1030 UNIT 5 Additional questions

General Information

• PowerPoints are a general overview for note-taking during video lectures.
• PowerPoints do not cover all details required for the unit exam.
• Students are responsible for reading the textbook to understand the unit objectives.
• The unit objectives are the study guide, not the PowerPoint.
• Test questions come from the textbook (not the PowerPoint) and relate to the unit objectives.

Cerebrospinal Fluid (CSF)

Formation and Physiology

• CSF supplies nutrients & removes waste from the nervous tissue.
• CSF maintains intracranial pressure & cushions the brain & spinal cord.
• The meninges (Dura mater, arachnoid, pia mater) line the brain & spinal cord.
• CSF is produced by choroid plexuses in the brain ventricles.
• Approximately 20 mL of CSF is produced every hour.
• The normal volume of CSF is 90-150 mL (neonates 10-60 mL).
• Endothelial cells allow nutrient & waste exchange between plasma & tissues, protecting the brain.

Specimen Collection and Handling

• CSF collection is lumbar puncture, between the 3rd & 4th or 5th & 6th vertebrae.
• Opening pressure is recorded.
• Elevated pressure requires slow fluid removal.
• Specimens collected in 4 sterile tubes.
• Tube 1: Chemistry/serology tests (may be frozen).
• Tube 2: Microbiology tests (room temperature).
• Tube 3: Cell count (hematology) – refrigerate up to 4 hours.
• CSF is STAT.

CSF Appearance

• Report CSF color & clarity.
• Colorless/clear, cloudy, turbid, milky, xanthochromic, & bloody.
• Xanthochromic: pink, orange, yellow (due to RBC breakdown).
• Refer to Table 10-1 for detailed information.

Blood in CSF

• Even or uneven distribution of blood.
• Bloody (intracranial hemorrhage) = even distribution.
• Uneven = traumatic tap (highest concentration in tube 1).
• Xanthochromic indicates old blood.
• Red = traumatic tap, orange/yellow = old blood.

Cell Counts

• Normal adult CSF values: 0-5 WBCs/uL.
• Children's & neonate values can be higher, see table.
• RBCs in CSF are mostly due to the tap procedure.
• Refer to automation for standardized and precise cell counts.

Cell Counts - continued

• Use Neubauer chamber for manual cell count.
• Equation: (Number of cells counted x dilution) / (Number of squares counted x volume of 1 square) = cells/uL

Differential Count

• Differentiating cells in the CSF after total count.
• Stained smear or cytospin slide.
• Should show a monolayer cell distribution.
• Some labs report only mononuclear and polynuclear neutrophils; others report a 5-part differential.
• Use Cytocentrifuge to force cells onto a slide in a monolayer.
• Refer to Table 10-2 for number of cells to count based on chamber count.

Differential Count - Continued

• Evaluating different cell types in CSF to identify diseases (pleocytosis).
• Neutrophils (bacterial infections).
• Lymphocytes & monocytes (viral/tubercular/fungal or parasitic infections).
• See Table 10-3 for reference.

Mononuclear Cells

• Normal in low numbers (Viral, tubercular, fungi meningitis.)
• Reactive lymphocyes
• Dark-blue cytoplasm with clumped chromatin
• Plasma cells.
• HIV infection, multiple sclerosis, degenerative disorders.
• Monocytes/Macrophages typically counted together.
• Monocytes (blood) & Macrophages (tissue).
• Refer to different diagnoses for expected cell counts in the appropriate table.

Chemistry Test

• Tube 1 (Most common) for protein & glucose.
• Protein: 15-45 mg/dL (reference).
• Albumin, prealbumin, a-globoins, beta + gamma globulins.
• Decreased protein indicates CNS damage or leakage of the blood-brain barrier.
• Elevated: immunoglobulin production in the CNS or neural tissue degeneration. See Table 10-1 for detailed values and additional information.

Glucose

• Selectively transported
• Normal range: 60% - 70% of plasma glucose.
• Evaluate CSF glucose compared serum glucose within 2 hours.
• Decreased: bacterial (↑ WBCs), tubercular, & viral meningitis.
• ↑ glucose = ↑ serum glucose in 2 hours See Table 10-4 for more detailed information.

Microbiology Test

• Detecting organisms in CSF.
• Micro test takes 24 to 6 weeks, depending on the organism.
• CSF culture confirms results.
• Preliminary tests (gram stains & acid-fast stains, India ink, etc).
• Molecular testing (PCR) for quick identification in specific cases (like COVID)

Semen Analysis

Physiology

• Semen consists of four components: testes & epididymis, seminal vessels, prostate, & bulbourethral glands.
• Testes produce spermatozoa in the seminiferous tubules & mature in the epididymis.
• Seminal vessels produce most of the fluid, containing fructose.
• The prostate produces acidic fluid (acid phosphatase & citric acid) and is responsible for coagulation & liquefaction.
• Bulbourethral glands produce alkaline fluid.

