Renal and Urinary System PDF
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This document covers the renal and urinary system, including kidney function, hormones involved in kidney function, and common renal diseases, which are crucial topics in human biology. It also discusses the importance of kidney function in maintaining overall health.
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[**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.