Histology of Urinary System PDF

Abdeslem El Idrissi, PhD Center for Developmental Neuroscience City University of New York College of Staten Island [email protected]  THE URINARY SYSTEM REPRODUCTIVE SYSTEM DIGESTIVE SYSTEM...

Abdeslem El Idrissi, PhD Center for Developmental Neuroscience City University of New York College of Staten Island [email protected]  THE URINARY SYSTEM REPRODUCTIVE SYSTEM DIGESTIVE SYSTEM LYMPATIC SYSTEM SENSORY ORGANS ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education. Histology of the Urinary System  Introduction Urinary system rids the body of waste products Kidneys also play important roles in blood volume, pressure, and composition The urinary system is closely associated with the reproductive system – Shared embryonic development and adult anatomical relationship – Collectively called the urogenital (UG) system ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Functions of the Urinary System Copyright © McGraw-Hill Education. Permission required for reproduction or display. Figure 23.1 ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Functions of the Kidneys Filter blood and excrete toxic metabolic wastes Regulate blood volume, pressure, and osmolarity Regulate electrolytes and acid-base balance Secrete erythropoietin, which stimulates the production of red blood cells Help regulate calcium levels by participating in calcitriol synthesis Clear hormones from blood Detoxify free radicals ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Nitrogenous Wastes Waste—any substance that is useless to the body or present in excess of the body’s needs Metabolic waste—waste substance produced by the body Urea formation – Proteins amino acids removed forms ammonia, – Liver converts ammonia to urea Uric acid – Product of nucleic acid catabolism Creatinine – Product of creatine phosphate catabolism Blood urea nitrogen (BUN)—level of nitrogenous waste in blood – Normal concentration of blood urea is 10 to 20 mg/dL – Azotemia: elevated BUN May indicate renal insufficiency – Uremia: syndrome of diarrhea, vomiting, dyspnea, and cardiac arrhythmia stemming from the toxicity of nitrogenous waste Treatment—hemodialysis or organ transplant ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Major Nitrogenous Wastes ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Excretion Excretion—separating wastes from body fluids and eliminating them Four body systems carry out excretion – Respiratory system , small amounts of other gases, and water – Integumentary system Water, inorganic salts, lactic acid, urea in sweat – Digestive system Water, salts, , lipids, bile pigments, cholesterol, and other metabolic waste – Urinary system Many metabolic wastes, toxins, drugs, hormones, salts, , and water ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior Retroperitoneal Position of the Kidney ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Gross Anatomy of the Kidney Shape and size – About the size of a bar of bath soap – Lateral surface is convex, and medial is concave with a slit, called the hilum Receives renal nerves, blood vessels, lymphatics, and ureter Three protective connective tissue coverings – Renal fascia immediately deep to parietal peritoneum Binds it to abdominal wall – Perirenal fat capsule: cushions kidney and holds it into place – Fibrous capsule encloses kidney protecting it from trauma and infection Collagen fibers extend from fibrous capsule to renal fascia Still drop about 3 cm when going from lying down to standing up ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Gross Anatomy of the Kidney Two zones of renal parenchyma – Outer renal cortex – Inner renal medulla Renal columns—extensions of the cortex that project inward toward sinus Renal pyramids—6 to 10 with broad base facing cortex and renal papilla facing sinus – Lobe of kidney: one pyramid and its overlying cortex – Minor calyx: cup that nestles the papilla of each pyramid; collects its urine – Major calyces: formed by convergence of 2 or 3 minor calyces – Renal pelvis: formed by convergence of 2 or 3 major calyces – Ureter: a tubular continuation of the pelvis that drains urine down to the urinary bladder ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Rt. kidney Lt. kidney Kidney CT: Axial 1 Renal cortex Renal arteries Renal pyramids Renal veins ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Kidney Anatomy Cortex Medulla Pyramids Papilla Minor calyxes Major calyxes Pelvis Ureters Photos © McGraw-Hill Education ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Gross Anatomy of the Kidney 5 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Figure 23.4b ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Kidney Anatomy Cortex Medulla Pyramids Columns ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Papilla Sinuses Minor Major calyces calyces Ureter Renal pelvis Kidney