1. Filtration Barrier Lamina rara externa Lamina densa
Lamina rara interna

3. Glomerular Filtration
Filtering of blood in the renal corpuscle
Glomerular filtrate – fluid that seeps from the glomerular capillaries into the Bowman’s space

5. Renal Tubule Proximal convoluted tubule Loop of Henle
Thick descending limb
Thin descending and ascending limbs
Thick ascending limb
Distal convoluted tubule
Collecting tubules and ducts

7. Proximal Convoluted Tubule Distal Convoluted Tubule
Renal Tubule
Proximal Convoluted Tubule
Loop of Henle
Distal Convoluted Tubule
Epithelium
Simple cuboidal
Thick descending limb: simple cuboidal
Thin limb: simple squamous
Thick ascending: simple cuboidal
Function
Reabsorb 70-80% of H2O and sodium
Reabsorb glucose, AA, chloride
H2O reabsorption except:
Thick ascending: impermeable to water, NaCl reabsorption
Secretes potassium and hydrogen
Small H2O and Na reabsorption

8. Types of Nephrons Short-looped (cortical) - majority
Renal corpuscles located in outer portions of cortex
Short Henle’s loop (no thin ascending limb)
Long-looped (juxtamedullary)
Renal corpuscles are near the corticomedullary junction
Long Henle’s loop (go deep into medulla, have thin ascending limb)

10. Juxtaglomerular Apparatus
Microscopic structure in the kidney which regulates the function of each nephron
Found between the vascular pole of the renal corpuscle and the returning DCT of the same nephron
Function: regulates filtrate formation and systemic BP

13. Juxtaglomerular Apparatus
3 cells:
Juxtaglomerular cells
Mesangial cells
Macula densa cells - area of closely packed specialized columnar cells lining the wall of the distal tubule
Sense changes in solute concentration and flow rate of filtrate

15. BLADDER AND URINARY PASSAGES
Renal calyces
Renal pelvis
Ureter
Urinary bladder
Same histologic structure
Walls of ureter becoming gradually thicker as proximity to the bladder increases

16. BLADDER AND URINARY PASSAGES
Function:
Store the urine formed in the kidneys and conduct it to the exterior

17. BLADDER AND URINARY PASSAGES
Mucosa:
Transitional epithelium
Lamina propria: loose to dense CT
Muscular layer – OCIL
Adventitia or serosa
Only upper part of bladder covered by peritoneum

23. URETHRA Terminal portion of the urinary system Function:
Passageway for urine
Males: passageway for urine and sperms

24. Male Urethra 20 cm in length 3 segments:
Prostatic urethra
Membranous urethra
Spongy urethra (penile, cavernous)
Terminates in the external urethral orifice (meatus)

26. Male Urethra Prostatic Membranous Penile Length and location 3-4 cm
Traverses the prostate gland
1 cm
Traverses the sphincter urethrae muscle
15 cm
Traverses the penis
Lining epithelium
Transitional
Pseudostratified columnar
EUM: Stratified squamous non-keratinized
Glands
Urethral glands of Littre (lamina propria)
Bulbourethral glands of Cowper (embedded in the sphincter urethrae muscle)
Bulbourethral glands of Cowper

30. Female Urethra Shorter (4 cm)
Closely attached to anterior wall of vagina
Opens directly in front of the vaginal opening on the vestibule of the external genitalia

31. Female Urethra

32. Female Urethra
Mucosa
Transitional → stratified squamous non-keratinized
Lamina propria: loose CT, mucus-secreting urethral glands
Muscular layer: circularly arranged smooth muscle cells

34. Female Urethra
Distal segment is surrounded by circularly-arranged striated (voluntary) muscle fibers (sphincter urethrae muscle – external sphincter)