Human Biology: Excretory System Overview

The excretory system removes excess and waste products to maintain ______.

Each kidney contains about a million ______, which filter blood and remove wastes.

The ______ is a hollow organ that stores urine in the lower abdomen.

Urine is carried from the kidneys to the bladder through the ______.

Holding urine too long can lead to ______ damage or increased pressure.

Excretory System Overview

The excretory system removes excess and waste products to maintain homeostasis.
Waste is eliminated as urine, sweat, or feces.

Kidneys

Filter blood, remove waste, and produce urine.
Contains about one million nephrons per kidney.
Nephrons filter blood (glomerulus) and remove wastes (tubule).
Regulate blood pressure and maintain blood composition.

Ureters

Tubes carrying urine from the kidneys to the bladder.
Have upper and lower sections in the abdomen and pelvis, respectively.

Bladder

Hollow, expandable organ in the lower abdomen that stores urine.
Contracts to release urine through the urethra.

Urethra

Tube allowing urine to exit the body.
Bladder muscles tighten, and sphincter muscles relax for urination.

Risks of Holding Urine Too Long

Bladder strain: Overstretched muscles weaken bladder function.
UTIs: Prolonged urine retention promotes bacterial growth.
Bladder or kidney damage: Increased pressure can cause kidney stones or infections.
Urinary retention: Weak bladder muscles can lead to incomplete emptying.

Test your knowledge on the excretory system, including the roles of kidneys, ureters, bladder, and urethra in waste removal and homeostasis. Understand the processes involved in urine production and the risks associated with urine retention.