Renal and Urinary System PDF

[**Chapters 22 & 23: Renal Disorders and Urological Disorders**](https://uttyler.instructure.com/courses/42296/files/9844678?wrap=1) **Kidney Function** **Filtration:** - Removes metabolic wastes (urea, uric acid, ammonia, creatinine) - Removes drugs and other foreign materials from the body...

[**Chapters 22 & 23: Renal Disorders and Urological Disorders**](https://uttyler.instructure.com/courses/42296/files/9844678?wrap=1) **Kidney Function** **Filtration:** - Removes metabolic wastes (urea, uric acid, ammonia, creatinine) - Removes drugs and other foreign materials from the body **Reabsorption:** - Regulates water and electrolytes balance - Maintains acid-base balance (excretes hydrogen ions and reabsorbs bicarbonate) **Secretion:** - Secretes **erythropoietin** (stimulates red blood cell production) - Activates **vitamin D** (essential for calcium absorption) - Secrete Renin and thus regulate blood pressure through the renin angiotensin aldosterone system (RAAS) **Hormones Involved in Kidney Function (Reabsorption)** **Antidiuretic Hormone (ADH):** - Secreted by the posterior pituitary - Controls water reabsorption - Higher amounts of ADH: Small concentrated urine and more fluid kept in body - Lower amounts of ADH: Large amounts of dilute urine & more fluid leaving the body. **Aldosterone:** - Secreted by the adrenal cortex - Controls sodium and water reabsorption **Renal Blood Flow impacts GFR** Glomerular Filtration Rate (GFR): - GFR measures renal blood filtered per unit of time. - It\'s the best estimate of kidney function. - Filtration depends on hydrostatic pressure in the glomerular capillary. - High GFR (above \>90 mL/min): Kidneys are functioning well. - Low GFR (below \ - B/P closely related to kidney function **Renin-Angiotensin-Aldosterone System (RAAS)** **RAAS:** Triggered by any decrease in blood flow/perfusion to the kidney (typically from low blood pressure) - Activated by decreased kidney perfusion or low sodium levels. - **Renin** starts the process that activates **angiotensin** and **aldosterone**: a. **Angiotensin** causes vasoconstriction (increases blood pressure). b. **Aldosterone** increases sodium and water reabsorption (increasing blood volume and pressure). **Key Lab Indicators of Kidney Function:** - **GFR (Glomerular Filtration Rate):** Best measure of kidney filtration efficiency. - **Urine Creatinine Clearance (CrCl):** Assesses how well kidneys are clearing creatinine. - **Serum (blood) Creatinine:** High levels indicate poor kidney function. - **Blood Urea Nitrogen (BUN):** Measures nitrogenous waste in the blood. **Kidney (Renal) Dysfunction** In kidney dysfunction, several issues arise: - **Metabolic waste buildup**: Leads to uremia, anemia, and confusion. - **Urine production drops**: Resulting in oliguria (low urine output) or anuria (no urine). - **Electrolyte imbalances:** a. Hyperkalemia: Excess potassium, leading to cardiac problems. b. Metabolic acidosis: Poor H+ ion excretion. i. Erythropoietin secretion decreases: Leading to anemia. ii. Vitamin D activation reduces: Resulting in hypocalcemia. **Kidney (Renal) Dysfunction** - **Filters the blood of waste**: The kidneys remove metabolic waste products, such as urea, uric acid, and creatinine, from the blood. - **Produces urine**: The kidneys produce urine at an approximate rate of 30 mL per hour, which helps excrete waste from the body. - **Secretes renin**: In response to poor perfusion (low blood flow), the kidneys release renin to help regulate and increase blood pressure. - **Secretes erythropoietin**: This hormone stimulates the production of red blood cells in the bone marrow. - **Excretes excess hydrogen ions (H⁺):** The