chapter 20: urinary system
Upcoming SlideShare
Loading in...5
×
 

chapter 20: urinary system

on

  • 854 views

urinary system

urinary system

Statistics

Views

Total Views
854
Views on SlideShare
455
Embed Views
399

Actions

Likes
1
Downloads
26
Comments
0

3 Embeds 399

http://ivyanatomy.com 362
http://www.ivyanatomy.com 35
http://www.slideee.com 2

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

chapter 20: urinary system chapter 20: urinary system Presentation Transcript

  • Hole’s Human Anatomy and Physiology Twelfth Edition Shier  Butler  Lewis Chapter 20 Urinary System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1
  • 20.1: Introduction • A major part of homeostasis is maintaining the composition, pH, and volume of body fluids within normal limits • The urinary system removes metabolic wastes and substances in excess, including foreign substances like drugs and their metabolites that may be toxic • It consists of a pair of kidneys, a pair of ureters, a urinary bladder and a urethra 2
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Renal vein Hilum Renal artery Inferior vena cava Abdominal aorta Ureters Urinary bladder Urethra © CNRI/SPL/Photo Researchers, Inc. 3
  • 20.2: Kidneys • A kidney is a reddish brown, bean-shaped organ with a smooth surface • In the adult it is about 12 centimeters long, 6 centimeters wide, and 3 centimeters thick • It is enclosed in a tough, fibrous capsule 4
  • Location of the Kidneys Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Kidney Adipose tissue Parietal peritoneum Spleen Inferior vena cava Aorta Small intestine Large intestine Pancreas Stomach (a) Adrenal gland Twelfth rib Liver Kidney Parietal peritoneum Renal fascia Renal fascia Hip bone (cut) Large intestine (b) 5
  • Kidney Structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Renal cortex Renal medulla Renal capsule Renal corpuscle Nephrons Renal cortex Minor calyx Major calyx Renal medulla Renal sinus Renal column Fat in renal sinus Collecting duct Papilla Renal pelvis Renal tubule Minor calyx Renal papilla (b) (c) Renal pyramid Ureter (a) 6
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Inferior vena cava Abdominal aorta Suprarenal artery Suprarenal vein Adrenal gland Renal artery Renal column Renal capsule Renal pelvis Renal papilla Renal vein Renal medulla Hilum Renal pyramid Renal cortex Ureter Minor calyx 7
  • Function of the Kidneys • The main function of the kidneys is to regulate the volume, composition, and pH of body fluids • The kidneys remove metabolic wastes from the blood and excrete them to the outside of the body, including nitrogenous and sulfur-containing products of protein metabolism • The kidneys also help control the rate of red blood cell production, regulate blood pressure, and regulate calcium ion absorption 8
  • Renal Blood Vessels Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cortical radiate artery and vein Proximal Cortex convoluted tubule Arcuate vein and artery Medulla Efferent arteriole Interlobar vein and artery Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cortical radiate artery and vein Afferent arteriole Distal convoluted tubule Peritubular capillary Renal artery Renal vein Renal pelvis Efferent Afferent arteriole arteriole Glomerulus (a) Ureter Peritubular capillary (a) Renal tubules (b) Glomerulus Glomerular capsule (a) : Tissues and Organs: A Text-Atlas of Scanning Electron Microscopy, by R.G. Kessel and R.H. Kardon. © 1979 W.H. Freeman and Company (b) : Courtesy of R.B. Wilson MD, Eppeley Institute for Research in Cancer, University of Nebraska Medical Center 9 (b) b: © L.V. Bergman/The Bergman Collection
  • Nephrons Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Afferent arteriole Blood flow Efferent arteriole Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slit pore Pedicel Primary process of podocyte Blood flow Glomerular capsule Parietal layer of glomerular capsule Slit pore Glomerulus Proximal convoluted tubule Visceral layer of glomerular capsule Pedicel Primary process of podocyte © David M. Phillips/Visuals Unlimited 10
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerular capsule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cortical radiate artery Cortical radiate vein Proximal convoluted tubule Collecting ducts Glomerulus Afferent arteriole Efferent arteriole Distal convoluted tubule Renal cortex From renal artery Peritubular capillary Nephron loop Epithelial cell Renal tubules Glomerular Glomerulus capsule Renal corpuscle To renal vein Descending limb Ascending limb Blood vessel (a) (b) a: © Biophoto Associates/Photo Researchers, Inc., b: © Manfred Kage/Peter Arnold Renal medulla Collecting duct 11
