1. Urinary System:
Outcome: I can describe the specific filtration process kidneys use for blood.
Drill:
What are the four main structures/organs in the urinary system?

2. Nephron Collecting System Figure 24.4 1 – 2 2 4 Proximal Convoluted
Overview of a nephron and the collecting system
Slide 1
Nephron
Collecting System 2 4
Proximal
Convoluted
Tubule
Distal
Convoluted
Tubule
Renal
tubule 1
Renal
Corpuscle
Efferent arteriole 5
Collecting Duct
Afferent arteriole
Glomerular capsule
Descending
limb of
loop begins
Ascending
limb of
loop ends
Capsular space
Glomerulus 3
Ascending
limb
Nephron Loop 6
Papillary Duct
KEY
Filtrate
Water reabsorption
Variable water reabsorption
Solute reabsorption or secretion
Descending
limb
Variable solute reabsorption
or secretion
© Pearson Education, Inc.
Figure 24.4 1 – 2

3. Renal cortex Cortical nephron Juxtamedullary nephron Renal medulla
Types of nephrons and their location
Renal cortex
Cortical
nephron
Juxtamedullary
nephron
Renal
medulla
Minor calyx
© Pearson Education, Inc.
© Pearson Education, Inc.
Figure 24.3 3

4. Segments of a Nephron Nephron components Two components
Renal corpuscle
Blood pressure forces water and solutes out of the glomerular capillaries in a process called filtration
Produces filtrate (protein-free solution, similar to blood plasma)
Renal tubule
Tubular passageway
Receives filtrate and modifies it to create urine
© 2015 Pearson Education, Inc.

5. Segments of a Nephron Nephron segments Renal corpuscle
Glomerular capsule (cup-shaped chamber)
Capillary network (glomerulus)
Proximal convoluted tubule (PCT)
Reabsorbs nutrients from the filtrate (now called tubular fluid)
© 2015 Pearson Education, Inc.

6. Segments of a Nephron Nephron segments (continued)
Nephron loop (Loop of Henle)
Establishes osmotic gradient for water reabsorption
Each limb contains a thin segment and a thick segment
Distal convoluted tubule (DCT)
Adjusts tubular fluid composition by reabsorption and secretion
© 2015 Pearson Education, Inc.

7. Nephron Figure 24.4 1 2 4 Proximal Convoluted Tubule Distal Convoluted
Parts of a nephron
Nephron 2 4
Proximal
Convoluted
Tubule
Distal
Convoluted
Tubule
Renal
tubule 1
Renal
Corpuscle
Efferent arteriole
Afferent arteriole
Glomerular capsule
Descending
limb of
loop begins
Ascending
limb of
loop ends
Capsular space
Glomerulus 3
Ascending
limb
Nephron Loop
KEY
Filtrate
Water reabsorption
Variable water reabsorption
Solute reabsorption or secretion
Descending
limb
Variable solute reabsorption
or secretion
© Pearson Education, Inc.
© Pearson Education, Inc.
Figure 24.4 1

8. Circulation Patterns in the Kidney
Blood flow around a nephron
Afferent arteriole
Supplies blood to each individual nephron
Glomerulus (FILTRATION OCCURS HERE)
Efferent arteriole
Carries blood from the glomerulus to the peritubular capillaries
Peritubular capillaries (in Cortical Nephron)
Vasa Recta (in Juxtmedullary Nephron)
Surround the entire renal tubule
Collect water and solutes absorbed by the nephron
Deliver other solutes to the nephron for secretion
Drain into cortical radiate veins
© 2015 Pearson Education, Inc.

9. Glomerular capsule Capsular space Initial segment of renal tubule
Cross-sectional view of the visceral layer of the glomerular capsule
Glomerular capsule
Capsular space
Initial segment
of renal tubule
Efferent
arteriole
DCT
Juxtaglomerular
complex
Parietal layer
Visceral layer
Visceral layer
Afferent
arteriole
Glomerular
endothelial cell
Mesangial
cells
Filtration slits
RBC
Pedicels
Podocyte
Capsular space
© Pearson Education, Inc.
© Pearson Education, Inc.
Figure 24.8 1 – 2

10. Peritubular capillaries
Peritubular capillaries in a cortical nephron
Glomerulus in
renal corpuscle
Peritubular capillaries
Efferent arteriole
Afferent arteriole
To the cortical
radiate vein
© Pearson Education, Inc.
© Pearson Education, Inc.
Figure 24.5 2

11. Peritubular capillaries
Vasa recta in a juxtamedullary nephron
Peritubular capillaries
Efferent arteriole
Afferent arteriole
To cortical
radiate vein
Capillaries of
the vasa recta
© Pearson Education, Inc.
© Pearson Education, Inc.
Figure 24.5 3

12. Urine storage and elimination
Locations of filtration, reabsorption, and secretion in the nephron and collecting system
Proximal convoluted
tubule (PCT)
Distal convoluted
tubule (DCT)
Glomerulus
KEY
Filtration
Water reabsorption
Variable water
reabsorption
Glomerular
capsule
Collecting duct
Solute reabsorption
Variable solute
reabsorption or
secretion
Nephron loop
© Pearson Education, Inc.
© Pearson Education, Inc.
Urine storage and elimination
Figure 24.7 1

13. Glomerular Filtration Rate
Glomerular filtration rate (GFR)
Amount of filtrate produced by the kidneys each minute
Each kidney has ~6 m2 (64 sq. ft.) of filtration surface
GFR averages 125 mL/min (180 L/day)
~99 percent is reabsorbed
© 2015 Pearson Education, Inc.

14. Urinary System:
Exit Ticket:
Describe the pathway of blood flow into the kidney. What arteries are being pass through (in order)?