Related Concept Videos

Filtration and Urine Formation01:32

Filtration and Urine Formation

The function of the kidneys is to filter, reabsorb, secrete, and excrete. Every day the kidneys filter nearly 180 liters of blood, initially removing water and solutes but ultimately returning nearly all filtrates into circulation with the help of osmoregulatory hormones. This process removes wastes and toxins but is also crucial to maintain water and electrolyte levels. Most of these functions are performed by the tiny but numerous nephrons contained within the kidneys.
Comparative Excretory Systems02:24

Comparative Excretory Systems

Animals have evolved different strategies for excretion, the removal of waste from the body. Most waste must be dissolved in water to be excreted, so an animal’s excretory strategy directly affects its water balance.
Kidney Structure01:45

Kidney Structure

The kidneys are two large bean-shaped organs located in the upper abdomen. They filter the blood several times a day to remove toxins and rebalance water and electrolytes of the circulatory system via the renal veins. The kidneys receive blood directly from the heart via the renal arteries. These arteries enter the kidney at the hilum, the concave surface of the bean, where they branch and divide into smaller vessels and capillaries.
Hormonal Regulation01:33

Hormonal Regulation

The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream.
Hormonal Regulation02:03

Hormonal Regulation

Hormones regulate a significant portion of digestion through activation of the neuroendocrine system. The neuroendocrine system of digestion contains many different hormones all with multiple functions that are both, directly and indirectly, involved in digestion.The ProcessStarting in the stomach, when proteins are detected by sensory neurons of the enteric nervous system, the pyloric gland is stimulated to release gastrin. In turn, this hormone induces the release of histamine. Combined, they...
Urinary Tract Calculi II: Pathophysiology and Clinical Manifestations01:26

Urinary Tract Calculi II: Pathophysiology and Clinical Manifestations

Renal calculi, commonly termed kidney stones, are crystalline solid masses that form in the kidneys but can occur at any point within the urinary system, encompassing the kidneys, ureters, bladder, and urethra.The pathophysiology of renal stones involves several key factors: supersaturation of the urine with stone-forming constituents, changes in urine pH, a decrease in urine volume, and the presence of substances that promote or inhibit stone formation.Supersaturation of Urine: This is the...