Urinary System Quiz

Clinical Diagnostic Module: Urine Analysis

• The module covers urine analysis, focusing on its clinical diagnostic applications.
• The presenter is Professor Eman Kandeel, and email address is provided.
• The presentation is from Nahda University, Beni Suef, Egypt, and is dated Issue 1/2018.

Code of Conduct

• Students should switch off their mobile phones.
• Students should smile.
•   Students should show respect for each other.
•   Students should strive to be on time.
• Students should concentrate on the topic being discussed.
• Students should value differences.

Intended Learning Outcomes

• Students will learn the fundamentals of urine analysis.
• Students will learn important notes on urine sampling.

Content

• Topics covered include urine formation, composition, factors impacting it, collection and preservation methods, different types of specimens, and physical and chemical examination procedures.

Urinary Tract

• The urinary tract consists of a pair of kidneys, two ureters, a urinary bladder, and urethra.
• Each kidney contains 1.3 million nephrons.
• Each nephron has glomeruli, Bowman's capsule, proximal convoluted tubule, Henle's loop, distal convoluted tubule, and a collecting duct.

Urine Formation

• Presentation includes diagram of nephron and its different parts.

Urine Composition

• Normal urine composition consists primarily of water (about 95%), urea, creatinine, uric acid, and electrolytes.
• Abnormal constituents can include glucose, protein, bile pigments, blood cells, casts, parasites, and bacterial microbes.

Factors Affecting Urine Composition

• Diet and nutritional status play a role.
• Body metabolism is a key factor.
• Kidney function affects composition.
• Contamination by microorganisms (bacteria or pathogenic microflora) affects composition.

Collection and Preservation of Urine Specimen

• Proper urine collection is crucial.
• Disposable plastic or coated paper containers are used, often with lids to minimize contamination.

Types of Urinalysis Specimens

• First morning specimen: Highly concentrated urine collected during the first urination of the day. Good for nitrite and protein.
• Random specimen: Convenient specimen collected at any time during the day. Most commonly used. Good for chemical screening and microscopic examination.
• Second voided specimen: First morning specimen is discarded and the next one collected and tested. Good for glucose level.
• Postprandial specimen: Collected two hours after a meal. Good for assessing glucose levels.
• 24-hour specimen: Collected within a 24-hour period. Vital for quantitative tests (e.g., protein).
• Mid-stream specimen: Collected from the middle portion of the urine stream. Used for routine urinalysis and bacteriological urine culture.
• Clean catch specimen: Used for microbial culture and routine urinalysis. Specimens collected using the clean-catch method.

Procedure for 24-hour Urine Collection

• Instruct the patient to empty their bladder and discard the initial urine at the start of the 24-hour period.
• Collect all urine produced over the next 24 hours, including the urine voided at the end.
• Store the collected urine with preservative, and label appropriately (test order, patient name, time of collection).

Preservation of Urine Specimen

• Examine the urine as quickly as possible after collection.
• Long standing degrades urine quality.
• Storage at room temperature leads to bacterial growth (urea breaks down to ammonia, impacting pH), calcium and phosphate precipitation, oxidation of urobilinogen, and destruction of glucose.

Types of Examination in Routine Urinalysis

• Physical Examination: Volume, color, odor, appearance, pH, specific gravity.
• Chemical Examination: Glucose, protein, ketones, bilirubin, urobilinogen, blood, nitrite, leukocyte esterase, melanin.
• Microscopic Examination: WBCs, RBCs, epithelial cells, casts, bacteria, yeasts, parasites, crystals, artifacts.

Categories of Urine Tests

• Screening tests: Only indicate presence or absence of substances (positive or negative).
• Qualitative tests: Accurately determine the substance.
• Quantitative tests: Measured in milligrams per deciliter (mg/dL), grams per deciliter (g/dL), or per liter (L). Require a 24-hour urine sample.

Physical Examination of Urine

• Urine volume: Dependent on intake and other factors (environmental, dietary, activity levels). - Polyuria is greater than 2.5-3 liters per day and is usually caused by large fluid intake, diuretics, alcohol, or issues with urinary tract reabsorption in conditions like diabetes. - Oligourea is less than 400 ml per day which can be caused by several conditions. - Anuria is less than 50 ml per day and is usually caused by very high heat, excessive sweating, and significant dehydration.
• Normal values are important to consider.

Urine Color

• Normal urine color ranges from straw yellow to amber.
• Color variations can indicate various conditions.

Urine Appearance/Transparency/Clarity

• Fresh urine should be clear and transparent.
• Long-standing urine may become cloudy.

pH Determination

• pH measures acidity, neutrality, or alkalinity.
• Normal pH for urine is between 5.0 and 7.0.

Specific Gravity of Urine

• Ratio of weight of urine to the same volume of water.
• Normal value is 1.016 to 1.022.

Chemical Analysis of Urine

• Glucose presence is determined.
• Other sugar levels are also checked.
• Physiological (e.g., after high-carbohydrate intake) and pathological (e.g., diabetes mellitus) reasons for glucose in urine are discussed.

Pathological Glycosuria

• Diabetes mellitus: A primary cause of abnormal glucose levels in urine.
• Other endocrine disorders: Hyperthyroidism, hyperadrenalism, hyperpituitarism, pancreas problems.

Urine Test Normal Values and Indicators

• Shows normal and abnormal values for various urine tests.

Dipstick Chemical Analysis

• Diagnostic tool using plastic strips with different colored squares.
• Colors are compared with a chart to determine the presence and concentrations of substances.

Microscopic Urinalysis

• Examines urine under a microscope to visualize cells and other components not easily seen with a dipstick.
• Different components in urine are checked (RBCs, WBCs, epithelial cells, casts).

Hematuria (RBCs)

• Presence of red blood cells in urine.
• Can be gross (visible) or microscopic (requires a microscope).
• Various causes including glomerular problems, tumors, stones, or urinary tract issues.

Pyuria (WBCs)

• Abnormal number of white blood cells in urine, often a sign of infection.
• Usually, granulocytes. Normal value is less than 2-5 WBCs/hpf.

Epithelial Cells

• Cells lining the renal tubules that can be found in urine.
• Increased numbers often indicate tubular damage.
• Normal value is less than 15-20 squamous epithelial cells/hpf.

Casts

• Cylindrical structures formed in the kidney tubes and found in urine under certain conditions.
• Can consist of cells or substances like protein.
• Different types of casts exist (e.g., red blood cell casts, white blood cell casts).

Crystals

• Solids formed from chemicals in urine.
• Normal to see a few small crystals.
• Large crystals or abnormal types can be problematic and potentially related to kidney stones.

Summary of Urine Analysis

• Urine analysis is crucial in detecting and assessing various diseases and disorders.
• Different tests used and what they can show are summarized.

Quiz Time

• A quiz section was presented, but the specific questions aren't included in the provided text.

Test your knowledge/Question

• A sample question/test is provided, asking about the significance of a high pus cell count (greater than 100) in urine.

Test your knowledge about the urinary system with this quiz! Explore key concepts such as components of the urinary tract, nephron functions, and urine collection practices. Perfect for students studying anatomy and physiology.