1. Urinary System chapter 15
Kidney
Cortex
Renal artery
Renal vein
Nephrons
Aorta
Cortex
Inferior vena cava
Medulla
Renal pelvis
Medulla
Collecting duct
Ureter
Bladder
Ureter
Urethra
a) The components of the urinary system.
b) Internal structure of the kidney.
c) The cortex and medulla of the kidney are composed of numerous nephrons.
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Animation—The Urinary System
Figure 15.2

2. Functions of Renal Organs
Table 15.2

3. Organs of the Urinary System
Kidneys
Cortex
Renal Medulla
Renal Pelvis

4. Urinary System Figure 15.2 Kidney Cortex Renal artery Renal vein
Nephrons
Aorta
Cortex
Inferior vena cava
Medulla
Renal pelvis
Medulla
Collecting duct
Ureter
Bladder
Ureter
Urethra
a) The components of the urinary system.
b) Internal structure of the kidney.
c) The cortex and medulla of the kidney are composed of numerous nephrons.
Figure 15.2

5. Organs of the Urinary System
Urinary bladder
Rectum
Internal urethral sphincter
Prostate gland
Uterus
Vagina
External urethral sphincter
Penis
Rectum
Urethra
Testis
a) The male
b) The female
Figure 15.3

6. Tubular and Vascular Nephron Components
Figure 15.5

7. Nephrons: Produce Urine
Bowman’s capsule/Glomerular capsule and Tubules
Function
Filter fluid and reabsorb needed substances
Structures
Glomerular capsule
Proximal tubule
Loop of Henle
Distal tubule
Collecting duct

8. Nephrons: Produce Urine
Blood vessels associated with tubules
Arterioles
Afferent (toward glomerular capsule)
Efferent (away from capsule)
Capillaries
Glomerular
Peritubular
Vasa recta

9. Formation of Urine
Figure 15.6

10. Formation of Urine: Glomerular Filtration
Filters fluid from capillaries into glomerular capsule
Rate of filtration
Resting rate under local chemical control
Stress causes sympathetic nervous system to reduce blood flow to kidneys

11. Formation of Urine: Tubular Reabsorption
Tubular reabsorption returns water and needed solutes to blood capillaries
Sodium moved by active transport from tubule cells to interstitial fluid and diffuses to capillaries
Chloride passively accompanies sodium (balanced charge)
Water reabsorbed with salts
Movement of sodium creates energy to transport glucose and amino acids into renal tubule then diffuses to the interstitial fluid

12. Tubular Secretion
Tubular secretion removes other substances from blood
Purpose
Regulation of chemical levels in body
Excretion of harmful chemicals
Substances secreted
Penicillin, cocaine, marijuana, pesticides, preservatives, hydrogen ions, ammonium, potassium

13. Concentration or Dilution of Urine: ADH
Dilute urine
Excreting excess water
Mechanism
Cycling of NaCl and urea create a concentration gradient in the medulla that allows water to diffuse from the renal tubules into the interstitial fluid and then into the blood capillaries

14. Formation of Dilute Urine
Figure 15.10

15. Concentration or Dilution of Urine: ADH
Concentrated urine
Conserving water
Mechanism
Countercurrent exchange
Increased ADH causes increased permeability to the collecting tubules and increased conservation of water

16. Formation of Concentrated Urine
Figure 15.11

17. Urination Micturition reflex Internal urethral sphincter Smooth muscle
External urethral sphincter
Skeletal muscle

18. Kidney’s Role in Homeostasis
Maintains water balance
Adjusts blood volume and blood pressure
Aldosterone, renin, ANH help maintain salt balance in order to control blood volume
Maintains acid–base balance and blood pH
Regulates red blood cell production via erythropoietin
Activates an inactive form of vitamin D

19. Kidney’s Role in Homeostasis
Figure 15.13

20. Kidney’s Role in Homeostasis
Figure 15.15

21. Disorders of the Urinary System
Kidney stones
Crystallized minerals
Block urine flow
Urinary tract infections (UTI)
Bacteria

22. Disorders of the Urinary System
Acute and chronic renal failure
Therapies
Dialysis
Kidney transplant