1. Chapter 26, part 1
The Urinary System

2. Learning Objectives
Identify the components and functions of the urinary system
Describe the location and structural features of the kidneys
Describe the structure of a nephron, and outline the processes involved in the formation of urine
Describe the normal characteristics, composition, and solute concentrations of a representative urine sample

3. Learning Objectives
List and describe the factors that influence filtration pressure and the rate of filtrate formation
Identify the types of transport mechanisms found along the nephron
Describe how antidiuretic hormone and aldosterone levels influence the volume and concentration of urine

4. SECTION 26-1 An Overview of the Urinary System

5. Functions of the urinary system
Excretion
The removal of organic waste products from body fluids
Elimination
The discharge of waste products into the environment
Homeostatic regulation of blood plasma
Regulating blood volume and pressure
Regulating plasma ion concentrations
Stabilizing blood pH
Conserving nutrients

6. Urinary system includes:
The kidneys
Produce urine
The ureters
The urinary bladder
Stores urine
The urethra

7. Figure 26.1 An introduction to the Urinary System

8. SECTION The Kidneys

9. The kidneys Left kidney extends slightly more superiorly than right
Both kidneys and adrenal glands are retroperitoneal
Hilus
Entry for renal artery and renal nerves
Exit for renal veins and ureter

10. Figure 26.2 The Position of the Kidneys
Figure 26.2a, b

11. Figure 26.3 The Urinary System in Gross Dissection

12. Sectional anatomy of the kidneys
Superficial outer cortex and inner medulla
The medulla consists of 6-18 renal pyramids
The cortex is composed of roughly 1.25 million nephrons
Major and minor calyces along with the pelvis drain urine to the ureters

13. Figure 26.4 The Structure of the Kidney
Figure 26.4a, b

14. Blood supply and innervation of the kidneys
Renal arteries branch repeated
Renal artery
Segmental artery
Interlobar artery
Arcuate artery
Interlobular artery
Afferent arterioles
Renal venules follow similar opposing pattern ending with renal veins

15. Figure 26.5 The Blood Supply to the Kidneys
Figure 26.5a, b

16. Figure 26.5 The Blood Supply to the Kidneys
Figure 26.5c, d

17. The nephron consists of a renal corpuscle and renal tubule
The renal corpuscle is composed of
Bowman’s capsule and the glomerulus
The renal tubule consists of
Proximal convoluted tubule (PCT)
Loop of Henle
Distal convoluted tubule (DCT)

18. Filtrate is produced at the renal corpuscle
Nephron empties tubular fluid into collecting system
Collecting ducts and papillary ducts

19. Figure 26.6 A Representative Nephron

20. Nephron functions include:
Production of filtrate
Reabsorption of organic nutrients
Reabsorption of water and ions
Secretion of waste products into tubular fluid

21. Two types of nephron Cortical nephrons ~85% of all nephrons
Located in the cortex
Juxtamedullary nephrons
Closer to renal medulla
Loops of Henle extend deep into renal pyramids

22. Figure 26.7 Cortical and Juxtamedullary Nephrons
Figure 26.7a

23. Figure 26.7 Cortical and Juxtamedullary Nephrons
Figure 26.7b, c