3.4.1 Review Urinary System

Urinary System Kidney Ureter Bladder Urethra Also notice….. Renal Vein Renal Artery

Functions of the Urinary System & Kidneys Elimination of waste products Nitrogenous wastes Toxins Drugs Regulate aspects of homeostasis Water balance Electrolytes Acid-base balance in the blood Blood pressure—release hormones to control BP Hormones produced regulates Red blood cell production Activation of vitamin D

Kidneys Bean- Shaped Near the middle of the back, just below the rib cage, one on each side of the spine. The right kidney is slightly lower than the left Attached to ureters, renal blood vessels, and nerves at renal hilus Function-see previous slide

Ureters Slender tubes attaching the kidney to the bladder Continuous with the renal pelvis Enter the posterior aspect of the bladder Peristalsis aids gravity in urine transport Transports urine from kidneys to bladder

The Bladder Function: Temporarily stores urine Made of transitional epithelium Multiple layers of tissue Cuboidal in shape when bladder is empty Stretched and flattened with bladder is full.

Urethra Thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis Release of urine is controlled by two sphincters Internal urethral sphincter (involuntary) External urethral sphincter (voluntary) Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Urethra Gender Differences Length Females – 3–4 cm (1 inch) Males – 20 cm (8 inches) Location Females – along wall of the vagina Males – through the prostate and penis Function Females – only carries urine Males – carries urine and is a passageway for sperm cells Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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