Structure and Function of the Renal and Urologic

Structure and Function of the Renal and Urologic Systems Chapter 35 1

Structures of the Kidney o Kidneys n n Retroperitoneal Renal capsule Renal fascia Hilum 2 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney 3 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney o o o o Renal cortex Renal medulla Renal pyramids Renal columns Minor calyx Major calyx Renal pelvis 4 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney 5 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron o o 1. 2 million nephrons per kidney Functional unit of the kidney n n n Superficial cortical nephrons Midcortical nephrons Juxtamedullary nephrons 6 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron o Renal corpuscle n n n o Glomerulus Bowman capsule Mesangial cells Bowman space 7 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron o Glomerular filtration membrane n n n Glomerular endothelium Basement membrane Capillary epithelium o o Also referred to as podocytes or visceral epithelium Filtration slits 8 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron o Juxtaglomerular apparatus n n Juxtaglomerular cells Macula densa 9 Mosby items and derived items © 2006 by Mosby, Inc.

Juxtaglomerular Apparatus 10 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron o Renal tubules n n n Proximal tubule Loop of Henle Distal tubule Collecting duct Principal cells Intercalated cells 11 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney 12 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney 13 Mosby items and derived items © 2006 by Mosby, Inc.

Blood Vessels o o o o Renal arteries Interlobar arteries Arcuate arteries Interlobular arteries Afferent arterioles Glomerular capillaries Efferent arterioles Peritubular capillaries and vasa recta 14 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney 15 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney o Ureters n n n 30 cm long Long, intertwining muscle bundles Pass obliquely though posterior aspect of bladder Peristaltic activity Micturition compresses the lower end of the ureter to avoid urine reflux 16 Mosby items and derived items © 2006 by Mosby, Inc.

Structures of the Kidney o Bladder n n o Detrusor muscle Transitional epithelium Trigone Micturition reflex Urethra n n n Internal and external sphincters 3 to 4 cm in females 18 to 20 cm in males 17 Mosby items and derived items © 2006 by Mosby, Inc.

Bladder and Urethra 18 Mosby items and derived items © 2006 by Mosby, Inc.

Renal Blood Flow o o o Receive 1000 to 1200 m. L of blood per minute Glomerular filtration rate (GFR) Autoregulation n n o o Myogenic mechanism Tubuloglomerular feedback Neural regulation Hormones n n Renin-angiotensin system Natriuretic peptides 19 Mosby items and derived items © 2006 by Mosby, Inc.

Renal Blood Flow 20 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron Function o Glomerular filtration n Net filtration pressure o o o n Glomerular hydrostatic pressure Capsular hydrostatic pressure Blood oncotic pressure Filtration rate 21 Mosby items and derived items © 2006 by Mosby, Inc.

Glomerular Filtration 22 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron Function o o Tubular reabsorption Tubular secretion Excretion Tubular transport n n n Proximal tubule Loop of Henle and distal tubule Glomerulotubular balance 23 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron Function 24 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron Function 25 Mosby items and derived items © 2006 by Mosby, Inc.

Nephron Function 26 Mosby items and derived items © 2006 by Mosby, Inc.

Concentration and Dilution of Urine o Countercurrent exchange system n n Contributes to production of concentrated urine Fluid flows in opposite direction through parallel tubes Fluid moves up and down the parallel limbs of the loop of Henle The longer the loop, the greater the concentration gradient 27 Mosby items and derived items © 2006 by Mosby, Inc.

Countercurrent Exchange System 28 Mosby items and derived items © 2006 by Mosby, Inc.

Concentration and Dilution of Urine o o o Urea Catecholamines Antidiuretic hormone (ADH) Urodilantin Natriuretic peptide Diuretics 29 Mosby items and derived items © 2006 by Mosby, Inc.

Renal Hormones o o Vitamin D Erythropoietin 30 Mosby items and derived items © 2006 by Mosby, Inc.

Tests of Renal Function o Clearance and glomerular filtration rate n n o o Inulin Creatinine Clearance and renal blood flow Blood tests n n n Plasma creatinine concentration Plasma cystatin C concentration Blood urea nitrogen (BUN) 31 Mosby items and derived items © 2006 by Mosby, Inc.

Tests of Renal Function o Urinalysis n n Urine color Urine p. H Specific gravity Urine sediment o o RBCs Casts Crystals WBCs 32 Mosby items and derived items © 2006 by Mosby, Inc.

Tests of Renal Function o Urinalysis n Reagent strips (dipsticks) o o o o Glucose Bilirubin Urobilinogen Leukocyte esterase Nitrates Ketones Proteins RBCs, hemoglobin, and myoglobin 33 Mosby items and derived items © 2006 by Mosby, Inc.

Aging and Renal Function o o o Decrease in kidney size Decrease in renal blood flow and GFR Number of nephrons decrease due to renal vascular and perfusion changes Glomerular capillaries atrophy Tubular transport response decreases Increased bladder symptoms n Urgency, frequency, and nocturia 34 Mosby items and derived items © 2006 by Mosby, Inc.