Urinary System Overview

Urinary System Overview

• The urinary system's function is to filter blood and eliminate waste.
• It comprises six major organs: two kidneys, two ureters, the urinary bladder, and the urethra.

Kidneys

• Located in the posterior abdominal wall, on either side of the vertebral column.
• The right kidney is positioned at the level of T12 to L3, and the left kidney at the level of T11 to L2.
• The left kidney is slightly higher than the right.
• Kidneys filter blood and excrete waste products (forming urine).
• Kidneys maintain blood volume and pressure, electrolytes, and acid-base balance.

Ureters

• The ureters transport urine from the kidneys to the bladder.
• Approximately 25-30 cm long.
• Ureters pass through the linea terminalis, entering the pelvis minor.
• Ureters travel along the pelvis's lateral wall to reach the bladder.

Bladder

• Functions as a urine reservoir.
• Located posterior to the symphysis pubis (anterior to the uterus in females and anterior to the rectum in males).
• Normal capacity is ~220 mL, but can hold up to 500 mL.
• An empty bladder lies within the pelvis minor; a full bladder extends to the level of the umbilicus.

Urethra

• Transports urine from the bladder to the outside of the body.
• In males, it is ~20 cm long, while in females, it's ~3-5 cm long.
• Urethra has internal and external sphincter muscles to control urine flow.

Urinary System Component Details

• Calyx minor: Urine-collecting structures.
• Calyx major: Structures that collect urine from minor calyxes.
• Renal pelvis: Urine-collecting funnel within the kidney.
• Urinary bladder: Hollow muscular organ storing urine.
• Ureters: Urine-transporting tubes.
• Urethra: Urine-expelling tube.
• Renal artery: Supplies blood to the kidneys.
• Renal vein: Drains blood from the kidneys.
• Afferent arteriole: Carries blood to the glomerulus.
• Efferent arteriole: Carries blood away from the glomerulus.
• Glomerulus: Network of capillaries within the nephron, where filtration occurs.
• Nephron: Basic functional unit of the kidney.
• Glomerular capsule (Bowman's capsule): Cup-shaped structure surrounding the glomerulus.
• Loop of Henle: Part of the nephron, crucial for water reabsorption.
• Collecting duct: Receives urine from nephrons.

Additional Information

• Women are more prone to urinary tract infections as the urethra is shorter and closer to the anus.
• Males have a longer urethra, offering less frequency of urinary infections.
• Kidneys are responsible for regulating blood pressure.
• Kidneys play a role in blood volume and electrolyte control.

This quiz covers key concepts of the urinary system, including the roles and locations of the kidneys, ureters, and bladder. Test your knowledge on how these organs work together to filter blood and eliminate waste. Understand the anatomical relationships and physiological functions of this critical system.