Kidneys: Functions, Disorders, and Anatomy

Study Notes

Kidneys

Kidneys are two small organs located near the lower back of your abdomen. They play a crucial role in maintaining homeostasis, which is the body's balance of bodily fluids, electrolytes, acids and bases, blood pressure, and red blood cells. They perform various vital functions that contribute to the health of your body. Let's explore these functions and disorders associated with kidneys.

Functions

The primary roles of kidneys are:

Filtration: Kidneys filter waste products and excess fluids from the blood, creating urine.
Reabsorption: The filtrate is processed by the tubules, which absorb essential nutrients like glucose and amino acids back into the bloodstream.
Secretion: In addition to reabsorption, some substances are actively secreted into the filtrate, such as hydrogen ions, which help maintain the acid balance in the blood.

Excretory System & Renal System Disorders

Renal system disorders include various conditions affecting the kidneys, including:

Chronic Kidney Disease (CKD): Caused by gradual loss of kidney function over time, leading to decreased waste removal and difficulty maintaining fluid and electrolyte balances.
Acute Kidney Injury (AKI): Sudden damage to the kidneys, often due to infections, injury, or toxic chemicals.
Renal Cysts: Fluid-filled sacs that develop in the kidneys, often benign but can be cancerous.
Kidney Stones: Solid mineral deposits that form in the kidney and can obstruct the flow of urine.
End-Stage Kidney Disease (ESKD): Complete loss of kidney function that requires dialysis or kidney transplantation.

Anatomy

The kidney is divided into an outer cortex and an inner medulla, with numerous nephrons, the functional units of the kidney. Each nephron consists of a renal corpuscle, a proximal convoluted tubule, a loop of Henle, and a distal convoluted tubule.

Scenario-Based

Consider a scenario where a patient with kidney failure requires dialysis, a life-saving treatment for removing waste from the blood when kidneys can't do so naturally. Dialysis allows the patient to survive, but it doesn't replace all the functions of a kidney. The patient must be closely monitored and managed to ensure the best possible outcome.