Anatomy ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Renal Circulation ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Renal Circulation Segmental veins ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Renal Circulation 3 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Figure 23.5 ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Microcirculation of the Kidney ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Renal Corpuscle 1 ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Renal Corpuscle 2 Vascular pole—the side of the corpuscle where the afferent arterial enters the corpuscle and the efferent arteriole leaves Urinary pole—the opposite side of the corpuscle where the renal tubule begins ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior Microscopic Anatomy of the Nephron ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Renal Cortex LM: Medium Magnification Glomerulus Proximal convoluted tubule Distal convoluted tubule Photos © McGraw-Hill ©McGraw-Hill Education Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Renal Corpuscle LM: High Magnification Distal convoluted Renal corpuscle tubule Glomerular capsule (parietal Macula densa layer) Photos © McGraw-Hill Education Proximal Vascular pole of Capsular space convoluted tubule renal corpuscle ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Renal Medulla LM: Medium Magnification Collecting duct Vasa recta Thick segment of ascending limb of nephron loop Thin segment of the nephron loop Thick segment of descending limb of nephron loop Photos © McGraw-Hill Education ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Renal Medulla (Longitudinal Section) LM: Medium Magnification Collecting duct Vasa recta Thick segment of Thin segment of nephron loop nephron loop ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Structure of the Glomerulus ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior The Glomerular Filtration Membrane 1 Turned back: Blood cells Plasma proteins Large anions Protein- minerals bound and hormones Most > 8 nm molecules indiamet Passed through er filter: Water Electrolytes Glucose Amino acids Fatty acids Vitamins Urea Uric acid Creatinine ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior The Glomerular Filtration Membrane 2 Glomerular filtration—a special case of capillary fluid exchange in which water and some solutes in the blood plasma pass from the capillaries of the glomerulus into the capsular space of the nephron ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior The Glomerular Filtration Membrane 3 Filtration membrane—three barriers through which fluid passes – Fenestrated endothelium of glomerular capillaries 70 to 90 nm filtration pores – small enough to exclude blood cells Highly permeable – Basement membrane Proteoglycan gel, negative charge, excludes molecules greater than 8 nm Albumin repelled by negative charge Blood plasma is 7% protein, the filtrate is only 0.03% protein – Filtration slits Podocyte cell extensions (pedicels) wrap around the capillaries to form a barrier layer with 30 nm filtration slits Negatively charged which is an additional obstacle for large anions ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Podocytes SEM: High Magnification Podocyte cell body Filtration slits Podocyte primary Podocyte secondary processes processes ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Podocytes Capillary Podocyte cell body TEM: High Magnification Basement membrane Secondary processes of podocytes (pedicels) Capillary Erythrocyte Filtration pores Filtration slits endothelium ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Basic Stages of Urine Formation 1)Glomerular filtration Creates a plasmalike filtrate of the blood 2)Tubular reabsorption Removes useful solutes from the filtrate, returns them to the blood 3)Tubular secretion Removes additional wastes from the blood, adds them to the filtrate 4)Water conservation Removes water from the urine and returns it to blood; concentrates wastes ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Proximal Convoluted Tubule PCT reabsorbs about 65% of glomerular filtrate, removes some substances from blood, and secretes them into tubular fluid for disposal in urine – Prominent microvilli and great length – Abundant mitochondria provide ATP for active transport – PCTs alone account for about 6% of one’s resting ATP and calorie consumption Tubular reabsorption—process of reclaiming water and solutes from tubular fluid and returning them to blood ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Proximal Convoluted Tubule TEM: Low Magnification Proximal convoluted Basolateral tubule interdigitations Brush border of PCT Epithelium of PCT Nuclei of epithelium of PCT ©McGraw-Hill Education. All rights reserved. Authorized only for instructor(Microvilli) use in the classroom. No reproduction or