Specimen Collection

• Proper collection is necessary for a valid fertility evaluation or vasectomy success.
• First portion is missing = ↓ sperm count & elevated pH.
• Last portion is missing = ↓ volume & ↓ sperm count.
• Specimen will need to be checked for liquefaction and clot.

Semen Analysis- continued

• Macroscopic (within 1 hour of collection).
• Appearance: normal = grayish-white & translucent; abnormally clear = low sperm; abnormally white = Increased WBCs; abnormally red/yellow - blood/urine
• Liquefaction: normal range 30-60 minutes. (>60 = ↓ prostatic enzymes)
• Volume: 2-5 mL (Refer to table for values for abnormalities)
• Viscosity: ranges from watery (0) to gel-like (4);
• pH: 7.2-8.0; (increased = infection) (decreased = obstruction)
• Microscopic Motility: assess forward & progressive movement. Assess 200 sperm per slide
• Use Neubauer chamber (1:20 dilution) to count sperm.
• Calculation for cells/uL: (Number of cells counted x dilution)/(Number of squares counted × volume of 1 square).
• Count in four corners and center of squares on hemacytometer.
• Calculate the % of sperm with particular motility. (i.e. progressive / slow / non-motile)
• Refer to abnormalities tables for reference values.

Additional Semen Analysis

• Sperm viability – use eosin-nigrosine.
• Seminal fluid fructose energy (≥ 13 umol/ejaculate).
• Anti-sperm antibodies
• Microbial (Chlamydia, Mycoplasma, Ureaplasma).
• Chemical test (α-glucosidase, free L-carnitine, zinc, citric acid, and glutamyl transpeptidase & prostatic acid phosphatase)

Synovial Fluid

Physiology

• Synovial fluid is a viscous liquid found in movable joints.
• It acts as a lubricant and reduces friction during joint movement.
• It is an ultrafiltrate of plasma, nonselectively filtering out large proteins.

Classifications

• Noninflammatory (e.g., osteoarthritis)
• Inflammatory (e.g., rheumatoid arthritis, lupus erythematosus)
• Septic (microbial infection)
• Hemorrhagic (trauma, tumors, coagulation deficiencies).

Collection and Handling

• Needle aspiration (arthrocentesis) is typically used to collect synovial fluid.
• Usual amounts vary by joint size. Normal knee fluid is typically <3.5 mL.
• Collect in tubes for chemistry, cytology, and microbiology.

Collection & Handling- continued

• Use EDTA for hematology, Green (heparin) for crystal/chemistry, and SPS(Yellow) for microbiology cultures.
• Correct procedures ensure accurate and appropriate testing.

Gross Appearance

• Color & Clarity (colorless/pale yellow to yellow, greenish, reddish, and creamy white).
• Clear, hazy, cloudy, and turbid (depending on cell presence/WBCs/RBCs)
• Viscosity (like egg whites)
• Polymerization of Hyaluronic Acid is key for mobility.
• Decrease polymerization: arthritis.
• Rate of production/reabsorption are constant for normal amount.

Hematology Test

• Cell counts (WBC & RBC).
• Differential count - automated or manual techniques.
• Differentiating cells (monocytes, lymphocytes, neutrophils, etc) to understand disease state possibilities in classification.
• Refer to table for normal (or expected based on sample category).

Seriological Test

• Related tests are performed on serum, but may be used as confirmation.
• Common causes of arthritis include rheumatoid arthritis (RA) and lupus erythematosus(LE).
• Lyme disease requires specific serum testing for Borrelia burgdorferi antibodies.

Chemistry/ Microbiology Test Results (specifics)

• Abnormal results will differentiate between exudate and transudate.
• Use of tables and appropriate tests needed for specific diagnosis.

Synovial Fluid Classifications Continued

• Crystal-induced origin: cloudy or milky; low viscosity.; WBC/mL (up to 100,000 uL) neutrophils (up to 70%); decreased glucose & elevated uric acid. Crystals present.
• Septic origin: cloudy; poor viscosity; WBC/mL (50,000 to 100,000 uL), neutrophils (over 75%), decreased glucose, positive culture & Gram stain.
• Hemorrhagic: cloudy red; low viscosity, WBC equal to blood, neutrophils equal to blood, normal glucose, & RBCs.

Crystals Identification

• Presence of crystals in synovial fluid is crucial in evaluating the cause of arthritis.
• Monosodium urate (MSU) crystals (gout).
• Calcium pyrophosphate dihydrate (CPPD) crystals (pseudogout).
• Hydroxyapatite, cholesterol, calcium oxalate, cortical steroids.

Crystal Examination

• Using a microscope for examining slides.
• Preparation of wet slides for crystal identification.
• Using special types of microscopy (such as polarized light microscopy) and techniques (such as staining) to identify different types of crystals.