  • Juxtaglomerular Apparatus Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Afferent Glomerular arteriole capsule Glomerulus Juxtaglomerular apparatus Distal convoluted tubule Efferent arteriole Proximal convoluted tubule Glomerulus Podocyte Afferent arteriole Nephron loop (a) Juxtaglomerular cells Macula densa Glomerular capsule Efferent arteriole (b) Juxtaglomerular apparatus Ascending limb of nephron loop 12
  • Cortical and Juxtamedullary Nephrons Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cortical nephron Renal cortex Juxtamedullary nephron Renal medulla Collecting duct 13
  • Blood Supply of a Nephron Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerular capsule Renal artery Cortical radiate artery and vein Interlobar artery Proximal convoluted tubule Glomerulus Efferent arteriole Arcuate artery Afferent arteriole Distal convoluted tubule Cortical radiate artery Afferent arteriole Peritubular capillaries Glomerular capillaries Efferent arteriole Vasa recta Peritubular capillaries Cortical radiate vein Arcuate vein Collecting duct Interlobar vein Nephron loop Renal vein 14
  • 20.3: Urine Formation • The main function of the nephrons and collecting ducts is to control the composition of body fluids and remove wastes from the blood, the product being urine • Urine contains wastes, excess water, and electrolytes • Urine is the final product of the processes of: • Glomerular filtration • Tubular reabsorption • Tubular secretion 15
  • Urine Formation Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Arteriole Venule Net reabsorption Blood flow Net filtration Interstitial fluid (a) In most systemic capillaries, filtration predominates at the arteriolar end and osmotic reabsorption predominates at the venular end. Afferent arteriole Glomerular capillaries Efferent arteriole Peritubular capillaries Venule Blood flow Glomerular filtration Filtered fluid Tubular reabsorption Tubular secretion Tubular fluid Urine Renal tubule (b) In the kidneys, the glomerular capillaries are specialized for filtration. The renal tubule is specialized to control movements of substances back into the blood of the peritubular capillaries (tubular reabsorption) or from the blood into the renal tubule (tubular secretion). 16
  • Glomerular Filtration • Glomerular filtration • Substances move from the blood to the glomerular capsule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Glomerulus Proximal convoluted tubule Afferent arteriole Capillary endothelium Podocyte Glomerular filtrate Glomerular capsule Fenestrae Blood flow Podocyte Efferent arteriole (a) (b) 17
  • Plasma, Glomerular Filtrate, and Urine Components 18
  • Filtrate Pressure • The main force that moves substances by filtration through the glomerular capillary wall is hydrostatic pressure of the blood inside Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hydrostatic pressure of blood Glomerular hydrostatic pressure Capsular hydrostatic pressure Plasma colloid osmotic pressure Net Outward Pressure Outward force, glomerular hydrostatic pressure = Inward force of plasma colloid osmotic pressure = Inward force of capsular hydrostatic pressure = Net filtration pressure = +60 mm –32 mm –18 mm +10 mm 19
  • Filtrate Rate • Glomerular filtration rate (GFR) is directly proportional to the net filtration pressure Net filtration pressure = force favoring filtration (glomerular capillary hydrostatic pressure) – forces opposing filtration (capsular hydrostatic pressure and glomerular capillary osmotic pressure) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 170 160 150 140 130 120 110 Liters • Normally the glomerular net filtration pressure is positive causing filtration • The forces responsible include hydrostatic pressure and osmotic pressure of plasma and the hydrostatic pressure of the fluid in the glomerular capsule 180 Liters 180 100 90 80 70 60 50 40 30 20 10 0.6 – 2.5 Liters 0 Urine Glomerular filtrate (a) (b) 20
  • Control of Filtrate Rate • GFR remains relatively constant through a process called autoregulation • Certain conditions override autoregulation, including when GFR increases • Primarily three mechanisms are responsible for keeping the GFR constant: • Autoregulation • Increased sympathetic impulses that decrease GFR by causing afferent arterioles to constrict • The hormone-like renin-angiotensin system • There also is the hormone atrial natriuretic peptide (ANP) affects sodium causing an increase in GFR 21
