1. URINARY SYSTEM: I

2. URINARY SYSTEM: I  TO IDENTIFY THE COMPONENTS OF THE URINARY SYSTEM
 TO CHARACTERIZE THE GENERAL ORGANIZATION OF THE KIDNEY
 TO EXAMINE THE HISTOLOGICAL STRUCTURE OF THE NEPHRON AND THE COLLECTING DUCTS
kidney-02
 TO CORRELATE STRUCTURE OF VARIOUS COMPONENTS WITH FUNCTION

3. URINARY SYSTEM  KIDNEY  URETER  BLADDER  URETHRA
ANATOMICAL STRUCTURE AND BLOOD SUPPLY
- highly vascular (25% cardiac output)
- produces urine (water and elctrolytes, urea, uric acid, creatinine), initially an ultrafiltrate of the blood
 URETER
 BLADDER
 URETHRA

4. URINARY SYSTEM  KIDNEY 1) EXOCRINE PORTION 2) ENDOCRINE PORTION
- synthesis and secretion of erythropoietin (regulation of red blood cell formation)
- synthesis and secretion of renin (hormone necessary for control of blood pressure and blood volume)

5. URINARY SYSTEM  KIDNEY (ORGANIZATION) GROSS STRUCTURE:
- RENAL HILUM, PELVIS, AND SINUS C
- RENAL CAPSULE M
- RENAL CORTEX
- RENAL MEDULLA

6. URINARY SYSTEM  KIDNEY (ORGANIZATION) P CORTEX RC MEDULLA
- region immediately beneath renal capsule
- composed of two distinct regions:
(1) CORTICAL LABYRINTH
(2) MEDULLARY RAY
MEDULLA
- located immediately beneath renal cortex
- consists of triangular blocks of tissue called the PYRAMIDS
- RENAL COLUMNS are strands of cortical tissue that extend down between adjacent pyramids

7. URINARY SYSTEM  KIDNEY (ORGANIZATION) P P RENAL LOBE P P P
RENAL LOBULE
- defined within cortex and involves a single medullary ray (central axis of lobule) with adjacent adjacent cortical labyrinth
- defined as a functional unit that consists of a collecting duct and all the nephrons that it drains
Cortical Labyrinth with interdigitating Medullary Rays
 KIDNEY (ORGANIZATION) P P
RENAL LOBE
- a single pyramid with its associated overlying cortex P P P P P

8. URINARY SYSTEM  THE NEPHRON & COLLECTING DUCTS
papilla: collecting ducts empty into minor calyx (beginning of urinary tract)
 THE NEPHRON & COLLECTING DUCTS

9. URINARY SYSTEM  THE NEPHRON & COLLECTING DUCTS 1) THE NEPHRON
- distributed throughout cortex and various zones of medulla
a) RENAL CORPUSCLE
BOWMAN’S CAPSULE + GLOMERULUS
b) PROXIMAL TUBULE
CONVOLUTED AND STRAIGHT PORTIONS
nephron: uriniferous tubules distributed throughout renal cortex anD medulla important for water/electrolyte balance, acid/base balance, and regulation of blood pressure & volume (renin). 2 MILLION PER KIDNEY
c) HENLE’S LOOP
THICK AND THIN PORTIONS
d) DISTAL TUBULE
STRAIGHT AND CONVOLUTED PORTIONS
2) COLLECTING DUCTS

10. URINARY SYSTEM  THE NEPHRON & COLLECTING DUCTS CORTEX:
CORTICAL LABYRINTH
1- RENAL CORPUSCLES
2- PROXIMAL CONVOLUTED TUBULES
3- DISTAL CONVOLUTED TUBULES
DISTRIBUTION OF TUBULES
MEDULLARY RAY
1- STRAIGHT PORTIONS OF PROXIMAL TUBULE (THICK DESCENDING)
2- STRAIGHT PORTIONS OF DISTAL TUBULE (THICK ASCENDING)
3- COLLECTING DUCTS

11. URINARY SYSTEM  THE NEPHRON & COLLECTING DUCTS MEDULLA: OUTER ZONE
1- STRAIGHT PORTIONS OF PROXIMAL TUBULE (THICK DESCENDING)
2- STRAIGHT PORTIONS OF DISTAL TUBULE (THICK ASCENDING)
3- THIN SEGMENTS OF LOOP OF HENLE (DESCENDING & ASCENDING)
4- COLLECTING DUCTS
INNER ZONE
1- THIN SEGMENTS OF LOOP OF HENLE (DESCENDING & ASCENDING)
2- COLLECTING DUCTS

