What Is the Urinary System? Structure, and Functions
Learn what the urinary system is, what structures it includes, how it filters blood and removes waste, and the key terms used to describe the kidneys, bladder, and urinary tract.
Urinary System: Structure, Function, and Key Terms
The urinary system is the body’s filtering and waste-removal system. It is made up of the kidneys, ureters, bladder, and urethra, all of which work together to remove waste products and extra fluid from the blood. This process creates urine, which the body stores and then removes.
The urinary system also helps maintain the body’s balance of water, salts, and certain chemicals. Together, these structures support healthy body function by helping keep the internal environment stable.
What Does the Urinary System Do?
The urinary system performs several important functions that are necessary for health and survival.
Filtering Blood
The kidneys filter the blood to remove waste products, toxins, and extra water.
Making and Removing Urine
The urinary system turns liquid waste into urine, carries it through the urinary tract, stores it in the bladder, and removes it from the body.
Maintaining Balance
The urinary system helps balance water, salts, and acid-base levels in the body.
Main Components of the Urinary System
The urinary system includes several key structures.
Kidneys
The kidneys are two bean-shaped organs that filter blood and produce urine.
Ureters
The ureters are tubes that carry urine from the kidneys to the bladder.
Bladder
The bladder is a hollow muscular organ that stores urine until the body is ready to release it.
Urethra
The urethra is the tube that carries urine out of the body.
How the Urinary System Works
The urinary system works by filtering blood, producing urine, and moving that urine out of the body.
Filtration
Blood enters the kidneys, where useful substances are returned to the bloodstream and waste products are separated out.
Urine Transport and Storage
Urine moves from the kidneys through the ureters to the bladder, where it is stored.
Urination
When the bladder is full, signals from the nervous system help the body release urine through the urethra.
How the Urinary System Works: Step by Step
A simple example can help explain how the urinary system works.
- Blood enters the kidneys
- The kidneys filter waste and extra fluid from the blood
- Useful substances return to the bloodstream
- Urine forms in the kidneys
- Urine travels through the ureters to the bladder
- The bladder stores urine until it is full
- Urine leaves the body through the urethra
Important Urinary System Terms
Understanding these key terms can make the urinary system easier to study.
- Kidney: An organ that filters blood and makes urine
- Ureter: A tube that carries urine from a kidney to the bladder
- Bladder: The organ that stores urine
- Urethra: The tube that carries urine out of the body
- Urine: Liquid waste removed from the body
- Filtration: The process of separating waste from the blood
- Urination: The process of releasing urine from the body
Common Prefixes and Suffixes
Medical terminology related to the urinary system often includes specific prefixes and suffixes.
Prefixes
- Nephro-: Relating to the kidney
- Reno- or Renal-: Relating to the kidney
- Uro-: Relating to urine or the urinary tract
- Cysto-: Relating to the bladder
Suffixes
- -uria: Condition of the urine
- -itis: Inflammation
- -ectomy: Surgical removal
- -logy: Study of
Why the Urinary System Matters
The urinary system is essential because it removes waste products and extra fluid while helping the body maintain internal balance. Without it, harmful substances and fluid imbalances would build up in the body.
A clear understanding of the urinary system helps explain how the body filters blood, makes urine, and removes waste each day.