The Urinary System- Chapter 16

1. 1 The Urinary System- Chapter 16 Organs that make up the Urinary System Structure and Function Involuntary & Voluntary Components Health Problems

2. 2 Definitions Urology- the branch of medicine that treats male and female urinary systems as well as the male reproductive system. Nephrology- the scientific study of anatomy, physiology, and pathology of the kidney.

3. 3 Major Functions of the Urinary System Filter waste and excess material from the blood. Regulate blood volume and composition. Help regulate blood pressure. Store urine. Discharge urine.

4. 4 Urinary Organs

5. 5 Kidney Anatomy Kidneys Positioned just below the diaphragm in depressions against the deep muscles of the back. Bean-shaped and reddish brown in color. 4-5 inches in length and 2-3 inches wide. The Kidney contains three major regions Renal cortex. Renal medulla. Renal pelvis.

6. Figure: 16-04a Title: Structure of the kidney. Caption: (a) The blood vessels and three protective outer layers of the kidney. Figure: 16-04a Title: Structure of the kidney. Caption: (a) The blood vessels and three protective outer layers of the kidney.

7. Figure: 16-04bc Title: Structure of the kidney. Caption: (b) The basic internal structure of the kidney. (c) The location of nephrons within these regions is also shown. Figure: 16-04bc Title: Structure of the kidney. Caption: (b) The basic internal structure of the kidney. (c) The location of nephrons within these regions is also shown.

8. 8 The kidney consists of 1 million nephrons Nephrons- the functional unit of the kidney. Nephrons form urine. Urine is 95% water. Urine is 5% salts, urea (the primary nitrogenous waste), uric acid, ammonium ions, and creatinine (nitrogenous waste). Nephrons consists of 2 parts and capillary network that surrounds them. Renal Corpuscle. Renal tubule.

9. Figure: 16-05c Title: Structure of the nephron. Caption: (c) A nephron and its blood supply.Figure: 16-05c Title: Structure of the nephron. Caption: (c) A nephron and its blood supply.

10. Figure: 16-05b Title: Structure of the nephron. Caption: (b) Simplified view of a nephron, showing the basic structural components but not the associated capillaries.Figure: 16-05b Title: Structure of the nephron. Caption: (b) Simplified view of a nephron, showing the basic structural components but not the associated capillaries.

11. 11 Renal Corpuscle- part 1 of the Nephron Renal Corpuscle- site where fluid (blood) is filtered. Water, glucose, amino acids, urea, uric acid, and salts move from the glomerulus to the renal tubules. Glomerulus- a cluster of capillaries. Bowman�s Capsule- cuplike structure that surrounds the glomerulus.

12. Figure: 16-05d Title: Structure of the nephron. Caption: (d) The renal corpuscle, where blood is filtered.Figure: 16-05d Title: Structure of the nephron. Caption: (d) The renal corpuscle, where blood is filtered.

13. 13 Renal Tubules- part 2 of the Nephron Renal Tubule- site of reabsorption and secretion. Proximal convoluted tubule Water, glucose, amino acids, and salts are reabsorbed into the capillary network at this site. Loop of Henle- water and salts are reabsorbed into the capillary network at this site. Distal convoluted tubule Water and salts are further reabsorbed into the capillary network. Drugs and hydrogen ions are secreted from the capillary network into the renal tubule.

14. Figure: 16-05b Title: Structure of the nephron. Caption: (b) Simplified view of a nephron, showing the basic structural components but not the associated capillaries.Figure: 16-05b Title: Structure of the nephron. Caption: (b) Simplified view of a nephron, showing the basic structural components but not the associated capillaries.

15. 15 3 Functions of Nephrons 1) Glomerular Filtration 2) Tubular Reabsorption 3) Tubular Secretion

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18. 18 Urinary Bladder Anatomy Hollow muscular organ. Situated at the base of the pelvic cavity. Capacity average= 700-800ml. Smaller in females because the uterus occupies the space just superior to the bladder. Rugae- folds, are present. Function- to store urine.

19. 19 Urination The bladder fills with urine. Nerve impulses are sent to the spinal cord and then the brain. Motor nerve impulses are returned and cause the bladder to contract and the sphincters to open.

20. 20 Maintaining Water Balance- increasing water concentration in the blood Reabsorption of Water- 48 gallons of filtrate enters the renal tubules each day, 47 gallons of that is returned to the blood. Antidiuretic hormone (ADH) and Aldosterone cause water to be reabsorbed into the capillary network.

21. 21 Diuretics- decreasing water concentration in the blood. Diuretics- chemicals that increase the flow of urine. Alcohol- inhibits the secretion of ADH (antidiuretic hormone). Caffeine- increases glomerular filtration rate and decreases reabsorption of sodium.

22. 22 Maintaining Salt Balance Reabsorption of Salt- usually more than 99% of the sodium filtered in the glomerulus is returned to the blood. Atrial natriuretic hormone (ANH)- a hormone secreted by the heart atria that promotes sodium excretion in the urine. Aldosterone- a hormone secreted by the adrenal glands that promotes sodium absorption.

23. 23 Maintaining Acid-Base Balance To maintain normal blood pH, bicarbonate ions (basic) are reabsorbed by the capillary network and hydrogen ions (acidic) are excreted as needed into the proximal distal tubule.

24. 24 Problems with Kidney Function Many types of illness cause progressive renal disease and ultimate renal failure. Diabetes. Hypertension. Inherited conditions. Treatment of renal failure can include hemodialysis and kidney replacement.

25. 25 Dialysis- diffusion of dissolved molecules through a semipermeable membrane. Fig. 9.11aFig. 9.11a

26. 26 Review Overview of the Urinary System Functions of the Urinary System Urination Kidney Structure Nephrons Urine Formation Maintaining Water-Salt Balance Reabsorption of Water Reabsorption of Salt Kidney Problems