UST General Santos Anatomy and Physiology with Pathophysiology - Unit 13 PDF

PRAYER BEFORE CLASS Holy Spirit, Divine Creator, true source of light and fountain of wisdom! Pour forth your brilliance upon my dense intellect, dissipate the darkness which covers me, that of sin and of ignorance. Grant me a penetrating mind to understand, a retentive memory, method and ease of le...

PRAYER BEFORE CLASS Holy Spirit, Divine Creator, true source of light and fountain of wisdom! Pour forth your brilliance upon my dense intellect, dissipate the darkness which covers me, that of sin and of ignorance. Grant me a penetrating mind to understand, a retentive memory, method and ease of learning, the lucidity to comprehend, and abundant grace in expressing myself. Guide the beginning of my work, direct its progress and bring it to successful completion. This I ask through Jesus Christ, true God, and true man, living and reigning with You and the Father, forever and ever. Amen.  UST General Santos School of Health Sciences ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY Unit 13: The Urinary System Course Content 13.1. Urinary System Physiology 13.1.1. Urine Formation and Characteristics 13.3. Diseases of the Urinary System relevant to the Philippines 13.4. Diagnostic Tests for Urinary Disorders relevant to Medical Technologists Unit Intended Learning Outcomes: At the end of the unit, the student must be able to: Explain the urinary system works in the normal state and how it is affected in the presence of a pathophysiologic state. Discuss the different physiological tests and procedures to determine diseases/disorders associated with the urinary system. Apply the knowledge gained about the urinary system to actual health situations Formative Assessment: GUESS THE WORD SOMIOSO Formative Assessment: GUESS THE WORD RUTBALU BARPTOEINOSR Formative Assessment: GUESS THE WORD YIKSDEN Formative Assessment: GUESS THE WORD UMRLUGOLSE Overview of the Urinary System Overview of Urinary System Two (2) kidneys Two (2) ureters Urinary bladder Urethra Each kidney filters a large volume of blood Wastes from the blood are collected and form urine Functions of the Urinary System Functions of the Urinary System 1. Excretion 2. Regulation of blood volume and pressure 3. Regulation of blood solute concentrations 4. Regulation of extracellular fluid pH 5. Regulation of red blood cell synthesis 6. Regulation of vitamin D synthesis Urinary System Function: Excretion Kidneys filter waste products from the blood Fluid and waste are captured by an extensive network of tubes found throughout the kidney ○ Large molecules = remain ○ Smaller molecules & ions = enter the filtered fluid BLOOD → URINE Urinary System Function: Regulation of blood volume and pressure Hydration status: determines how much urine will kidneys produce ○ large volume: dilute urine ○ small volume: concentrated urine Through urine production → regulation of blood volume → blood pressure Urinary System Function: Regulation of blood solute concentrations Kidneys help regulate the concentration of major ions Urinary System Function: Regulation of extracellular fluid pH Kidneys secrete variable amounts of H+ to help regulate the extracellular fluid pH Urinary System Function: Regulation of red blood cell synthesis Kidneys secrete erythropoietin (EPO) → stimulates the synthesis of RBCs in red bone marrow Urinary System Function: Regulation of vitamin D synthesis Kidneys play an important role in controlling blood levels of Ca2+ by regulating the synthesis of vitamin D  Renal cortex: ○ outer region ○ Location for the blood-filtering structures  Renal medulla: ○ inner region ○ composed of renal pyramids (cone-shaped structures) collection of tubes and ducts that transport fluid throughout the kidney and modify it into urine NEPHRON Functional unit of the kidney 1.3M nephrons distributed throughout the cortex and medulla of each kidney NEPHRON 1. Renal corpuscle (glomerulus + bowman’s capsule) 2. Proximal convoluted tubule (PCT) 3. Loop of Henle 4. Distal convoluted tubule (DCT) Renal corpuscle - filters blood PCT - returns filtered substances to blood LoH - helps conserve water and solutes DCT - rids blood of additional wastes CD - carries newly formed urine from cortex to medulla Urine Production Glomerular Filtration Tubular reabsorption Tubular secretion  Kidney sorts substances from the blood either for removal in the urine or return to the blood  Urine Production 1 - Glomerular filtration Secreted: solutes 2 - Tubular reabsorption 3 - Tubular secretion