1. Chapter 19, part A
The Kidneys

2. About this Chapter Anatomy of the excretory system
How the kidney is organized
How the nephron works to filter blood, recycle, secrete, and excrete
How filtration is regulated
Urination reflex

3. Kidney Functions: Overview
Homeostatic regulation: ECF volume, osmolarity, ion & pH balance
Excretion: Metabolic wastes & foreign molecules
Regulating hormones & enzymes

4. Kidney Functions: Overview
Figure 19-3: The excretion of a substance depends on the amount that was filtered, reabsorbed, and secreted

5. Excretory System: Anatomy Review
Kidney
Cortex
Medulla
Pelvis
Nephrons
Ureter
Bladder
Urethra
Figure 19-1: Anatomy Summary: The Urinary System

6. Nephron Functions: Overview
Filtration, reabsorption, secretion & excretion
PLAY
Animation: Urinary System: Glomerular Filtration

7. Nephron Functions: Overview
Figure 19-2: Filtration, reabsorption, secretion, and excretion

8. Glomerulus & Bowman's Capsule: Blood Filtration
Capillaries
Podocytes
Mesanglial cells
Bulk flow
Solutes
Water
(Few proteins)
(Not cells)

9. Glomerulus & Bowman's Capsule: Blood Filtration
Figure 19-4: Structure of the renal corpuscle

10. Glomerular Flow Rate (GFR)
Capillary
Hydrostatic pressure
Colloidal
Capsule pressure
Back pressure
Net Filtration p
GFR  180L/day (about 1% is excreted)
Figure 19-6: Filtration pressure in the renal corpuscle

11. Glomerular Flow Rate (GFR)
Figure 19-5: The filtration fraction

12. Regulation of GFR Autoregulation Myogenic stretch
Tubuloglomerular feedback
Macula densa
J G cells
ANS-Sympathetic
Arteriole vasoconstriction
Hormones/paracrines
Angiotensin II
Prostaglandins

13. Figure 19-9: The juxtaglomerular apparatus
Regulation of GFR
Figure 19-9: The juxtaglomerular apparatus