Anatomy of the Urinary System Notes Kidneys Function

Anatomy of the Urinary System Notes

Kidneys: Function • • • Keep body free of impurities Maintain water & chemical balance Oversees composition of electrolytes Regulate blood pressure Secretes hormones

Kidneys • Located in posterior abdomen • Suspended by connective tissue • Functional Unit: – Nephron – System of tubes and filters

The Nephron

Urine Formation • Filtration – blood from renal arteries enters nephron – Small molecules pass through filter (water, glucose, aa, urea) – Large molecules do not pass (blood cells, proteins) • Reabsorption – water and nutrients are reabsorbed back into blood stream • Secretion – drugs and other wastes are secreted into tubes – Urine funneled into ureters

Urine • Urochrome – pigment produced from breakdown of bile – Hydration – Hematuria – blood in urine • p. H of 6 (affected by disease and diet)

Ureters • Tubes that transport urine from kidneys to bladder

Bladder • Stores urine until it is eliminated • Smooth muscle – Stretches like a balloon (hold up to 600 ml of urine) – Muscles relax when bladder is filling / contract during urination

Urethra • Muscular tube connecting bladder to exterior • Male – 8 inches • Female – 1. 5 inches – More susceptible to infection