Volume 3 Flashcards
1
Q
The common measurements used in microscopy are
A
micrometer and nanometer.
2
Q
Which statement best describes simple and compound microscopes?
A
Simple microscopes contain a single lens; compound microscopes contain a group of diverse lenses.
3
Q
Which term is described as “light whose rays have been bent out of their original course by passing through a transparent membrane”?
A
Refracted.
4
Q
All of the following are examples of basic lens shapes except: flat. convex. concave. compound.
A
compound
5
Q
The resolving power of microscope lenses is its ability to
A
distinguish fine details and structures.
6
Q
The magnification system of a microscope includes
A
objectives and eyepieces.
7
Q
What component concentrates, directs, and focuses the path of light onto the object under examination?
A
Condenser.
8
Q
What is the total magnification of an object when the objective power is 20 X and the eyepiece power is 10 X?
A
200 X.
9
Q
Markers (grids, scales, etc.) used for measuring objects are placed on the
A
eyepiece diaphragm.
10
Q
To enhance light absorption and contrast of objects in brightfield microscopy,
A
stain the objects.
11
Q
Which step is incorrect when using an oil objective?
A
Pass a dry objective through the oil.
12
Q
Which microscopic method is useful in examining unstained microorganisms suspended in fluid?
A
Darkfield.
13
Q
The detailed examination of internal structures in living cells and microorganisms as they move and change shape can be accomplished by using
A
phase-contrast microscopy.
14
Q
Which microscopic method allows the study of fine details and ultra structures and what is its principle?
A
Electron microscopy; use of electron beams.
15
Q
Which human body requirement is critical because most of the chemical activities take place in this medium?
A
water
16
Q
All of the following are activities of metabolism except
a. nutrition.
b. synthesis.
c. cellular respiration.
d. internal temperature.
A
internal temperature.
17
Q
The automatic tendency of the human body to maintain a relative constant internal environment is known as
A
homeostasis.
18
Q
When discussing the various levels of organization of the human body, atoms of hydrogen and oxygen combining to form water best illustrates the
A
chemical level.
19
Q
A coordinated group of tissues and organs proceed to make
A
a body system.
20
Q
Which body system transports materials from one area of the body to another and helps defend the body against disease?
A
Circulatory.
21
Q
Statement that best describes the homeostasis function of the endocrine system?
A
Regulates metabolic activities and blood levels of various substances.
22
Q
The purpose of the ureters is to
A
transport urine produced in the kidneys to the bladder for storage.
23
Q
As the urinary bladder begins to fill, the muscular wall
A
becomes thinner.
24
Q
The tube-like structure that drains urine from the bladder and conveys it to the outside of the body is the
A
urethra.
25
What are the two main regions within the kidney covering, and where are they positioned?
Medulla - inner region; cortex - outermost region.
26
The basic functional unit of the kidney is the
nephron.
27
The combination of the glomerulus and Bowman’s capsule is often called a
renal corpuscle.
28
Kidney tubules are divided into three sections: the proximal and distal convoluted tubules, and the
loop of Henle.
29
The kidney receives its blood supply from the
renal artery.
30
Nephrons can generally be subdivided into two fluid circuits that are known as the
blood and the filtrate (urine) circuits
31
The two processes the kidney uses to produce urine are
filtration and reabsorption
32
As glomerular filtrate begins to move along the tubular system of the nephron, the process of reabsorption takes place in the
tubules.
33
What kidney disorder or disease is characterized by a sudden, serious decrease in kidney function that may be fatal?
Acute renal failure.
34
Which kidney disease is the most common and usually occurs after a streptococcal infection?
Acute glomerulonephritis.
35
Which disorder results from fluid-containing sacs destroying functional kidney parts and how is it treated?
Polycystic; dialysis or kidney transplant
36
Which one of the following is an inflammation of the bladder and in whom is it most frequent?
Cystitis; women.
37
When performing urinalysis testing, all of the following are correct except
informing the patient about the procedure(s).
38
The first step toward reporting accurate and reliable urinalysis results is
collecting a proper specimen.
39
Which specimen is generally the most concentrated and preferred for microscopic examination?
First-morning.
40
Which specimen is required for measuring the total amount of solutes excreted during a day?
24-hour urine.
41
Which one of the following is not a type of urine specimen?
Clean-catch.
42
To guarantee specimen integrity and suitability, inspect the specimen for all the following except
contamination with bacteria.