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lung capillaries Liver Kidney Renin Angiotensinogen Angiotensinconverting enzyme Angiotensin I Angiotensin II Bloodstream Release into bloodstream Stimulation • Vasoconstriction • Increased aldosterone secretion • Increased ADH secretion • Increased thirst 22
  • Tubular Reabsorption • Tubular reabsorption • Substances move from the renal tubules into the interstitial fluid where they then diffuse into the peritubular capillaries • The proximal convoluted tubule reabsorbs (70%): • Glucose, water, urea, proteins, and creatine • Amino, lactic, citric, and uric acids • Phosphate, sulfate, calcium, potassium, and sodium ions 23
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood flow Blood flow Afferent arteriole Glomerular capsule Efferent arteriole Glomerulus Glomerular filtrate Afferent arteriole Glomerular capsule Efferent arteriole Glomerulus Glomerular filtrate Peritubular capillary Tubular reabsorption Peritubular capillary Renal tubule Renal tubule (a) Tubular secretion Blood flow (b) Blood flow 24
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood flow Glomerulus Glomerular capsule Blood flow Glomerular filtrate Proximal convoluted tubule Na+ Na+ + + Cl– – – – – PO4–3 HCO3– N+ Cl– Na+ H2O H2O Isotonic tubular fluid + – + – + +– – + – + – + ++ – + +– – – ++ – – 1 Sodium ions are reabsorbed by active transport 2 Negatively charged ions are attracted to positively charged ions 3 As concentration of ions (solute) increases in plasma, osmotic pressure increases 4 Water moves from proximal tubule to capillary by osmosis Peritubular capillary Blood flow 25
  • 26
  • Tubular Secretion • Tubular secretion • Substances move from the plasma of the peritubular capillaries into the fluid of the renal tubules • Active transport mechanisms function here • Secretion of substances such as drugs and ions 27
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Peritubular capillary Blood flow K+ or H+ Tubular reabsorption Na+ Na+ Na+ Na+ Na+ Na Tubular secretion Na+ + Tubular fluid Na+ H+ K+ K+ K+ Na+ Na+ H+ Distal convoluted tubule Na+ K+ Na+ Na+ Ascending limb of nephron loop Collecting duct 28
  • Regulation of Urine Concentration and Volume • Hormones such as aldosterone and ANP affect the solute concentration of urine, particularly sodium • The ability of the kidneys to maintain the internal environment rests in a large part on their ability to concentrate urine by reabsorbing large volumes of water • The distal convoluted tubule and the collecting duct are impermeable to water, so water may be excreted as dilute urine • If ADH is present, these segments become permeable, and water is reabsorbed by osmosis into the extremely hypertonic medullary interstitial fluid • A countercurrent mechanism in the nephron loops (the descending and the ascending limbs) ensures that the medullary interstitial fluid becomes hypertonic • This mechanism is known as the countercurrent multiplier • The vasa recta also contributes as a countercurrent mechanism 29
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Distal convoluted tubule Medullary interstitial fluid H2O H2O H2O H2O H2O Hypertonic interstitial fluid Collecting duct Hypertonic interstitial fluid H2O Dilute urine (a) low ADH levels Medullary interstitial fluid H2O H2O Collecting duct Concentrated urine (b) high ADH levels 30
  • 31
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 H2 O Na+ Cl– Salty Increasing NaCl concentration Cl– Na+ Isotonic fluid Cl Na+ – H2 O H2 O Descending limb (permeable to water) (a) H2 O Cl– Na+ 2 H2 O Hypotonic fluid More salty Thick ascending limb (impermeable to water) 3 Medullary interstitial fluid Hypertonic fluid Na+ Cl– H2 O Na+ Cl– Even more salty (b) 32
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood flow Blood flow Increasing NaCl concentration NaCl NaCl Medullary interstitial fluid NaCl NaCl NaCl NaCl NaCl NaCl Vasa recta 33
  • 34
  • Urea and Uric Acid Excretion • Urea: • A by-product of amino acid catabolism • The plasma concentration reflects the amount or protein in diet • It enters the renal tubules through glomerular filtration • It contributes to the reabsorption of water from the collecting duct • About 80% is recycled • Uric acid: • Is a product of nucleic acid metabolism • It enters the renal tubules through glomerular filtration • Most reabsorption occurs by active transport • About 10% is secreted and excreted 35