12. URINARY SYSTEM  BLOOD FLOW (KIDNEY) RENAL LOBULE AORTA RENAL ARTERY
INTERLOBAR ARTERIES
- run between lobes in medulla
ARCUATE ARTERIES
- run parallel to bases of pyramids at the corticomedullary junction
INTERLOBULAR ARTERIES
- delineate lateral limits of renal lobules
AFFERENT ARTERIOLES
- supply blood to glomerulus
GLOMERULAR CAPILLARY BED
EFFERENT ARTERIOLES
- drain blood from glomerulus and form either peritubular capillary plexus (cortex) or vasa recta system (medulla)

13. PERITUBULAR CAPILLARY PLEXUS
RENAL LOBULE
URINARY SYSTEM
 BLOOD FLOW (KIDNEY)
VENA CAVA
RENAL VEIN
INTERLOBAR VEINS
- run between lobes in medulla
ARCUATE VEINS
- run parallel to bases of pyramids at the corticomedullary junction
INTERLOBULAR VEINS
- delineate lateral limits of renal lobules
PERITUBULAR CAPILLARY PLEXUS
VASA RECTA SYSTEM

14. URINARY SYSTEM ea G G  BLOOD FLOW (KIDNEY) aa G IA CA1
injection of colored colloidin in renal artery
IA = interlobular artery

15. URINARY SYSTEM  THE NEPHRON & COLLECTING DUCTS
HISTOLOGICAL STRUCTURE AND FUNCTION
1) THE NEPHRON
- distributed throughout cortex and various zones of medulla
a) RENAL CORPUSCLE
BOWMAN’S CAPSULE + GLOMERULUS
b) PROXIMAL TUBULE
KNOW DISTRIBUTION; BEGIN LOOKING AT DETAILED STRUCTURE AND FUNCTION
CONVOLUTED AND STRAIGHT PORTIONS
c) HENLE’S LOOP
THICK AND THIN PORTIONS
d) DISTAL TUBULE
STRAIGHT AND CONVOLUTED PORTIONS
2) COLLECTING DUCTS

16. URINARY SYSTEM  THE NEPHRON & COLLECTING DUCTS
HISTOLOGICAL STRUCTURE AND FUNCTION
1) THE NEPHRON
- distributed throughout cortex and various zones of medulla
a) RENAL CORPUSCLE
BOWMAN’S CAPSULE + GLOMERULUS
b) PROXIMAL TUBULE
note the epithelial changes that occur along the uriniferous tubules (reflects function)
CONVOLUTED AND STRAIGHT PORTIONS
c) HENLE’S LOOP
THICK AND THIN PORTIONS
d) DISTAL TUBULE
STRAIGHT AND CONVOLUTED PORTIONS
2) COLLECTING DUCTS

17. URINARY SYSTEM  RENAL CORPUSCLE BOWMAN’S CAPSULE + GLOMERULUS
FILTRATION APPARATUS OF KIDNEY
1. BOWMAN’S CAPSULE:
- the beginning of the nephron that consists of a blind sac lined with simple squamous epithelium that is continuous with the PCT
- parietal layer & visceral layer (specialized)
2. GLOMERULUS:
- specialized tuft of capillaries which housed in the capsular space (10-20 capillary loops)
- blood flowing through glomerulus capillaries undergoes a filtration process to produce the initial urine filtrate

18. URINARY SYSTEM  RENAL CORPUSCLE VASCULAR POLE URINARY POLE
BOWMAN’S CAPSULE + GLOMERULUS
FILTRATION APPARATUS OF KIDNEY
VASCULAR POLE
URINARY POLE
GLOMERULUS (FILTRATION MEMBRANE):
1- fenestrated capillaries; discontinuous endothelium; fenestrae have a diameter of Å and lack a diaphragm
2- continuous basal lamina
3- podocytes of visceral layer; processes contact basal lamina and are separated by slits measuring approximately 250Å

19. URINARY SYSTEM  RENAL CORPUSCLE BOWMAN’S CAPSULE + GLOMERULUS
FILTRATION APPARATUS OF KIDNEY
GLOMERULUS (FILTRATION MEMBRANE):
prevents RBC’s and large MW proteins from leaving circulation, while most other blood constituents pass easily into the capsular space
MESANGIAL CELLS
- phagocytic cells with a surrounding matrix that lend structural support to the glomerulus

20. URINARY SYSTEM  RENAL CORPUSCLE BOWMAN’S CAPSULE + GLOMERULUS
FILTRATION APPARATUS OF KIDNEY
GLOMERULUS (FILTRATION MEMBRANE):
1- fenestrated capillaries
2- continuous basal lamina
3- podocytes

21. PODOCYTE
1° process
pedicels 2°

23. kidney-02