URINARY SYSTEM: I

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  TO CORRELATE STRUCTURE OF VARIOUS COMPONENTS WITH FUNCTION

3. URINARY SYSTEM  KIDNEY 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. P P P P P RC P P URINARY SYSTEM  KIDNEY (ORGANIZATION) CORTEX - 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. Cortical Labyrinth with interdigitating Medullary Rays RENAL LOBE - a single pyramid with its associated overlying cortex 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 URINARY SYSTEM  KIDNEY (ORGANIZATION) P P P P P P P

8. URINARY SYSTEM  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 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 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. RENAL LOBULE URINARY SYSTEM  BLOOD FLOW (KIDNEY) 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. 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

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 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 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 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 500-1000Å 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°