Swinburne University BIO10004 Anatomy & Physiology PDF

BIO10004 – Anatomy and Physiology The Urinary System Dr Greg Davis  WARNING This material has been reproduced and communicated to you by or on behalf of Swinburne University of Technology in accordance with Section 113P of the Copyright Act 1968 (the Act). The mater...

BIO10004 – Anatomy and Physiology The Urinary System Dr Greg Davis  WARNING This material has been reproduced and communicated to you by or on behalf of Swinburne University of Technology in accordance with Section 113P of the Copyright Act 1968 (the Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. Learning objectives and reading At the end of this lecture, you should be able to: 1. Identify the organs of the urinary system and describe the functions of the system 2. Describe the location and structures of the kidneys 3. Describe the urine collecting system 4. Describe the structure of a nephron and the basic processes of urine formation 5. Describe the structures of ureters, urinary bladder and urethra Reading guide (textbook): Fundamentals of Anatomy & Physiology, Martini et al., Eleventh Edition, Chapters 26  Overview Kidney Overall functions: produce and eliminate urine Ureter Excretion Removal of metabolic wastes from body fluids Elimination Discharge of wastes from body Bladder Homeostatic Urethra regulation of volume and solute concentration of blood Wolters Kluwer, Lippincott Williams & Wilkins, Atlas of Anatomy, 2009, ISBN 9780781785051, Chapter 5, plate 5-30  Kidneys (in situ, anterior view) Diaphragm Shape and Position Kidney Function: Produce urine and regulation of homeostasis Wolters Kluwer, Lippincott Williams & Wilkins, Atlas of Anatomy, 2009, ISBN 9780781785051, Chapter 5, plate 5-30  Location of Kidneys Netter, F.H. Interactive Atlas of Human Anatomy. 3rd ed. New Jersey, Icon Learning Systems, 2003, ISBN: 1-929007-15-9, Plate #309  Kidney Structure Renal Cortex capsule Medulla (renal pyramid) Renal sinuses Fat in the renal sinuses Moore K L. Clinically Oriented Anatomy, 7th ed. Williams and Wilkins; 2013. ISBN 9781451119459. Chapter 2, Figure 2.80  Renal Collecting System Medulla (renal pyramid) Renal papilla (tip of renal pyramid) Minor calyx Calices Major calyx Renal pelvis (pass through renal hilum) Ureter Moore K L. Clinically Oriented Anatomy, 7th ed. Williams and Wilkins; 2013. ISBN 9781451119459. Chapter 2, Figure 2.80 Arterial Supply to the Kideys Renal artery Kidneys receive 20–25% of total cardiac output About 1.2 L of blood flow through kidneys each minute Renal arterial supply Moore K L. Clinically Oriented Anatomy, 7th ed. Williams and Wilkins; 2013. ISBN 9781451119459. Chapter 2, Figure 2.84 Nephron Cortical nephron (the operating unit) Juxtamedullary Cortex nephron Microscopic functional units of kidneys Two types of nephrons Cortical Nephron Juxtamedullary nephron Medulla Collecting duct Papillary duct Renal papilla Minor calyx Fundamentals of Anatomy and Physiology 2020; 11th Edition  NEPHRON Anatomy of a Nephron a Proximal Convoluted Tubule Distal Convoluted Tubule Cuboidal cells with abundant microvilli Cuboidal cells with few microvilli Mitochondria Each consists of renal corpuscle and renal tubule Renal corpuscle (Spherical structure) Renal Corpuscle Renal tubule Glomerular (Bowman’s) capsule Glomerulus (capillary network) Squamous cells Renal tubule (Convoluted segments) Glomerulus Proximal convoluted tubule (PCT) Glomerulus Nephron loop (loop of Henle, U-shaped tube) Glomerular capsule Ascending Descending Distal convoluted tubule (DCT) Capsular space limb of limb of loop ends loop begins Nephron Loop Descending thin Squamous cells limb (DTL) Thick ascending Low cuboidal cells limb (TAL) Ascending thin Squamous cells limb (ATL) Fundamentals of Anatomy and Physiology 2020; 11th Edition  Glomerular Filtration Glomerulus Efferent Basement arteriole membrane Capillary lumen Afferent arteriole Filtration Podocyte slit Foot processes of podocytes Filtration occurs exclusively in the renal corpuscle, across Capsular the filtration membrane space Podocytes: Large cells that wrap around glomerular capillaries Filtration membrane Fundamentals of Anatomy and Physiology 2020; 11th Edition Overview of Urine Proximal Convoluted Tubule Distal Convoluted Tubule Formation Reabsorption of water, ions, Secretion of ions, acids, drugs, toxins and all organic nutrients Variable reabsorption of water, sodium ions, and calcium ions (under hormonal control) Filtration Renal Corpuscle Blood pressure forces water and Production of filtrate solutes across walls of Glomerulus glomerular capillaries Glomerular capsule Collecting Duct Reabsorption Collecting duct Variable reabsorption of water and reabsorption Movement of water and solutes Nephron Loop or secretion of sodium, potassium, hydrogen, Descending thin limb (e.g ions and organic nutrients) Further reabsorption and bicarbonate ions of water Thick ascending limb Secretion Reabsorption of sodium and chloride ions Transport of solutes KEY Papillary Duct Filtration occurs exclusively in the renal corpuscle, across the filtration membrane. Delivery of urine to minor calyx Water reabsorption occurs primarily along the PCT and the descending thin limb of the nephron loop, but also to a variable degree in the DCT and collecting system. Urine storage and elimination Variable water reabsorption occurs in the DCT and collecting system. Solute reabsorption occurs along the PCT, the thick ascending limb of the nephron loop, the DCT, and the collecting system. Variable solute reabsorption or secretion occurs at the PCT, the DCT, and the collecting system.  Function of the Nephron Corpuscle Proximal Loop Distal Removes plasma 60-70% water Na+ and Cl- ions Na+ and Cl- ions proteins reabsorbed reabsorbed reabsorbed Glucose Ca2+ reabsorbed Sugars, ions H+ ions, reabsorbed creatinine, drugs, toxins secreted H+ ions secreted  Ureters Ureter Wolters Kluwer, Lippincott Williams & Wilkins, Atlas of Anatomy, 2009, ISBN 9780781785051, Chapter 5, plate 5-30  Urinary Bladder Female Male Rectum Rectum Uterus A hollow viscus with strong muscular walls Position: most anterior of pelvic viscera Pyramidal-shaped: Apex anterior and Base posterior Wolters Kluwer, Lippincott Williams & Wilkins, Atlas of Anatomy, 2009, ISBN 9780781785051, Chapter 6, Plate 6-09  Urinary Bladder (internal view, coronal section) Ureteric orifices Urethral orifice (internal) Urethra Wolters Kluwer, Lippincott Williams & Wilkins, Atlas of Anatomy, 2009, ISBN 9780781785051, Chapter 6, Plate 6-10 Female Urethra Short (~4cm long) Orifices and normal narrowing sites Pass through the pelvic floor and perineal membrane Distensible (contain more elastic tissues/smooth muscles than male urethra) Drake R L, Vogl W, Mitchell A W M. Gray’s Anatomy For Students. Churchill Livingstone; 2005. ISBN 0808923064. Fig. 5.44 Male Urethra Long (~20cm long) Divided into 4 parts Bends twice along its course Orifices and normal narrowing sites Drake R L, Vogl W, Mitchell A W M. Gray’s Anatomy For Students. Churchill Livingstone; 2005. ISBN 0808923064. Fig. 5.44 Thank you!