Exam 4 (Body Fluids) Flashcards
What diluents can be used for WBC ONLY? Why?
Hypotonic saline, Dilute acetic acid, and Turk’s solution.
These all lyse RBCs
What diluents can be used for both WBCs and RBCs?
Cellpack (commercial isotonic diluent), Isotonic saline, and Hyaluronidase
What is the purpose of hyaluronidase in body fluid analysis?
Eliminates viscosity of specimen by depolymerizing hyaluronic acid
Prevents mucin clot formation
What is the formula for manual RBC/WBC counts?
cells/uL (mm^3) = (# cells counted)(dilution factor)/(area counted)(0.1)
What is the area for the small (R) squares for manual cell counts?
0.04 mm^2
What is the area for the large (W) squares for manual cell counts?
1 mm^2
What is the preferred technique for slide preparation?
Cytocentrifugation
What are the benefits of cytocentrifugation?
- optimizes cell recovery
- concentrates cells in a small area on the slide
- creates a monolayer that optimizes microscopic viewing
- fast and easy to perform
Describe cytocentrifugation
Cells adhere to glass, liquid absorbed by filter paper, cell button is formed
List the 3 meninges
Dura mater, Arachnoid, Pia mater
Where does CSF flow?
In the subarachnoid space which is located between the arachnoid and the pia mater
What is the function of CSF?
protects and supports the brain and spinal cord, provides a means of transport for nutrients and waste
How does CSF enter the bloodstream?
via arachnoid granulations
What is the total volume of CSF in neonates? adults?
Neonates: 10-60 mL
Adults: 85-150 mL
What is the blood brain barrier? Function?
The region between the blood and CSF
- Reduces the passage of substances from the blood plasma into the CSF
What accounts for the concentration differences of electrolytes, proteins, and other solutes?
Blood Brain Barrier
What is the procedure for collecting spinal fluid?
Lumbar puncture: needle goes into lumbar interspace and a pop can be heard, physician takes the opening pressure and closing pressure of CSF
How many mL of CSF can be removed safely if the pressure is in the normal range (50-180mmHg)?
up to 20 mL
List the order of sterile tubes that CSF is collected in
chemical and immunological testing (1), microbial testing (2), hematology and cytologic studies (3)
What happens with testing if only a small amount of CSF can be collected?
One tube is collected and microbiology always receives the specimen first so it can be done using sterile technique
T/F: CSF specimens are considered STAT.
True
Normal CSF appearance
clear, colorless, viscosity similar to water
What is pleocytosis?
Increased number of cells in CSF that causes a cloudy appearance
Why might there be a clot formation in CSF specimen?
Most often caused by a traumatic puncture (hit vessel during collection) but can also be due to increased FBG in CSF due to compromised BBB
What is xanthochromia?
A yellow discoloration or a spectrum of CSF discolorations
How can you tell the difference between a traumatic tap vs a hemorrhage?
Traumatic taps have no xanthochromia, and no hemosiderin while hemorrhages have hemosiderin and xanthochromia.
Traumatic taps there will be a decrease in amount of blood from first to last collection tube while hemorrhages will have the same amount of blood in all collection tubes.
There will be streaking of blood in CSF during collection with a traumatic tap, but with a hemorrhage, there will be evenly dispersed blood during collection.
What WBCs normally predominate the CSF?
Lymphocytes and monocytes
What does a high neutrophil count in CSF indicate?
Bacterial meningitis
What does increased lymphocytes in the CSF indicate?
later stages of viral, tuberculosis, fungal, and syphilitic meningitis
What does eosinophilia in the CSF indicate?
parasitic and fungal infections or allergic reactions
Are plasma cells normally present in CSF?
No; presence should always be noted
Are macrophage normally present in CSF? Why?
No; they are frequently found after hemorrhage, though.
Siderophage
Macrophage containing hemosiderin
How do proteins cross the blood brain barrier?
Pinocytosis
Which 4 protein bands are present in a normal CSF pattern? Which one helps us identify a body fluid specifically as CSF because it is not found in other specimens?
- Transthyretin (TTR)
- Albumin
- Transferrin
- Tau transferrin <—- helps us identify CSF
What is the purpose of electrophoresis of CSF?
detection of oligoclonal bands in the gamma region
What is the importance of detecting oligoclonal bands in CSF?
If there are oligoclonal bands in CSF but NOT in serum, it is highly indicative of multiple sclerosis
If there are oligoclonal bands in both CSF AND SERUM, it indicates lymphoproliferative disorder (CLL leukemia)
What will oligoclonal bands look like on an electrophoresis pattern?