43
If the urine specimen for routine analysis cannot be analyzed within 2 hours,
refrigerate the sample or use chemical preservatives
44
Refrigeration of urine samples is adequate for most chemical components except
bilirubin and urobilinogen.
45
Refrigeration of urine samples can precipitate out
amorphous urates and/or phosphates that obscure microscopic examinations.
46
The best statement describing the abilities of most renal function tests is they can
reveal only whether or not dysfunction is present and a rough estimate of its severity.
47
The theoretical concept defined as the volume of plasma from which a measured amount of substance can be completely eliminated into the urine per unit of time is the
clearance.
48
Creatinine clearance is used for assessment of glomerular filtration rate because blood and urine assays for inulin and p-aminohippuric acid are
too difficult and time consuming to be practical in clinical laboratories.
49
Which one of the following is the major constituent of nonprotein nitrogen substances?
Urea.
50
Which of the following classifications of urea azotemia is caused by carcinoma of the bladder or ureters and kidney stones?
Postrenal.
51
Which of the following anticoagulants should not be used for plasma urea nitrogen procedures?
Ammonium heparin.
52
Indirect methods for urea are based on preliminary hydrolysis of urea with urease followed by some process that quantitates the
ammonium ion.
53
Why is an individual’s creatinine excretion rate relatively constant and what is its clearance an indicator of?
Dietary intake of creatinine causes only minor variations; GFR.
54
A disorder of purine metabolism which occurs when monosodium urates are deposited in and around joints, bursae, and subcutaneous tissues is known as
gout.
55
Which of the following uric acid methods is more specific and why?
Uricase method; has a single or initial step of urate oxidation catalyzed by the enzyme uricase.
56
Where does ammonia conversion to urea take place and why is it so important?
Liver; because of its central nervous system toxicity.
57
Falsely elevated ammonia results may be due to all of the following except
placing the specimen immediately on ice after venipuncture.
58
Normal amino acid metabolism starts in the
intestines.
59
Primary aminoaciduria and aminoacidemia is due to
an inherited enzyme defect.
60
What test is used for neonatal screening for PKU and what microorganism does it usually incorporate into the agar medium?
Guthrie test; Bacillus subtilis.
61
Which of the following urine volume terms is associated with a decreased urinary output of less than 500 ml in a 24-hour period?
Oliguria.
62
The chief or major pigment found in normal urine is
urochrome.
63
“Visible particulate matter is present and newspaper print is blurry if viewed through the specimen” is a description of the appearance term
cloudy.
64
Specific gravity is the
weight of a substance compared with that of an equal volume of another substance taken as the standard.
65
Which of the following physical characteristic measurements is not valuable in estimating the kidney’s concentrating ability?
Refractive index.
66
A reducing substance, most commonly found in urine, and is the most clinically significant is
glucose.
67
Although the renal threshold varies from individual to individual, at what levels is the renal threshold for glucose exceeded and what is the result?
160 to 200 mg/dl; glycosuria.
68
Which of the following glucose procedures is a more specific test for glucose and what methodology does it employ?
Glucose oxidase; enzymatic.
69
Which of the following interferents does not cause a false-negative or falsely lower result with the reagent strip?
Fructose.
70
Which of the following chemical(s) used in the reagent strip reacts with bilirubin to form azobilirubin?
Stabilized 2,4-dicholroaniline diazonium salt.
71
What reagent is combined with sodium nitroprusside to enhance color differentiation in the confirmatory test for ketone bodies?
Lactose.
72
Properly functioning kidneys are able to alter the specific gravity of urine in a range from
1.003 to 1.035.
73
Which of the following conditions may be a result of a transfusion reaction, severe burns, or poisoning with strong acids or mushrooms?
Hemoglobinuria.
74
What is the normal pH range of freshly-voided urine and what are the indicators used in the reagent strip?
4.5 to 8.0; methyl red and bromthymol blue.
75
Which one of the following conditions is probably the most significant pathological condition found in routine urinalysis?
Proteinuria.
76
Which of the following proteins is the primary protein fraction normally excreted in urine?
. Albumin.
77
Bence Jones protein may be found in all of the following except
a. multiple myeloma.
b. macroglobulinemia.
c. malignant lymphoma.
d. upper urinary tract infections.
upper urinary tract infections.
78
The reagent strip method for detecting protein in urine is based on the
protein error of indicators with tetrabromphenol blue as the indicator.
