Renal Physiology PDF

RENAL SYSTEM & CONDITIONS Parts: 1. Renal Artery → supplies blood 2. Renal Vein → deoxygenated blood from kidneys 3. Renal Pelvis → receives urine from major calyces 4. Renal Cortex → outer layer of the kidney 5. Renal Medulla → filter liquid waste, retain fluid in case the body is d...

RENAL SYSTEM & CONDITIONS Parts: 1. Renal Artery → supplies blood 2. Renal Vein → deoxygenated blood from kidneys 3. Renal Pelvis → receives urine from major calyces 4. Renal Cortex → outer layer of the kidney 5. Renal Medulla → filter liquid waste, retain fluid in case the body is dehydrated, balance electrolytes, and eliminate extra acidity in the bloodstream. 6. Renal Pyramids → help with blood filtration and water concentration regulation within your kidneys CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024  7. Renal Papilla (Papillary Duct) → water reabsorption and electrolyte balance initiated in the collecting tubules. 8. Minor Calyx / Calyces → collects urine from that pyramid 9. Major Calyx → urine passes before continuing through the renal pelvis into the ureter. 10. Renal Lobule → combination of cortex & Medulla 11. Renal Sinus → fats deposits ; cushioning 12. Renal Columns → in between renal medulla 13. Renal Hilum → ureter opening ; entry and exit site for structures servicing the kidneys: vessels, nerves, lymphatics, and ureters. KIDNEYS (2) ➔ 1.2 - 1.3 L / min blood ➔ Location : Retroperitoneal organ ( at the back of peritoneum) ➔ Verbal Landmarks: T12 - L3 (R) is lower d/ t the (R) WAIT MO SI AIRA BEH ➔ Dermatomes: T10 -L1 ➔ COVERING : Renal Capsule ; fat ; anchors kidneys to floating ribs Nephroptosis ★★ ★★ ➔ Inferior displacement ; d/t atrophy of renal capsule ➔ BLOOD SUPPLY : “ARSI A CAGE PC AIR” 1. AORTA 2. RENAL ARTERY 3. SEGMENTAL ARTERY 4. INTERLOBAR ARTERY 5. ARCUATE ARTERY 6. CORTICAL RADIATING ARTERY 7. AFFERENT ARTERIOLES 8. GLOMERULAR CAPILLARIES 9. EFFERENT ARTERIOLES 10. PERITUBULAR CAPILLARIES 11. CORTICAL RADIATING VEINS 12. ARCUATE VEINS 13. INTERLOBAR VEINS CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024  14. RENAL VEINS Innervation: Sympathetic Nervous System (SIS) T10 -L1 (thoracolumbar outflow) Ax: Kidney Punch Test Palm on costovertebral angle (+) Pain KIDNEY THE NEPHRON ➔ Functional unit of the kidneys ➔ 800,000 -1,000,000 at birth ➔ Does not regenerate @ 40 y/o - ↓10 % Evert after 10 years - ↓10 % ➔ Glomerular Filtration Rate -125 mL/min PARTS: 1. Renal Capsule Bowman's Capsule - Glomerulus - Glomerulus. Tuft capillaries enclosed in the Bowman’s capsule ; filtration ; impermeable to sugar (Glycosuria) and proteins (proteinuria) ❖ Filtering unit of nephron ❖ Supplied by the Afferent A. ❖ Drained by the Efferent A. ❖ BM’ space collecting filtrates → PCT 2. Renal Tubule - reabsorption & secretion Long Tubules a. Prox. Convoluted Tubule → perm. to water b. Loop of Henele ❖ Thin Descending → perm.to water Aquaporin - 1 CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024  Luminal fluid becomes CONCENTRATED Remaining fluid will be reabsorbed at the loop ★★ ❖ Thin Ascending → H20 not permeable ; NACL reabsorption ❖ Thick Ascending →imprem. to all →Primary Site for NA reabsorption * Others : Ma, Ca, K ❖ Thick Ascending → imperm to water ; perm to electrolytes c. Dist. Convoluted Tubule ❖ Early → AKA “Diluting Segment” Imperm to water NCC -Na, Cl, constraporter Parathyroid Hormone (PTH) →Ca reabsorption ★★ ❖ Late → Site of ADS and ADH d. Cortical Collecting Duct e. Medullary Collecting Duct Collecting Duct ➔ Principal → Na reabsorption ; ADH -H2O reabsorption ➔ Intercalated Cells → Acid Secretion ; HCO3 transport Intercalated Cells ➔ Late DCT & Collecting tubules ➔ ADH dependent reabsorption of water ➔ Na reabsorption TYPE A: TYPE B: HCO3, K H,CL, Hydrogen (Bicarbonate & Potassium) renal cells Secretion ➔ Transfers of substances from tubules or / and blood to the luminal fluid. Outcomes: 1. H+ Secretion → control pH 2. Secretion of substances to be excreted. CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024 PCT LOOP OF HENLE DCT COLLECTING DUCTS ❖ Creatine ❖ UREA ❖ H→ H ❖ H ❖ Drugs → Drugs ❖ Urea ❖ NH4 → NH4 ❖ NH4 (amonia) ❖ K→ K ❖ Drugs URINE 95 % H2O 5 % WP 4-8 pH UROBILIN → gives pigment to urine → vegetation of RBC URINE FORMATION ★★ Ureters (2) ➔ Muscular tube that propels urine to the bladder ➔ Peristaltic contraction ➔ 10 inches ➔ MC Obstructed : 3 constrictions - renal pelvis, pelvic brim ; bladder wall CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024  Urolithiasis → urine color LOWER URINARY TRACT Urinary Bladder ➔ Temporary storage of urine ➔ 500 ml ★★ ➔ Location: directly behind the symphysis pubis ➔ When Empty (pyramidal) - pelvis ; full - (abdomen) ➔ Detrusor muscle (wall) smooth muscle wall of the bladder ★★ ➔ Sphincter Vesicae ★★ @ bladder neck ★★Micturition Reflex - S2 - S4 Stimulus : bladder distention Response: Detrusor muscle contraction ; relaxation of sphincter vesicae Urethra ➔ Single ➔ Terminal portion RS ➔ Sir Titus : ◆ Male: 7-9 inch (+) Prostate Gland ◆ Female: 2-3 inch ➔ Catalyst : ★★ ◆ Male: 8 inch (20cm) ◆ Female : 1.5 inch (3.8 cm )(UTI) ➔ 2 sphincters : ★★ ★ Internal Urethral Sphincter (INV)oluntary CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024  ★ External Urethral Sphincter (V)oluntary ➔ 3 parts of Male Urethra ★★ 1. Prostate → widest dilatable 2. Membranous → least dilatable 3. Penile → largest dilatable RENAL FUNCTIONS - Urine Formation & Excretion 1. Filtration of plasma → luminal fluid wastes ; glomerulus Urea →amino acids Creatine →muscle creatine Uric acid → nucleic acid Bilirubin →hemoglobin 2. Regulation of H2O & Electrolyte balance 3. BLOOD PRESSURE REGULATION (RAAS) 4. Regulation of Fluid Osmolarity → concentration of Solutes N - 290 mOsmoles/ L ★★ 5. Acid Base Regulation 6. Secretion, Metabolism, Excretion of Hormones 7. Gluconeogenesis → Glucose formation from other precursors prolonged fasting → Livers fxn. MICTURATIONS S2-S4 ❖ Sacral Plexus (S2-S4) Reflex - Toilet trained → higher brain center ❖ Stimulus: urine volume 300 ml ★★ ❖ Response : Detrusor Muscle : cxn Sphincter : relax / open ❖ Assisted by: abdominal cxn → ↑ Intra Abdo Pressure & Pelvic Pressure ❖ Voluntary Control → Contract EUS (External Urethral) ❖ Toilet Trained: 2-3 y/o ★★ INCONTINENCE ( FUSO) CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024  FUNCTIONAL URGE/OVERACTING STRESS OVERFLOW ➔ N bladder ➔ (+) incontinence ➔ (+) Sphincter & ➔ flaccid/ atonic ➔ (+) Recognize the without afferent Pelvic floor ms. bladder need to urinate but reason. weakness. ➔ Urine Left @ unstable to do so d/t ➔ (+) involuntary ➔ Intra abd bladder physical immobility. cxn of detrusor ms. Pressure ↓ ➔ (+) physical & ➔ MC: Old Age Sneeeze Overdistention environmental ★★ Cough ↓ bariiers. Exert Effort Urine Leak Child birth MC: Crede’s Maneuver MC: Kegel Exercise ★★ ★★ FILTRATION Glomerular Filtration Rate ★★ ➔ Rate of glomerulus filtering blood plasma per unit of the time N Males: 125 ml/ min N Females: 105 ml/min Ultrafiltrates : small substances + H2O Net Filtration Pressure (10mmHg) ★★ ➔ Based on STARLING FORCES NFP = Net Hydrostatic P - Net Oncotic P Oncotic Pressure ➔ Forced by proteins against capillary wall ➔ Main determinant Albumin ➔ Net Oncotic P : Glomerular OP - Bowman’s Space ➔ Net Oncotic P : 6 OP - BS OP 30mmHg OP mmHg Hydrostatic Pressure - 40 mmHG ★★ CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024  ➔ Force exerted by blood / fluid against capillary wall ➔ Main determinant of GFR ➔ Net - Hydrostatic P ➔ Glomerular HP - Bowman’s Spae 50 mmHg 10 mmHg 40mmhg -30 mmHg = 10 mmHg Filtration Marker - “ideal inulin” MC: Creatinine 2nd Best! ★★ ➔ Homeostatic Mechanism that maintains renal blood flow (RBF) & GFR ➔ Myogenic Mechanism ❖ ↑ Blood Flow ❖ ↑ GFR ❖ ↑ BP ➔ NACL concentration ➔ Macula Dense ↑NA Cl ↓ NA Cl → Nitric Oxide →dilate → ↑ GFR ➔ Adenosine → constrict → GFR STIMULUS : Low GFR High GFR Decrease BF Increase BF (stretchwall) RESPONSE : Dilate Afferent A. Constriction END: Constant RBF CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024 RAAS ➔ RENIN - ANGIOTENSIN - ALDOSTERONE SYSTEM ➔ Purpose: 1. Reg.BP ↓ 2. Activation of Angiotensin II Major vasoconstrictor ↑ Blood vol. Angiotensin II 1. Brain a. Hypothalamus b. PPG -post pituitary gland - ADH/ Arginine Vasopressin - Incr. H2O Reabsorption - Stimulates: Adrenal Cortex Aldosterone Incr. Na Reab Incr. H2O Reab Incr. K. Excretion “ I can do all things through christ who strengthen me” CARMINA P. MANALO PTRP BORD REVIEW FOR DECEMBER 2024