Chemistry Test - Continued

• Glucose testing for inflammatory/infection/malignancy (low glucose = possible tuberculosis/rheumatoid, some malignancies, esophageal rupture)
• pH (<7.3) and adenosine deaminase (>40 U/L) can aid in diagnosis.
• Amylase = pancreatitis, esophageal rupture

Microbiology and Serology Tests (specifics continued)

• Cultures & Gram stains
• Acid fast and stains
• PCR
• Specific tests used to detect pathogens or specific bacteria, viruses, or fungal organisms for infections in joint cavities.
• Serologic tests used to detect antibodies often associated with autoimmune disorders (autoimmune diseases/ arthritis/ infections).

Seriological Test - Continued

• Determining the presence of inflammation.
• Commonly used tests are C-reactive protein and fibrinogen - can aid in diagnosis if infection or inflammation is suspected.

Seriological Test- Continued

• RA and LE are common autoimmune causes of arthritis.
• Serum for Borrelia burgdorferi antibodies important in Lyme disease.

Peritoneal Fluid

• Accumulation of fluid in the peritoneal membrane - ascites.
• Collecting fluid after peritoneal lavage.
• Causes: liver disorders (cirrhosis), bacterial infections (peritonitis), intestinal perforation.
• Diagnostic procedure (peritoneal lavage).

Peritoneal Fluid - continued

• Appearance (pale yellow/clear, turbid/bacterial infection, dark green/brown = bilirubin).
• Cellular examination- normal nucleated cells ( <500 cells/µL).
• Absolute neutrophil count >250 cells/µL or 50% of total WBC = possible peritonitis or cirrhosis.
• WBC = mesothelial cells, macrophages, malignant cells from various organs.

Additional Testing of Peritoneal Fluid

• Additional testing of peritoneal fluid can include glucose, amylase, BUN/creatinine, cultures, TB-cultures, gram stains, tumors, acid fast, tumor markers.

Bronchoalveolar Lavage (BAL)

• Method for examining lower respiratory tract in immunocompromised or airway/breathing problems.
• Using fiber optic scope for lavage inside the lung lobes.
• A sterile saline solution is used for lavage, then aspirated and sent out for testing.
• Collect specimen within 30 minutes.
• Should stay at room temperature.
• Count white and red blood cells in specimen (see detailed procedure)
• Cell counts & staining.

Cells Present in BAL (types, counts, significance)

• Macrophages, lymphocytes (CD4/CD8), neutrophils, eosinophils, ciliated columnar bronchial epithelial, squamous epithelial cells.
• Cell counts & proportions may indicate infection, inflammation, or other diseases (e.g., tumors).

Microbiology Test (BAL)

• Run cultures to identify pathogens (bacterial/fungal/viral).
• Quantification of pathogens in suspected cases is helpful to determine cause of illness.
• Special procedures are needed for suspected viral/fungal pathogens for accurate identification.

Cytology Test

• Examine cells for presence of unusual/malignant cells, inflammatory cells, or other pathogens.
• Evaluate for presence of sulfur granules, etc.

Amniotic Fluid

• Physiology: a clear fluid in the amnion surrounding the fetus.
• Functions of amniotic fluid = exchange of water and chemicals between the fetus and maternal circulation, cushion for the fetus during movements, regulates temperature, enables proper lung development.
• Volume changes over the course of pregnancy.
• High volume (polyhydramnios): can reflect fetal anomalies, or chronic health conditions.
• Low volume (oligohydramnios) : can reflect serious fetal conditions.
• Composition: water, electrolytes, proteins, waste products, cells.
• Composition analysis can help detect abnormalities.

Amniocentesis

• Performed when there are concerns about neural tube defects (NTDs), genetic abnormalities, chromosomal abnormalities.
• Used to collect amniotic fluid, safely; collection, handling, & processing need accurate procedure; protect cells from light.

Color & Appearance (Amniotic Fluid)

• Colorless/clear, blood-streaked, yellow, dark green, dark red-brown (due to meconium, fetal death)
• Hemolytic disease of the fetus/newborn (HDFN) can be detected from color.

Fetal Lung Maturity Testing

• Evaluating fetal lung maturity to determine if a premature delivery is safe.
• Lecithin-Sphingomyelin Ratio (L/S ratio) = quantitative measure of surfactant present in the amniotic fluid.
• Phosphatidylglycerol (PG) measurement- method use for fetal lung maturity.
• Foam Stability Index, and Lamellar Body Count (LBC)
• Other important criteria are needed for accurate fetal lung maturity tests.

Fetal Distress

• Hemolytic Disease of the Fetus & Newborn (HDFN).
• Elevated levels of bilirubin in cases of HDFN; and/or abnormal Liley graph (or Queenan) indicate abnormal condition/potential fetus distress.

This quiz covers the formation, physiology, and collection of cerebrospinal fluid (CSF). It highlights the role of CSF in nutrient supply and waste removal from nervous tissue, as well as its protective functions. Understanding the details about CSF is essential for exam success related to this unit.