Urinary Smooth, collapsible, muscular sac stores urine Figure 15.6 Slide 15.21a
Urinary Bladder Wall Walls are and folded in an empty bladder Bladder can significantly without increasing internal pressure Slide 15.22
Thin-walled tube that carries urine from the to the of the body by peristalsis Release of urine is controlled by two sphincters Internal urethral sphincter ( ) External urethral sphincter ( ) Slide 15.23
Urethra Gender Differences Length Females (1 inch) Males (8 inches) Location Females along wall of the Males through the and Slide 15.24a
Urethra Differences Function Females carries urine Males carries urine and is a passageway for cells Slide 15.24b
(Voiding) Both sphincter muscles must to allow voiding The internal urethral sphincter is relaxed after of the bladder The external urethral sphincter must be relaxed Slide 15.25
Maintaining Water Balance Normal amount of water in the human body Young adult females % Young adult males % Babies % Old age % Water is necessary for many body functions and levels must be maintained Slide 15.26
Distribution of Body Fluid Intracellular fluid (inside cells) Extracellular fluid (outside cells) Interstitial fluid Blood plasma Figure 15.7 Slide 15.27
Maintaining Water Balance Water must equal water Sources for water intake Ingested foods and fluids Water produced from metabolic processes Sources for water output out of the lungs Lost in Leaves the body in the production Slide 15.29
Maintaining Water Balance urine is produced if water intake is excessive Less urine ( ) is produced if large amounts of water are lost Proper concentrations of various must be present Slide 15.30
Regulation of Water and Electrolyte Reabsorption Regulation is primarily by hormone (ADH) prevents excessive water loss in urine regulates sodium ion content of extracellular fluid Slide 15.31
Maintaining Water and Electrolyte Balance Figure 15.9 Slide 15.32
Maintaining Acid-Base Balance in Blood Blood ph must remain between and to maintain homeostasis ph above 7.45 ph below 7.35 Most ions originate as byproducts of cellular metabolism Slide 15.33a
Maintaining Acid-Base Balance in Blood Most acid-base balance is maintained by the Other acid-base controlling systems buffers Slide 15.33b
Renal Mechanisms of Acid-Base Balance Excrete bicarbonate ions if needed Conserve or generate new bicarbonate ions if needed Urine ph varies from to Slide 15.37
Developmental Aspects of the Urinary System Functional kidneys are developed by the month Urinary system of a newborn Bladder is small Urine cannot be Slide 15.38a
Developmental Aspects of the Urinary System Control of the voluntary urethral sphincter does not start until age months Urinary are the only common problems before old age Slide 15.38b
Aging and the Urinary System There is a progressive decline in urinary function The bladder with aging need to go more frequently Urinary retention is common in the inability to hold urine Slide 15.39
Homeostatic imbalances in urinary system Renal calculi most are calcium oxalate or triple phosphate Excess calcium intake (milk etc) can cause Excess phosphates (soda) If small enough can be passed, but treatment may involve using sound waves to break up the stone
UTI Urinary tract infections usually from bacteria entering from the digestive system (poor toileting practices) Cloudy urine with possible blood, pain when urinating, urge to go frequently, fever.