79
In the confirmatory test for urinary protein, the most commonly used precipitation procedure is the
sulfosalicylic acid method.
80
In what condition is urobilinogen completely absent in the urine?
Biliary blockage.
81
Why must a urine sample be fresh and protected from light before urobilinogen testing?
Urobilinogen is converted to urobilin upon standing
82
Which one of the following reagent strip tests are very useful in detecting asymptomatic urinary tract infections?
Nitrite and leukocyte esterase.
83
Which of the following stains are common supravital stains used for identifying most cells and casts in urinary sediment?
Sternheimer-Malbin and 0.5% Toluidine blue.
84
What epithelial cells in large numbers may indicate inflammatory conditions, catheterization, or a pathological process such as malignancy and how are they identified?
Transitional epithelial cells; which are round to oval and have a large, centrally located nucleus.
85
Which urinary elements contains lipid globules and may be seen in patients with severe renal dysfunction, heavy metal poisoning, glomerular injury, or diabetes mellitus?
Fatty cast.
86
What red blood cell forms may be seen in hypertonic or concentrated (high specific gravity) urine?
Crenated and prickly.
87
The presence of bacteria is considered important and clinically significant if found with
white blood cells and protein.
88
Yeast may be confused with fat globules and
red blood cells; however yeast are smaller in size.
89
Which of the following urinary crystals is probably the most common crystal encountered in urinary sediment and in what type of urine is it found?
. Uric acid; acid.
90
Which of the following urinary crystals appears as an “envelope”?
Calcium oxalate.
91
Which of the following urinary crystals are normally found in alkaline urine?
Triple phosphate and calcium carbonate.
92
Which of the following urinary crystals appears as a “coffin lid”?
Triple phosphate.
93
What abnormal crystal has a silky needle-shaped appearance and is associated with tissue degeneration or necrosis?
Tyrosine.
94
Which of the following crystals is usually flat, thin plates that can fuse into a rosette configuration and can be seen in the urine of patients with what type of condition?
Cystine; inherited metabolic disorder.
95
Which of the following casts is considered the prototype for all the other casts?
Hyaline.
96
Which of the following characteristics describe a finely granular cast?
Small, regular, and difficult to distinguish granules.
97
How are waxy casts characterized and with what condition are they associated?
Notched surface and blunt end; oliguria.
98
Most texts agree that the most diagnostically significant of all the formed elements found in urinary sediment is the
red blood cell cast.
99
In the United States, what parasite is most frequently encountered in urinary sediment?
Trichomonas vaginalis.
100
Why are 24-hour urine samples collected?
It is often valuable to know the total amount of an analyte excreted during a day.
101
1. A measurement equal to 10^-6.
MICROMETER
102
2. A measurement equal to 10^-9.
nanometer
103
3. Microscope composed of a single lens.
simple
104
4. Microscope composed of a group of diverse lenses.
compound
105
5. What you see when looking into a microscope.
image
106
6. Light is in this form of energy.
electromagnetic
107
7. The ratio of the speed of light in air to its velocity in another medium.
refractive index
108
8. Aberration due to wavelengths of white light being slowed at different rates.
chromatic
109
9. Aberration due to light rays passing through the periphery or near-center.
spherical
110
10. Flat, concave, convex, and combination, are descriptions of these.
lenses
111
11. The perception as separate of 2 adjacent objects or points.
resolution
112
12. The ability of the lenses to distinguish fine details.
resolving power
113
13. The index of the light-gathering power of a lens.
numerical apertures
114
14. This system contains the light source, condenser, and diaphragms.
illumination
115
15. The process of making something appear larger.
magnification
116
16. Provides the stability and rigidity for the microscope arm or frame.
base
117
17. Can be internal or external.
light source
118
18. A diaphragm that restricts the area of illumination or field of view.
field
119
19. A diaphragm that controls the amount of light passing through the object under examination.
iris
120
20. Concentrates, directs, and focuses the path light onto the object under examination.
condenser
121
21. An uncorrected and simple condenser.
abbe
122
22. A condenser that corrects for spherical aberrations.
aplantic
123
23. Horizontal platform or shelf that may be rectangular or circular.
stage
124
24. The major part of the magnification system.
objective
125
25. Secures and allows easy rotation of objectives.
nosepiece
126
26. Usually 160 mm in length and may contain a prism.
body tube
127
27. Further magnifies the real image projected by the objectives.
eyepieces
128
28. Serve to bring the objective and object under examination closer or farther apart.
focus knobs
129
An illumination system that allows detailed examination of internal structures in living objects as they change shape.