Many abnormal peaks seen in the gamma region; normally should not be anything there
What is the normal range for CSF glucose? What are increased levels associated with? Decreased?
50-80 mg/dL
Increased = hyperglycemia and traumatic punctures (not significant)
Decreased = Meningitis, tumor in meninges, hypoglycemic states
What is the normal CSF IgG index? What is increased levels associated with? Decreased?
0.30-0.70
Increased levels = multiple sclerosis
Decreased levels = compromised BBB
What is the normal CSF/Serum Albumin index? What are abnormal results associated with?
Normal is <9. Increased values are associated with impairments of the blood brain barrier (>100 assumes complete breakdown of barrier)
Over 50% of meningitis cases have a decreased _________ level.
CSF glucose
What is normal CSF lactate range? What are increased lactate levels associated with?
10-22 mg/dL.
Increased lactate levels can indicate tissue hypoxia or meningitis
What do the lactate levels look like in viral meningitis vs other forms of meningitis?
Lactate <30 = viral meningitis
Lactate >35 = other causes of meningitis (bacterial)
Increased CSF lactate levels are closely associated with _______ _______ levels.
low glucose
Primary amebic meningoencephalitis
rare/deadly disease caused by amoeba Naegleria fowleri
3 organisms that cause meningitis
Haemophilus influenzae
Neisseria meningitidis
Streptococcus pneumoniae
What is the normal CSF total protein? What can increased/decreased results be caused by?
15-45 mg/dL or 150-450 mg/L
Increased: traumatic taps, meningitis, hemorrhage
Decreased: loss of fluid, increased intracranial pressure, or invasive procedures
What is the normal CSF WBC count?
0-5 WBCs/uL in adults and higher in children
What is the function of the Sertoli cells?
regulate sperm production
What is the function of the Interstitial cells of Leydig?
responsible for production and secretion of testosterone
What is the function of the testes?
Exocrine function: secretion of sperm
Endocrine function: secretion of testosterone
What is the function of seminal fluid (semen)?
Body fluid used to transport sperm
List the path of semen in the reproductive tract starting with the testes:
Testes (Sertoli cells) –> Epididymis –> Vas deferens –> Ejaculatory ducts –> Prostate gland –> Urethra
Seminal vesicle fluid vs Prostatic fluid?
Seminal vesicle fluid: accounts for 70% of ejaculate and is high in flavin and contains fructose
Prostatic fluid: accounts for 25% of ejaculate and contains proteins, enzymes, citric acid, and zinc
What enzyme does semen have a high concentration of?
Acid phosphatase
What are the rules for sperm collection? (time, temp, etc.)
Must be received in the lab within 1 hour of collection and maintained at 20-40 degrees celsius (room temp or body temp)
Briefly describe a sperm motility test.
What is normal sperm motility results?
Sperm motility graded 0-4 under a microscope, with 0 being immotile and 4 being motile with strong forward progression. Normal sperm motility results are 50% or more of the sperm showing moderate to strong forward progression (3 or 4)
Sperm count vs Sperm concentration (normal value)
Sperm concentration is the number of sperm per mL (normal is 20-250 million/mL)
Sperm count is the total number of sperm present in the entire ejaculate
How to calculate sperm count
(Sperm concentration)x(volume of ejaculate)
Describe sperm morphology test
Sperm head, midpiece, and tail are measured and/or looked at and sperm as a whole is identified as normal or abnormal
Describe a sperm vitality test. Which sperm take up the stain vs do not?
Allows for the differentiation of live and dead sperm.
Dead sperm will take up the stain, live sperm will not
How many sperm are alive in normal semen?
50% or more
What is the normal pH of semen? What does an increased vs decreased seminal fluid pH mean?
7.2-7.8.
Decreased pH indicates abnormal epididymis, vas deferens, or seminal vesicles
Increased pH indicates infection of reproductive tract
What is the major anion in semen?
Citric acid
Why might acid phosphatase be a test performed on semen?
Acid phosphatase has a uniquely high concentration in semen and is often used to determine whether semen is present in specimens after alleged sexual assault, such as vaginal fluids or stained clothing
What is the most commonly performed fecal test?
Presence for occult blood
What does the presence of occult blood indicate?
