Urinary System Lecture Notes

Goals of the Chapter

• Name the essential organs of the urinary system, describe their locations and functions.
• Identify common pathological conditions.
• Understand how urinalysis is used as a diagnostic test.
• Define urinary system-related combining forms, prefixes, and suffixes.
• Understand clinical procedures, laboratory tests, and abbreviations related to the urinary system.

Nitrogenous Wastes

• Types: Urea, Creatinine, and Uric Acid.
• Purpose: Excreted from the body to get rid of waste.

Functions of the Kidneys

• Filtration: Filter nitrogenous waste to form urine. Approximately 200 quarts of blood filtered daily to form about 2 quarts of urine.
• Balance: Maintain proper balance of water, electrolytes (such as sodium and potassium), and acids.
• Hormones: Release hormones like renin (adjusts blood pressure) and erythropoietin (EPO, stimulates red blood cell production).
• Regulation: Adjust water and electrolytes for proper muscle and nerve function.

Organs of the Urinary System

• Male Urinary System: Two kidneys, two ureters, urinary bladder, and urethra.
• Female Urinary System: Similar to males but with shorter urethra.

Differences between Male and Female Systems

• Urethra Length: Longer in males, making females more prone to UTIs.
• Openings: Males have a common opening for urinary and reproductive systems; females have separate openings.

How Kidneys Produce Urine

• Blood Flow: Blood enters kidneys through renal arteries, and arterioles carry blood to capillaries.
• Filtration: Glomeruli filter blood, similar to a sieve.
• Nephrons: Approximately 1 million in each kidney cortex.
• Survival: Possible with one kidney, which can grow to compensate.

Urine Formation Steps

1. Glomerular Filtration: Removes water, sugar, wastes, and salts.
2. Tubular Reabsorption: Body reabsorbs necessary substances.
3. Tubular Secretion: Secretes acids, potassium, and drugs.

Fun Fact

• Commonly excreted drugs include antidepressants, pain medications, and Viagra.

Urine Color and Health

• Clear: Possibly drinking too much water.
• Pale Straw/Light Lemonade: Normal.
• Dark Yellow: Dehydration risk.
• Amber/Honey: Severe dehydration or liver disease.
• Pink/Red: Possible food causes or blood in urine.
• Orange/Blue/Green: May indicate medical conditions or dietary influences.

Terminology

• Arteriole: Small artery.
• Calyx: Cup-like region of renal pelvis.
• Catheter: Tube for fluid management.
• Creatinine: Nitrogenous waste in urine.
• Electrolytes: Elements like sodium and potassium carrying electrical charge.
• Erythropoietin (EPO): Hormone for red blood cell production.

Additional Terms

• Glomerulus: Filters blood in the kidneys.
• Meatus: Opening or canal.
• Medulla: Inner region of an organ.
• Nephron: Kidney's functional unit.
• Renal Tubules: Where urine forms after filtration.

Important Definitions

• Ureter: Tube from kidneys to bladder.
• Urethra: Tube from bladder to outside.
• Urinary Bladder: Stores urine.
• Urination/Void: Process of expelling urine.

Misconceptions

• Peeing on jellyfish stings is ineffective due to low urea concentration.

This lecture focused on terminology associated with the urinary system and provided foundational knowledge necessary for understanding medical terminology related to this organ system.