Physiology of kidney and urinary system compatibility mode

sinh lý thận hay cho sinh viên.tài liệu tiếng anh Physiology of kidney and urinary system compatibility mode sinh lý thận hay cho sinh viên.tài liệu tiếng anh Physiology of kidney and urinary system compatibility mode sinh lý thận hay cho sinh viên.tài liệu tiếng anh Physiology of kidney and urinary system compatibility mode

Kabul Medical University Physiology Department Physiology of Kidney & Urinary System Prepared by: Asso Prof f Dr Mohammad Amin Frotan 1388 Function of The Kidney z z Control of the level of the substances in the blood Filtratiosn of the blood from waste product product – – z Endocrine Function: – – – z z Exp: Urea, Createnin, Urinc Acid, Bilirubin, etc Drugs, toxin… Renin: Blood Pressure Control Erythropoitin: stimulant is mainly hypoxia 1.25 dihydroxyvitD3 Regulation water and electrolyte balance Gluconeogenesis Gluconeogenesis Urinary System Physiology Anatomophysiology of the Urinary System Kidney Pelvis Ureteropelvic Junction Ureter Ureterovesical Junction Urinary bladder Prostate Urethra Anatomophysiology of the Kidney Minor Calyces Major Calyces Cortex Medulla Pelvis Ureteropelvic Junction Ureter Lobe z z Renal Blood Flow 22% of Cardiac Output Renal Artery: – – – – – – – z Segmental artery Interlobar arteryy Arcuate artery Interlobular artery Aff Afferent t artery t Glomerular capillaries Efferent artery Peritubular capillary (and vasa recta in juxtamedullary nephrones) The Same are Veins z C Consists i t off : – THE NEPHRONE Glomerule: z z z z – Afferent Artery Glomerular Capillary Efferent Artery Bowman’s Capsule Tubule: z z Proximal Convulated Tubules Loop of Henle: – – z z Distal Convoluted Tubules Collecting Tubule: – – z Descending Limb z Thick Segment z Thin Segment Ascending Limb z Thick Segment z Thin Segment Cortical Medullary Collecting Duct Mi t ti Reflex Micturation R fl z Thus the Th th micturation i t ti reflex fl is i a single i l complete cycle of: 1- Progressive and rapid increase of pressure pressure 2- a period of sustained pressure 3- Return of the pressure to the basal tone of the bladder Intrave esicle Pres ssure (Centriimeters of water) 40 Micturation Contraction 30 20 10 0 400 100 200 300 Volume (mililiters) aves Acute Prressure Wa (caused by mictura ation reflex x) Micturation Reflex Facilitation or Inhibition of Micturition by the Brain z These centers include: Strong facilitative and inhibitory centers in the brain stem, 1stem located mainly in the pons 2- Several Centers located in the cerebral cortexs that are mainly inhibitory but can become excitatory z The higher centers normally exert final control of micturation as follows: 1- Keep the micturition reflex partially inhibited, except when micturation i t ti is i desired d i d 2- Can prevent the micturation by continual tonic contraction of external sphincter until a convenient time 3- When it is time to urinate the cortical centers facilitate the sacral micturition centers and at the same time inhibit the external sphincter Facilitation or Inhibation of Micturition by the Brain z Voluntary Urination: – – – – – – Voluntarily contraction of the abdominal muscles increase the pressure of the bladder Stimulates the stretching receptors Excites micturation reflex I hibit the Inhibits th external t l sphincter hi t Ordinarily all the urine will be emptied, with rarely more than 5-10ml left in the bladder Abnormalities of Micturation z Atonic Bladder: Caused by destruction of sensory nerve fibers from the bladder to the spinal cord, the persons looses bladder control (Overflow incontenance or Paradoxical incontinence) incontinence) other Exp: Tabetic bladder in Tabes dorsalis Abnormalities of Micturition Automatic Bladder: caused by spinal cord damage above the sacral region region (periodic but ananounced bladder emptying occur) In some patient scratching or tickling of the genital area due to full urinary bladder urination still can be controlled Ab Abnormalities liti off Micturition Mi t iti z (U (Uninhibited) b ted) Neurogenic eu oge c Bladder: adde caused by lack of Inhibitory signals from the Brain,, therefore facilitative impulses so excites the sacral centers that a small amount of urine can excites micturation reflex, there by Promoting frequent q micturation) ) : Excretion Control of H Level By its level in the body fluid: :Excretion Bicarbonate Buffer system H Cl H HCO3 H H2CO3 + HPO4 Na CO2 10% free NH3 Glutaminase Glutamin Acid NH3 + NH4+ Cl H 2O CO2 H H2PO4 H2CO3 + + HCO3 H Acidosis Ammonia Buffer system Na Na CO2 Phosphate Buffer system H 2O NaH2PO4 NH4Cl Acid Importance of Ammonia Buffer