Earliest and most frequent initial symptom of colorectal cancer
Steatorrhea
Increased fecal lipids >7g/day
Major function of the small intestine
Digestion and absorption of foodstuffs
Major function of the large intestine
Absorption of water, sodium, and chloride
Diarrhea
increase in volume, liquidity, and frequency of bowel movements
Scybala
small, hard, spherical masses of feces
Secretory diarrhea
Due to increased solute secretions (could be from infestation with enterotoxin-producing organisms or damage to mucosa caused by drugs)
Osmotic diarrhea
Due to increased quantities of osmotically active solutes remaining in the intestinal lumen (malabsorption and maldigestion)
Intestinal hypermotility
Due to an increase in intestinal motility
Maldigestion vs Malabsorption
Maldigestion is inability to convert food into absorbable materials
Malabsorption is normal digestion but unable to absorb processed food
Acute diarrhea vs Chronic diarrhea
Acute: sudden onset usually due to toxin ingestion or pathogen infection; resolves in 1-2 weeks
Chronic: diarrhea lasting for longer than 4 weeks
Chronic bloody diarrhea vs Chronic watery diarrhea
Bloody: inflammatory bowel disease like ulcerative colitis or Crohn’s disease
Watery: celiac disease, tropical sprue, microscopic colitis
What is indicated if diarrhea ceases upon fasting? What if it persists despite fasting?
Ceases upon fasting –> malabsorption or maldigestion (osmotic diarrhea)
Persists despite fasting –> secretory diarrhea
What might a steatorrheal specimen look like?
pale, greasy, bulky, spongy, pasty (…..I cant believe im making a flash card for this….)
What test could be performed to differentiate steatorrhea from diarrhea?
Fecal Fat determination
What gives stool its color?
Normal brown color results from bile pigments and urobilins give feces orange-brown color
What is acholic stool?
Pale or clay-colored stools due to inhibited bile secretion into small intestine
Noninflammatory diarrhea vs inflammatory diarrhea
Inflammatory diarrhea has WBCs in it; non-inflammatory diarrhea does not
Describe Fecal WBC test
Used to determine if WBCs present in feces (inflammatory diarrhea).
Detects lactoferrin in feces; lactoferrin is present in activated neutrophils, so increased lactoferrin = increased neutrophils = intestinal inflammation
Creatorrhea
Increased numbers of fecal meat fibers which correlates with impaired digestion and the rapid transit of intestinal contents
Describe qualitative fecal fat test
2 slides made:
Slide 1 is a wet prep observed for the presence of neutral fats (triglycerides) that will stain red
Slide 2 is an aliquot of the fecal suspension acidified with acetic acid and heated to provide an estimation of the total fecal fat content (neutral fats + fatty acids + fatty acid salts)
Describe what the results mean during qualitative fecal fat test
Normal fecal neutral fat (1st slide), but increased total fat (2nd slide) = malabsorption
Increased amount of neutral fat (1st slide) = maldigestion
What color will stool blood be if bleeding in upper GI tract? Lower?
Upper GI tract bleed = dark/mahogany red colored stool (BAD)
Lower GI tract bleed = bright red blood coating surface of stool (OK)
Melena
dark or black stools resulting from presence of large amounts of fecal blood (degradation of hemoglobin)
What is gFOBT? What is the principle behind it? Positive result?
Guaic-Based Fecal occult blood test - based on the pseudoperoxidase activity of the heme moiety of hemoglobin. Positive result will be a blue color.
What foods can create a false positive gFOBT?
rare cooked meats, turnips, horseradish, cantaloupe, bananas, pears, drugs such as aspirin
what can cause a false negative gFOBT?
antacids, vitamin C
What is an iFOBT?
immunochemical based test for fecal occult blood (Hemosure) - more specific than gFOBT especially for lower GI tract bleed and does not require any food restrictions
What is the Porphyrin-Based Fecal Occult blood test?
HemoQuant test - chemical conversion of heme to intensely fluorescent porphyrins (increased porphyrins found with upper GI bleeds)
What is the Apt test? What do results mean?
Allows for blood found in stool/vomit/gastric aspirate to be differentiated whether it was from the neonate or from maternal blood ingested during delivery
Yellow brown color = maternal hemoglobin
Pink color remains (no color change) = fetal hemoglobin
Quantitative fecal fat test
Patient collects feces excreted for 2-3 days and specimen is weighed and homogenized and a portion is removed for chemical analysis of lipid content
Normal fecal fat excretion
2-7 g/day
Normal percent fat retention? What does this value mean?
95%; It means that a person is retaining 95% fat and excreting 5% fat which is normal.
What is the oral tolerance test used for? What do results mean?
Used to diagnose an intestinal enzyme deficiency.
Person ingests disaccharide and blood glucose is measured.
>30 mg/dL blood glucose = adequate enzyme
<20 mg/dL blood glucose = deficiency of enzyme