  • Urine Composition • Urine composition reflects the volumes of water and solutes that the kidneys must eliminate from the body or retain in the internal environment to maintain homeostasis • It varies from time to time due to dietary intake and physical activity, but is: • About 95% water • Usually contains urea, uric acid, and creatinine • May contain trace amounts of amino acids and varying amounts of electrolytes • Volume varies with fluid intake and environmental factors 36
  • Renal Clearance • This is the rate at which a chemical is removed from the plasma • It indicates kidney efficiency • Tests of renal clearance: • Inulin clearance test • Creatinine clearance test • Para-aminohippuric acid (PAH) test • These tests of renal clearance are used to calculate the GFR (glomerular filtration rate) 37
  • 20.4: Elimination of Urine • After forming along the nephrons, urine: • Passes the collecting ducts to: • Openings of the renal papillae: • Enters the minor and major calyces: • Passes through the renal pelvis: • Enters into the ureters: • Enters into the urinary bladder: •The urethra carries the urine out of the body 38
  • Ureters • The ureters: • Each is about 25 centimeters long • Extends downward posterior to the parietal peritoneum • Runs parallel to vertebral column • Join the urinary bladder in the pelvic cavity • The wall of ureter has three layers: • The inner mucous coat • The middle muscular coat • The outer fibrous coat 39
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Mucous coat Lumen Muscular coat Fibrous coat Adipose tissue © Per H. Kjeldsen 40
  • Urinary Bladder • The urinary bladder is a hollow, distensible, muscular organ located within the pelvic cavity, posterior to the symphysis pubis and inferior to the parietal peritoneum • It contacts the anterior walls of the uterus and vagina in the female, and lies posteriorly against the rectum in the male • The openings for the ureters is the area of trigone • It has four layers: inner mucous coat, a submucous coat, a muscular coat, and an outer serous coat • Smooth muscle fibers comprise the detrusor muscle which is the muscle of the bladder wall 41
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Ureter Abdominal wall Parietal peritoneum Urinary bladder Symphysis pubis Prostate gland Urethra Rectum Rectum (a) (b) 42
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Serous coat Ureter Urinary bladder Ureter Detrusor muscle Submucous coat Ductus (vas) deferens Mucous coat Openings of the ureters Seminal vesicle Trigone Neck Prostate gland Internal urethral sphincter Prostate gland Urethra Region of external urethral sphincter (a) Urethra (b)
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Muscular coat Mucous coat Submucous coat Lumen © John D. Cunningham/Visuals Unlimited 44
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Ureter Urinary bladder Trigone Urethra External urethral orifice (a) Ureter Urinary bladder Trigone Prostatic urethra Membranous urethra Penile urethra External urethral orifice (b) Prostate gland Bulbourethral gland Penis 45
  • Urethra • The urethra is a tube that conveys urine from the urinary bladder to the outside of the body • Its wall is lined with a mucous membrane and it has a thick layer of longitudinal smooth muscle fibers • In a female: • It is about 4 centimeters long • It runs obliquely • In a male: • It is about 17.5 centimeters long • It has a dual function for both urination and reproduction • It has three sections: • Prostatic urethra • Membranous urethra 46 • Penile urethra
  • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Urethral glands Muscle layer Lumen of urethra Mucous membrane © Ed Reschke 47
  • Micturition • Urine leaves the urinary bladder by micturition or urination reflex 48
  • Micturition 49
  • 20.5: Lifespan Changes • The urinary system is sufficiently redundant, in both structure and function, to mask age-related changes • The kidneys become slower to remove nitrogenous wastes and toxins and to compensate for changes that maintain homeostasis • Changes include: • The kidneys appear scarred and grainy • Kidney cells die • By age 80 the kidneys have lost a third of their mass • Kidney shrinkage is due to loss of glomeruli • Proteinuria may develop • The renal tubules thicken • It is harder for the kidneys to clear certain substances • The bladder, ureters, and urethra lose elasticity • The bladder holds less urine 50