Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Location—under back muscles, behind parietal peritoneum, just above waistline; right kidney usually a little lower than left (Figure 17-1)  Internal structure (Figure 17-2)  Cortex—outer layer of kidney substance  Medulla—inner portion of kidney  Pyramids—triangular divisions of medulla  Papilla—narrow, innermost end of pyramid  Pelvis—expansion of upper end of ureter; lies inside kidney  Calyces—divisions of renal pelvis Slide 2

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 3

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 4

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 5

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 6

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Microscopic structure—nephrons are microscopic units of kidneys; consist of (Figure 17-3):  Renal corpuscle ▪ Bowman’s capsule—the cup-shaped top ▪ Glomerulus—network of blood capillaries surrounded by Bowman’s capsule  Renal tubule ▪ Proximal convoluted tubule—first segment ▪ Loop of Henle—extension of proximal tubule; consists of descending limb, loop, and ascending limb ▪ Distal convoluted tubule—extension of ascending limb of loop of Henle ▪ Collecting tubule—straight extension of distal tubule Slide 7

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 8

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 9

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 10

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Functions  Excretes toxins and nitrogenous wastes  Regulates levels of many chemicals in blood  Maintains water balance  Helps regulate blood pressure via secretion of renin Slide 11

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Occurs by a series of three processes that take place in successive parts of nephron  Filtration—goes on continually in renal corpuscles; glomerular blood pressure causes water and dissolved substances to filter out of glomeruli into Bowman’s capsule; normal glomerular filtration rate 125 mL per minute  Reabsorption—movement of substances out of renal tubules into blood in peritubular capillaries; water, nutrients, and ions are reabsorbed; water is reabsorbed by osmosis from proximal tubules  Secretion—movement of substances into urine in the distal and collecting tubules from blood in peritubular capillaries; hydrogen ions, potassium ions, and certain drugs are secreted by active transport; ammonia is secreted by diffusion  Control of urine volume—mainly by posterior pituitary hormone’s ADH, which decreases it Slide 12

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 13

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Structure (Figure 17-6)—narrow, long tubes with expanded upper end (renal pelvis) located inside kidney and lined with mucous membrane  Function—drain urine from renal pelvis to urinary bladder Slide 14

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 15

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Structure (Figure 17-7)  Elastic muscular organ, capable of great expansion  Lined with mucous membrane arranged in rugae, as is stomach mucosa  Functions  Storage of urine before voiding  Voiding Slide 16

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 17

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 18

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Structure  Narrow tube from urinary bladder to exterior  Lined with mucous membrane  Opening of urethra to the exterior called urinary meatus  Functions  Passage of urine from bladder to exterior of the body  Passage of male reproductive fluid (semen) from the body Slide 19

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Passage of urine from body (also called urination or voiding)  Regulatory sphincters  Internal urethral sphincter (involuntary)  External urethral sphincter (voluntary)  Bladder wall permits storage of urine with little increase in pressure  Emptying reflex  Initiated by stretch reflex in bladder wall  Bladder wall contracts  Internal sphincter relaxes  External sphincter relaxes, and urination occurs Slide 20

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.  Urinary retention—urine produced but not voided  Urinary suppression—no urine produced but bladder is normal  Incontinence—urine is voided involuntarily  May be caused by spinal injury or stroke  Retention of urine may cause cystitis  Cystitis—bladder infection  Overactive bladder—need for frequent urination  Called interstitial cystitis  Amounts voided are small  Extreme urgency and pain are common Slide 21