Phase-contrast.
130
Uses transmitted light to reveal structural details of an object; primary type of microscope used in the clinical laboratory.
Brightfield.
131
Uses special components to separate excitation wavelengths from emission wavelengths.
Fluorescence.
132
Examines live microorganisms and uses a condenser with an opaque disc.
Darkfield.
133
Objects appear as 2-dimensional and use salts of heavy metals as stains.
Transmission electron microscopy.
134
Produces a 3-dimensional view and used in histology for viewing dissections.
Stereoscope.
135
Object details appear darker than the illuminated field of view.
Brightfield.
136
Is used to study fine details and ultrastructures of cells, microorganisms, tissue, and other objects.
Electron microscopy.
137
Light rays are refracted by various structures within the object showing varying degrees of brightness.
Phase-contrast.
138
A method that ensures optimum contrast and resolution.
Köhler illumination.
139
Provides a striking 3-dimensional view by knocking off electrons from the object.
Scanning electron microscopy.
140
Use only the fine adjustment for focusing when using this type of objective.
Oil immersion.
141
What are the requirements for life?
Water, oxygen, food, appropriate temperature, and suitable environment.
142
What are the differences between living and nonliving things?
Living things move, support self-regulated metabolism, respond to internal and external changes, grow, and reproduce; nonliving things are not capable of these on their own.
143
What is anabolism?
The phase of metabolism in which the body uses energy to produce the chemical substances required for growth, repair, and maintenance of all body systems.
144
What is catabolism?
The breaking-down phase of metabolism; converts the energy of food into forms that can be used by the body to provide energy needed to carry on the processes of life.
145
What are the 3 interdependent activities of metabolism? Briefly describe each.
Nutrition, synthesis, and cellular respiration; nourishing the body through the breakdown of nutrients; using some of these nutrients to manufacture or synthesis new substances for the building of new body parts or as fuel for cellular respiration; providing a process of gas exchange within the cells as nutrients are slowly broken down for fuel.
146
What must an organism do to carefully regulate metabolism?
Know when nutrients are needed, when to manufacture what, and when to breakdown substances for fuel or energy; and when not to produce too much of any substance.
147
What is homeostasis?
A control mechanism for maintaining a constant, appropriate internal environment.
148
How does homeostasis work?
All body systems participate in the regulatory mechanisms of homeostasis by doing what they were designed to do; if they don’t, negative feedback is sent to activate control mechanisms (nervous or endocrine system that activate another system or systems to compensate for the disruption).
149
What are the different levels of the human body? List them in building order.
Chemical, cellular, tissue, organ, system, and organism.
150
Which is the most complex level?
Cellular.
151
Of what does a body system consist?
A coordinated group of tissues and organs.
152
What controls the regulatory functions of the body systems?
Nervous and endocrine systems.
153
Maintains adequate supplies of fuel molecules and building materials, eliminates wastes and toxins.
digestive
154
Provides movement for parts of the skeleton, pumps blood, aids in movement of internal structures.
muscular
155
Maintains oxygen content in tissue and cells, eliminates carbon dioxide and other waste.
respiratory
156
Controls body temperature through sweat glands, a barrier from harmful substances and carrier for helpful substances.
dermal
157
Filters blood, removes wastes and foreign substances; regulates ion, salt, and water concentrations of fluids; produces renin and erythropoietin.
urinary
158
Primary regulatory system, controls all other systems.
nervous
159
Provides the body’s supportive framework; protects internal organs; provides blood cell formation.
Skeletal.
160
Distribution of oxygen, nutrients, wastes, body fluids and solutes, and body heat.
circulatory
161
Passes on genetic codes for all cells.
Reproductive
162
Regulates metabolic activities and blood levels of various substances.
endocrine
163
Transports materials from one area of the body to another, defends the body against disease.
circulatory
164
Protects and covers the body, acts as a sensory receptor.
dermal
165
List examples of external stressors.
Heat, cold, noise, abnormal pressure, harmful radiation exposure, and lack of oxygen.
166
List examples of internal stressors.
Changes in blood pressure, pH, or salt concentration; and high or low blood-sugar levels.
167
Where are the kidneys located?
Under the dome of the diaphragm, behind the peritoneum (known as retroperitoneal space) in the posterior wall of the abdominal cavity, on either side of the vertebral column.
168
How many tissue layers does the kidney have and how are they designated?