Reabsorbed: solutes water Filtration Driving force: blood pressure ○ Forces fluid and small molecules out of the blood (only those small enough to fit through the filtration membrane) Filtered fluid: filtrate Filtration First step in urine production All blood components except blood cells and most proteins can leave the capillaries and enter the Bowman capsule as filtrate Filtration Importance of filtration: indicated by large percentage of cardiac output or blood, sent through the kidneys each minute ○ Renal Fraction (12% to 30%) Several measurements of filtration can serve as indication of proper kidney function Renal blood flow rate = Cardiac output x renal fraction Renal plasma flow rate = (Renal blood flow rate) x Plasma (0.55) Glomerular filtration rate (GFR) = Renal plasma flow rate x Filtration fraction (0.19) Filtration Filtration Membrane Made up of: 1. Fenestrated glomerular capillaries 2. Basement membrane (between capillary wall and visceral layer of the Bowman capsule) 3. Podocytes of the visceral layer of the Bowman capsule These components prevent molecules larger than 7 nm in diameter or those having a molecular mass ≥ 40,000 daltons from passing through Filtration Filtration Filtration Filtration Tubular Reabsorption Transport of water and solutes from the filtrate into the blood RECALL: OSMOSIS is the movement of _____ toward solutions with higher solute concentrations Tubular Reabsorption Critical in preventing the body from becoming overly dehydrated and deficient in important materials The filtrate leaves the lumen of the Bowman capsule → proximal convoluted tubule → loop of Henle → distal convoluted tubule → collecting ducts Tubular Reabsorption Tubular Reabsorption: PCT Tubular Reabsorption: PCT Proximal Convoluted Tubule: site of the majority of reabsorption Reabsorption of most solutes: diffusion of Na+ into the cells of PCT  Tubular Reabsorption: Loop of Henle Descending limb of the Loop of Henle: thin segment Simple squamous epithelium Highly permeable to water  Tubular Reabsorption: Loop of Henle Descending limb Ascending limb of the Loop of of the Loop of Henle: thin Henle: thick segment segment Simple Simple squamous squamous → epithelium simple Highly cuboidal permeable to Impermeable water to water and solutes Tubular Reabsorption: DCT and CD Distal Convoluted Tubule & Collecting Duct K+ and H+ are reabsorbed here ○ Reabsorption under hormonal control Anti-Diuretic Hormone (ADH) ○ (+) ADH → reabsorption of water ○ (-) ADH → impermeable to water Tubular Secretion Reabsorption in reverse Movement of non-filtered substances* from the blood to be eliminated in the filtrate * toxic byproducts of metabolism and drugs or molecules not normally produced by the body Tubular Secretion Hydrogen ions are secreted into the lumens of the proximal and distal convoluted tubules Secreting H+ → blood pH stays in its normal range → does not become too acidic  What are the organs of the urinary system? Functions of the urinary CHECKPOINT system? Steps of Urine Formation? Urine Movement Urine Flow Micturition reflex  Kidneys ⬇ Ureters ⬇ Bladder ⬇ Urethra Recall: What is the epithelium of the bladder? What is the function of that epithelium?  Micturition reflex Urinary bladder can stretch to hold 1L of urine (max) ○ Discomfort = ≥ 500 mL Capacity to distend due to 3 factors: 1. Wall of the UB contains large folds which unfold to enlarge the lumen 2. Transitional epithelium 3. Smooth muscle wall of the UB (except trigone) stretches to accommodate fluid  Micturition reflex Urination = micturition Micturition reflex is activated when the urinary bladder wall is stretched as urine fills the urinary bladder  Micturition reflex Urine filling bladder → stretch receptors → action potentials AP carried by sensory neurons to sacral segments of spinal cord In response → smooth muscle to contract (detrusor) → external urethral sphincter to relax Urine flows while EUS is relaxed References VanPutte, C. L., & Seeley, R. R. (2020). Seeley's anatomy & physiology. (12th ed.). New York, NY: McGraw-Hill Thank you!  UST General Santos School of Health Sciences ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY Unit 13: The Urinary System Dominican Blessing May God the Father bless us May God the Son heal us May God the Holy Spirit enlighten us Give us eyes to see with, ears to hear with, hands to do the work of God with, feet to walk with, and mouth to preach the word of salvation with; And may the angel of peace watch over us, and lead us at last by the Lord’s gift of the kingdom. Amen.