Urinary System Overview

Urinary System Overview

• The urinary system transports waste from the kidneys to the bladder.
• In women, the ovaries are near the kidneys.
• Kidneys filter blood and excrete waste.

Kidney Functions

• Removal of waste products
• Maintaining electrolyte balance
• Maintaining acid-base balance
• Regulating blood volume and pressure
• Activation of vitamin D
• Production of erythropoietin
• Production of other hormones.

Kidney Location

• Located in the upper part of the posterior abdominal wall.
• The right kidney is positioned at the level of T12 to L3.
• The left kidney is located at the level of T11 to L2.
• The left kidney is slightly higher than the right kidney.

Urinary System Organs

• Two kidneys
• Two ureters
• The urinary bladder
• The urethra

Bladder (Vesica Urinaria)

• Function: a reservoir for urine.
• Location: Posterior to the symphysis pubis (anterior to the uterus in females, anterior to the rectum in males)
• Capacity: Approximately 220 mL, can hold up to 500 mL.
• Position: Usually within the pelvis minor, but when full, can extend to the level of the umbilicus.

Ureters

• Channels that transport urine from the kidneys to the bladder.
• Approximately 25-30 cm long.
• Pass through the linea terminalis.
• Travel along the lateral wall of the pelvis.

Urethra

• In males, it is 15-20 cm long; in females, approximately 3-5 cm.
• Contains internal and external sphincter muscles.

Kidney Structure

• The hilum renale is a fissure on the medial surface of the kidney through which structures enter and exit.
• Approximately at the level of L1 vertebra.
• The hilum renale opens medially into a region called the sinus renalis.
• Within the sinus renalis, there are calices minores et majores, the pelvis renalis, blood vessels, nerves, and adipose tissue.
• Medulla renalis contains pyramidal structures with their bases oriented toward the cortex renalis.
• Cortex renalis comprises the outer one-third of the renal mass.
• Cortex renalis contains glomeruli and Bowman's capsules.

Blood Supply to the Kidneys

• Renal artery arises from the aorta abdominalis.
• Renal vein drains into the vena cava inferior.

Nephron

• The functional unit of the kidneys.
• Each kidney contains over 1 million nephrons.

Stages of Urine Formation

• Filtration: Passage of plasma fluid from the glomerulus into the glomerular capsule (120 mL/min).
• Reabsorption: Re-absorption of beneficial substances like water, glucose and electrolytes back into the bloodstream.
• Excretion: Process of transferring metabolic waste products to the tubules, becoming urine.

Parts of the Urethra (in males)

• Pars prostatica
• Pars membranacea
• Pars spongiosa

Explore the essential functions and anatomy of the urinary system in this quiz. Learn about the role of kidneys, bladder, and associated organs, as well as their locations in the body. Test your knowledge of how these components work together to maintain bodily functions.