basic principle of homeostasis is that if there is too much of something in the body, it will be eliminated, while if there’s too little of something, it will be retained.
Kidney: The kidneys are bean-shaped organs located behind the stomach that screen the body’s blood and remove wastes for subsequent excretion in the form of urine. The kidney has three regions: the outer cortex, the central medulla, and the inner pelvis.
Ureter: The ureters transport the urine from the kidneys to the bladder for storage.
Bladder: The bladder stores urine until the moment of elimination.
Nephron: The basic unit of the kidney is the nephron. Each kidney is composed of roughly 1 million nephrons. Kidney nephrons filter the blood, reabsorbing what the body needs and excreting the rest as urine.
Blood is continually filtered within Bowman’s capsule. Wastes and other solutes are passed into the tubule for inclusion in the urine, while large items like cells or large proteins are retained in the blood.
High pressure within the glomerulus allows small solutes and water to escape from the glomerular blood flow into the space of the Bowman’s capsule.
The renal tubule is the second portion of the nephron, and it is specialized for absorption. It descends from the Bowman’s capsule.