1. Kidney - External Macro Anatomy

2. Kidney Anatomy
Cortex

3. Kidney - Internal Macro Anatomy
Column
Papillae
Base
Medulla

4. Nephron
Renal Tubule
Renal Corpuscle

5. Renal Corpuscle Renal corpuscle Site of fluid filtration 2 components
glomerulus
group of capillary loops
fed by afferent arteriole
removed by efferent arteriole
glomerular (Bowman's) capsule
double walled epithelial cup
outer wall (parietal layer) separated from inner wall (visceral layer) by capsular (Bowman's) space

6. Nephron Renal tubule - where filtered fluid passes from capsule
proximal convoluted tubule (PCT)
loop of Henle (nephron loop)
distal convoluted tubule (DCT)
short connecting tubules
collecting ducts
merge to papillary duct
then to minor calyx
30 pap ducts/papillae

7. Nephron Cortical vs. juxtamedullary nephrons
Name depends on length of LofH
15-20% have long loops and  reabsorptive capabilities

8. Renal Corpuscle Histology
Each nephron portion has distinctive features
Histology of Glomerular filter
Three layers of tissue
From inside to out prevents movement of progressively smaller particles

9. Renal Corpuscle Histology
Endothelium of glomerulus
Single layer of endothelium w/ fenestrations
Restricts RBC movement

10. Renal Corpuscle Histology
Basement membrane of glomerulus
Between endothelium and visceral layer of glom capsule
Prevents large protein movement

11. Renal Corpuscle Histology
Filtration slits in podocytes
Podocytes
specialized epithelium of visceral layer
footlike extensions w/ slits between extensions
Restrict medium-sized proteins

12. Renal Corpuscle Histology

13. Tubule Histology
In general, tubule is a single layer of epithelial cells on basement membrane
PCT
cuboidal w/ brush border of microvilli on apical border
 surface area for reabsorption

14. Tubule Histology Descending loop of Henle, beginning of ascending loop
simple squamous epithelium
only permeable to water
Remainder of ascending loop
cuboidal to low columnar epithelium
only permeable to ions

15. Tubule Histology
DCT, collecting ducts - cuboidal w/ some modifications in late DCT collecting ducts
principal cells
intercalated cells

16. Tubule Histology Juxtaglomerular apparatus (JGA)
Ascending LofH contacts afferent arteriole
Macula Densa
special cells in this area monitor Na+Cl- content in blood
able to work w/ JG cells
Juxtaglomerular (JG) cells
modified smooth muscle
secrete vasoconstrictors
Both work together to regulate BP

17. Renal Blood Supply Important in italics Renal artery
20-25% of resting CO
1200 ml/min
Segmental arteries
Interlobar arteries - through columns
Arcuate arteries
Interlobular arteries

18. Renal Blood Supply Important in Italics
Afferent arterioles - each renal corpuscle receives 1
Glomerular caps
Efferent arterioles - drain blood from glomerulus
Peritubular caps - around PCT and DCT
Vasa recta - long loop from efferent arteriole around LofH

19. Renal Blood Supply Important in italics Interlobular veins
Arcuate veins
Interlobar veins
Segmental veins
Renal veins - exits hilus

20. Renal Nerve Supply Nerves from renal plexus of SNS
Vasomotor nerves that accompany renal arteries and branches
What is the role of SNS stimulation on renal blood flow?
Fight or flight
Decrease flow

21. The Final Common Pathway
Ureter
extension of kidney pelvis
enter bladder medially from posterior
Histology - 3 layers
mucosa
mucous membrane w/ transitional epithelium
secrete mucous
muscularis - smooth
inner longitudinal
outer circular
serosa

22. The Final Common Pathway
Urinary bladder
hollow muscular organ
generally smaller in females due to uterus
retroperitoneally in pelvic cavity posteriorly to pelvic symphysis
freely movable
Structure - trigone

23. The Final Common Pathway
Histology
mucosa - mucous membrane of transitional epithelium and underlying lamina propria
muscularis
detrusor muscle 3 layers of inner longitudinal, mid circular, outer longitudinal
around opening to urethra
circular fibers form internal urethral sphincter
lower is external urethral sphincter - skeletal muscle for control
serosa - peritoneum

24. The Final Common Pathway

25. The Final Common Pathway
Urethra
small tube from floor of bladder to exterior of body
females fairly straight path out through vagina
males passes through the prostate gland
histology
female three coats
inner mucous, intermediate thin layer of spongy tissue w/ plexus of veins
outer muscular coat continuous w/ bladder
male two layers
inner mucous membrane
outer submucous tissue connects w/ structures that it passes