System NH3 Cl + NH4 = NH4Cl H = HCl (th (three d defense f liline ffor A Acid-Base id B C Control) t l) Acid-base Control 1: Chemical Acid Acid-base base Buffer System of the body fluid (Act in second) 2: Respiratory System (Act in minutes) 3: The Kidneys: (Act in hours or days but powerfully & maintain up to the end ) b excreting by i acidic idi or alkaline lk li urine i (up ( to 500mosmol 00 l Acid A id or Alkali) Alk li) PH off U Urine i PH of body fluid: 7.4 H+ Daily Acid Production H+ PH or Urine: 4.5 - level Control of Cl Related to the bicarbonate level Cl Cl HCO3 HCO3 Effect of Acidosis and Alkalosis Acidosis Depression of CNS Disorientation Coma Death Alkalosis Over excitability of PNS & CNS Limbs Muscle Tetany Respiratiory Musl Tetany Death Effect of Acidosis and Alkalosis K/H exchanges effect resting membrane potential of a neuron H In Acidosis K - - - - - - Hyperpolarization In Alkalosis H K ++ +++ +++ +++ +++ +++ +++ + H More excitable [...]... Mechanism of Function of the Nephron Filtration Reabsorption Excretion Blood Flow of the Kidneys 12-30% of Cardiac Output(5600ml/min) Pressure in different parts of the nephrone (mmHg) 60mmHg g 18 10 18mmHg 13mmHg 10mmHg 0 Diameter of the holes Glumerolar Membraen and its Selective Permeability Negativity of the basal memb Basal membrane Endothelial Epithelium 8 nm Protein = 1/240 Glumerolar Filtrate and. .. l Filtration Fil i Rate R Amount of glomerular filtrate/min: Definition: Factors Affect the GFR: Blood flow of the kidney Aff art constriction Eff art Eff art constriction Glomerular Pressure Concentration, Importance of GFR Regulation GFR GFR Ab Absorption ti off unnecessary substances b t GFR Excretion of necessary substances GFR depends on diameters of afferent and efferent arterioles Glomerulus... Mechanism of GFR I: In Case of Hypotension andRegulation: decrease in GFR Na & Cl GFR Tubular flow 1: Aff art Vasodilator Mechanism:absorption Aff art dilatation 2: Eff art Vasoconstrictor Mechanism: GFR Na & Fluid Absorption Stimulation of Macula Densa Aldosterone Level of Na & Cl Stimulation of Macula Densa Angiotensin Activation Eff art Constriction 1: In Case of Hypertension Myogenic Reflex Increase of. .. Rate 8% Reabsorption & Secretion in the Tubules U x V Plasma Clearance (C): C P U = Level of s in urine V = Rate of Urine Flow P = Level of s in plasma C of urea Inulin (Polysaccharide) GFR = C X X 18.2 0.26 125 of inulin x 1 ml/min x 1 ml/min 1 = 70ml/min = 125ml/min Baroreceptors Control C t l off Osmolarity O l it off the th Body B d X Fluid Σ Volume receptors Aldosterone ADH Osmoreceptor Factors ANF... Aff art constriction Σ Effect of 0 stimulation Weak Stimulation 1: on Renal Blood Flow and GFR: 10-30% Temporary Strengthen stimulation 2: Renin Secretion: long term 3: Na absorption: Out put 0 >20-30min GFR by the effect sympathetic is important in cases of acute disturbances di t b such h as brain b i ischemia i h i or severe hemorrhage h h Autoregulatory escape Eff t off Blood Effect Bl d Pressure... >50mmHg ) (> 200mmHg ) Urine Output 7 times of urine Output 0 Reabsorption & Secretion in the Mechanism Tubulesof Transportation through the Cell memb O Osmosis i 1: Passive Facilitated Diffusion Simple Diffusion Primary 2: Active Secondary Massive Sodium Co-Transport Sodium Counter-Transport Pinocytosis Phagocytosis Reabsorption Ability of Different Parts of the Tubules P i i l cells Principle ll Na... NEPHRONE THE NEPHRONE Nephrones Structure of the Nephrone p Glumerole Juxtaglumerolar Complex Proximal Convoluted Tubule Distal Convoluted Tubule Loop of Henle Collecting Duct Peritubular Cappilary REGIONAL DIFFERENCE IN NEPHRONE STRUCTURE z Cortical Nephron p – – z Short Loop of Henle Peritubular capillary network Juxtamedullary Nephron (20-30%): – – Long loop of Henle Vasa recta z z Juxtaglomerular... Prostaglandins, Kinins, Dopamine (low dose) Efferent arteriole Glomerular filtrate Eff Art constriction Angiotensin II (low dose) ØGFR Aff Art constriction Ang g II ((high g dose), ), Noradrenaline (Symp nerves) Eff Art dilatation Angiotensin II blockade R i Renin Angiotensinogen Aldosterone Converting Enzyme Angiotensin-I Angiotensi-II Aldosterone Juxtaglomerular Complex (Stable in 75 - 160mmHg of blood... Principle ll Na Aldosterone K+ K+ Intercaleted ((Brown ) cells J G C 65% Diluting seg J G C Lat Distal tub H+ ADH others X Urea H20 X Urea X H20 ADH X Na H20 H20 X Urea H20 Urea Urea H+ Acidic Reabsorption of different substances in the Tubules H2O Na Na glu AA glu, S glu P AA Aceto acetate N Vitamins Proteins Cl Proteins Ca H HCo3 Mg H2Co3 HCo3 CO2 OH CO2 H2O Createnin X Urate Urea 50% 50% Tubular Load