further distribution permitted without the prior The Distal Convoluted Tubule and Collecting Duct 1 Fluid arriving in the DCT still contains about 20% of the water and 7% of the salts from glomerular filtrate – If this were all passed as urine, it would amount to 36 L/day DCT and collecting duct reabsorb variable amounts of water and salt and are regulated by several hormones – Aldosterone, atrial natriuretic peptide, ADH, and parathyroid hormone ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Distal Convoluted Tubule TEM: Low Magnification Distal convoluted tubule Epithelium of DCT Nuclei of epithelium of DCT ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Urine Storage and Elimination Urine is produced continually Does not drain continually from the body Urination is episodic—occurring when we allow it Made possible by storage apparatus and neural controls for timely release ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Ureters 1 Ureters—retroperitoneal, muscular tubes that extend from each kidney to the urinary bladder – About 25 cm long – Pass posterior to bladder and enter it from below – Flap of mucosa at entrance of each ureter acts as a valve into bladder Keeps urine from backing up into ureter when bladder contracts ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Ureters 2 Ureters (Continued) – Three layers of ureter Adventitia—connective tissue layer that connects ureter to surrounding structures Muscularis—two layers of smooth muscle with third layer in lower ureter – Urine enters, it stretches and contracts in peristaltic wave Mucosa—transitional epithelium – Begins at minor calyces and extends through the bladder – Lumen very narrow, easily obstructed by kidney stones ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Ureter LM: Low Magnification Transitional Adventitia of ureter epithelium Mucosa of ureter Muscularis of ureter ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Ureter LM: High Magnification Mucosa of ureter Transitional epithelium of ureter ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Urinary Bladder 1 Urinary bladder—muscular sac located on floor of the pelvic cavity – Inferior to peritoneum and posterior to pubic symphysis Three layers – Covered by parietal peritoneum, superiorly, and by fibrous adventitia elsewhere – Muscularis: detrusor: three layers of smooth muscle – Mucosa: transitional epithelium Umbrella cells on surface of epithelium protect it from the hypertonic, acidic urine ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Urinary Bladder 2 Trigone—smooth-surfaced triangular area on bladder floor that is marked with openings of ureters and urethra Capacity—moderate fullness is 500 mL, maximum fullness is 700 to 800 mL – Highly distensible – As it fills, it expands superiorly – Rugae flatten – Epithelium thins from five or six layers to two or three ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Urinary Bladder 3 (a) Female ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Urinary Bladder Female bladder Detrusor Muscle Male Trigone bladder Rugae Internal Urethral Orifice ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Urinary Bladder Histology Bladder Transitional Lamina wall epithelium propria Detrusor Submucosa muscle Photos © McGraw-Hill Education ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Urinary Bladder LM: Low Magnification Transitional epithelium of bladder Detrusor muscle Lamina propria of Submucosa of bladder bladder Photos © McGraw-Hill Education ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  Transitional epithelium of Lamina propria urinary bladder of urinary bladder Urinary Bladder LM: High Magnification ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Urethra 1 Urethra is tube that conveys urine out of body Female urethra: – 3 to 4 cm long, bound to anterior wall of vagina – External urethral orifice is between vaginal orifice and clitoris External urethral sphincter – Where urethra passes through the pelvic floor – Skeletal muscle - voluntary control ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Female Urethra Copyright © McGraw-Hill Education. Permission required for reproduction or display. (a) Female Figure 23.23a ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Urethra 2 Male urethra: 18 cm long Three regions – Prostatic urethra (2.5 cm) Passes through prostate – Membranous urethra (0.5 cm) Passes through muscular floor of pelvic cavity – Spongy (penile) urethra (15 cm) Passes through penis in corpus spongiosum Internal urethral sphincter – Detrusor muscle thickening External urethral sphincter – Skeletal muscle of pelvic floor ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior  The Male Urethra Copyright © McGraw-Hill Education. Permission required for reproduction or display. Figure 23.23b (b) Male ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior