GU and Renal Disorders ConceptsElimination- Filters waste and stores in bladderPerfusion- Regulates BP; Produces erythropoietin -RBC productionFluid and electrolyte balance- Volume controlled by diluting or concentration urineAcid-base balanceLower Urinary System Review-Expected Normal As pressure (from urine) builds in the bladder, the micturition reflex is triggered. This allows you to pee.oControl (Continence)oPurposeful RetentionoFree of infection /discomfort-Requires oIntact muscle oIntact nerve connectionsoCognitive awareness-Acute /chronic problems affect storage or elimination of urineUreters – tubes carry urine from kidneys to the bladderBladder – Sac-like hollow organ that stores urine. walls stretch to hold urineUrethra -tube from bladder to outside of the bodyUrinary meatus - outlet The Nephron (Functional Unit of Kidney)-Glomerular filtrationoFluid filters from blood oEnters Bowman’s capsuleoDoesn’t allow bigger molecules through(protein)-Tubular reabsorption-Tubular secretionNephron Filtration-Proximal convoluted tubule – highly coiled, drains Bowman’s capsule and where almost complete absorption of nutritionally important substances takes place.The loop of Henle – thin loop-like long structure, reabsorbs water and ions from the urine and plays a role in the concentration of urine.Distal convoluted tubule – regulates potassium, sodium and pH and where further dilutionof the urine takes place.Collecting tubule – joins with several tubules to collect the filtrate and where final sodium regulation takes place.
Reabsorption: 65-85% of electrolytes (Na, K, Cl, HCO3) and nutritional substances (glucose, amino acids, lactate, vitamins)Renal Threshold- substance (glucose) appears in urine because it has reached the transport maximum (320 mg/min)Secretion: excretes organic anions and cations, end products of metabolism (ex: urate, oxalate) also end products of drugs (ex: penicillin, aspirin, morphine)Renal System Functionso1. Regulation of ion concentrationso2. Regulation of blood volume and blood pressureo3. Stabilization of blood pH (Acid-Base)o4. Conservation of nutrientso5. Elimination of organic molecules and toxinso6. Synthesis of calcitriolThe kidneys regulate the composition of body fluids by balancing the levels of the key electrolytes.They secrete or absorb these electrolytes to maintain the desired level within the body.The volume of body fluids is controlled by diluting or concentrating the urine.--Maintains volume/composition of body fluids within normal rangesoVolume of body fluids controlled by diluting or concentrating urineoClears waste- Nitrogen waste from protein metabolismoMaintaining acid-base and electrolyte balance--Regulates blood pressure: Renin-Angiotensin-Aldosterone System--Regulates RBC production- Erythropoietin --Regulates vitamin D activation- helps maintain/regulate calciumObstruction/Stasis-Anatomic or functional defect interferes with urine flow-Usually in urethra or meatus!