kidneys help maintain the body\'s acid-base balance by excreting excess hydrogen ions. - **Excretes excess potassium (K⁺):** The kidneys regulate potassium levels by excreting excess amounts. - **Synthesizes a component of vitamin D**: The kidneys activate vitamin D, which is necessary for calcium absorption in the intestines. **Common Renal Diseases (INFECTIONS/INFLAMMATION OF KIDNEYS)** 1. **Pyelonephritis** (Kidney infection): - Typically caused by bacterial infections (most commonly **E. coli**). - Symptoms include flank pain, high fever, chills, confusion, N/V, hematuria (blood in urine). 2. **Acute Glomerulonephritis AG:** - Often a result of post-streptococcal infection (beta-hemolytic strep). - Symptoms develop 7-21 days after infection and include edema, oliguria, hematuria (Dark urine), proteinuria, hypoalbuminemia. 3. **Nephrotic Syndrome:** - Damage to the glomerulus, often due to diabetes (diabetic nephropathy). - Results in proteinuria (loss of protein in urine), edema, and hypoalbuminemia, SAME as **AG** 4. **Polycystic Kidney Disease (PKD):** - Genetic disorder causing cysts in kidney tissue. - Cysts impair kidney function, leading to hypertension and kidney stones. - Symptoms: pain from pressure of fluid in the cysts, renal calculi (kidney stones), hematuria. **Acute Kidney Injury (AKI) vs. Chronic Renal Failure (CRF)** - **AKI**: - Sudden onset, reversible with treatment. - Causes: Poor perfusion, nephrotoxins, or urinary blockage. - Symptoms: Oliguria, hyperkalemia, fluid overload, and metabolic acidosis. - **CRF**: - Slow onset (over months or years), irreversible. - Common causes: Diabetes mellitus, hypertension, glomerulonephritis, and PKD (Polycystic kidney disease) **AKI Phases:** - **Initial:** From initial insult (prerenal, intrinsic/intrarenal, or postrenal condition that disrupts kidney function) to symptoms - **Oliguria:** low GFR, lack of urine output, fluid overload - **Diuresis:** (beginning to recover) large volume of unconcentrated urine that does not yet contain all the waste products it should - **Recovery:** healthy nephrons take over function of damaged nephrons; kidney function resumes **Fluid Volume and AKI** - Causes of AKI: Poor perfusion from low fluid volume - such as in dehydration and shock - Symptoms of AKI -- Decrease ability to remove fluid or create urine leads to fluid volume overload: **Peripheral edema**, and **Pulmonary edema.** - **Stage 1:** kidney damage with normal or increased GFR (greater than 90 mL/min) - **Stage 2:** mild reduction in GFR (60 to 89 mL/min) - **Stage 3:** moderate reduction in GFR (30 to 59 mL/min) a. 50% nephrons functioning b. Decrease GFR, Increase serum creatinine and BUN c. Damaged nephrons undergo fibrosis - **Stage 4:** severe reduction in GFR (15 to 29 mL/min) - Must restrict dietary protein (difficulty removing nitrogenous waste) - Stage 5: kidney failure (GFR lower than 15 mL/min) - ESRD **Infections and Inflammation of the Bladder/Urinary Tract** 1. **Lower Urinary Tract Infections (UTIs):** - Commonly caused by E. coli from the bowel. - Symptoms include burning urination (dysuria), frequency, and urgency. 2. **Interstitial Cystitis** (Painful Bladder Syndrome): - Characterized by chronic pelvic pain, Dysuria (pain when urinating, full bladder urgency, and frequency) 3. **Urolithiasis** (Kidney Stones): - Formation of stones in the urinary system. - Symptoms: Severe flank pain, hematuria, fever, pyuria, painful urination and nausea. **Bladder Cancer** - Most common urological cancer. - Risk factors include cigarette smoking and exposure to organic chemicals. - Symptoms: Painless hematuria, frequent urination, and incomplete bladder emptying, burning urination.