3; the innermost layer is called the renal capsule, the middle layer is adipose capsule, and outermost layer is the renal fascia.
169
Where are the ureters located and what is their function?
They are located in the retroperitoneal space and run parallel with the vertebral column; transport the urine, produced in the kidney, to the urinary bladder for storage.
170
How is urine moved along the ureter?
Peristalsis.
171
Where is the bladder located and what is its function?
It is located within the pelvic cavity, behind the pubic symphysis (joint); anterior to the rectum in a male and anterior to the uterus in a female; reservoir for urine.
172
What keeps the bladder from automatically emptying?
The internal sphincter and conscious control keep the external urethral sphincter contracted.
173
What are the differences between the female and male urethra?
The female urethra is shorter than the male urethra and the male urethra is part of the reproductive system.
174
What are the two main regions within the kidney covering?
Medulla and cortex.
175
Where is the medulla located and what does it contain?
Inner region of the kidney; renal pyramids.
176
Where is the cortex located and what does it contain?
Outermost region of the kidney; renal corpuscles, proximal and distal convoluted tubules, peritubular capillaries, and medullary rays.
177
What is the basic functional unit of the kidney and about how many are there?
Nephron; about a million.
178
Of what is the renal corpuscle composed?
Bowman’s capsule and glomerulus.
179
What are the three sections of the tubule that is connected to Bowman’s capsule?
The proximal and distal convoluted tubules, and the loop of Henle.
180
What are the two fluid circuits of the nephron?
The blood circuit and the filtrate (urine) circuit.
181
The fluid in the blood that is constantly being squeezed into Bowman’s capsule.
Glomerular filtrate.
182
(2) If the input is high, the kidneys must increase output to keep from flooding the internal environment.
Body fluid homeostasis.
183
(3) Kidneys secrete an enzyme called erythropoietic factor.
Red blood cell production.
184
(4) Occurs as water and dissolved substances are forced out of the glomerulus and
into Bowman’s capsule
Filtration.
185
(5) Takes place in the tubules, includes the interaction of the tubules and peritubular
capillaries.
Reabsorption.
186
(6) Most common disease of the kidneys.
Acute glomerulo- nephritis.
187
(7) Indicates the actual expulsion or emptying of the hollow organs.
Elimination.
188
(8) When our fluid intake is low and output high, the body calls on the kidneys to further concentrate urine to help conserve fluids.
Body fluid homeostasis.
189
(9) Inflammation of the kidney pelvis and the tissue of the kidney itself.
Pyelonephritis.
190
(10) Usually grow rather slowly, but occasionally rapidly invading types are found.
Kidney tumors and cysts.
191
(11) Made of certain substances, such as uric acid and calcium salts, which precipitate out of the urine instead of remaining in solution.
Kidney stones.
192
(12) Removal of metabolic waste from the blood and excretion of the waste products from the body is the major function.
Urinary system.
193
(13) It is composed of amino acids, urea, uric acid, creatine, water, and a host of ions including sodium, potassium, chlorine, phosphate, sulfate, calcium, and bicarbonate.
Glomerular filtrate.
194
(14) Is frequently seen in patients with urinary tract blockage or obstruction.
Pyelonephritis.
| Hydronephrosis.
195
(15) The function of removing useless substances or waste products.
Excretion.
196
(16) The kidneys play an important role in regulating blood volume.
Blood pressure regulation.
197
(17) Involves the use of several different mechanisms to remove fluid, ions, and other dissolved substances from the tubules.
Reabsorption.
198
(18) Carbon dioxide and water are excreted.
Respiratory system.
199
(19) Usually occurs in children about 1 to 4 weeks after a streptococcal infection of
the throat.
Acute glomerulo- nephritis.
200
(20) Many fluid-containing sacs develop in the active tissue and gradually, by
pressure, destroy the functioning parts.
Kidney tumors and cysts.
201
(21) Cystitis is 10 times more frequent in women as in men.
Disorders involving the bladder.
202
(22) Include double portions at the kidney pelvis and constricted or abnormally narrow parts, called strictures.
Disorders of the ureters.
203
(23) Inflammation of the mucous membrane and the glands; much more common in the male than in the female and is often due to gonorrhea.
Disorders of the urethra.
204
What is the first step in specimen collection and who initiates this step?
The order or request for the laboratory to perform a procedure; physician or another qualified individual.
205
Besides the identification information, what information should be added to the urinalysis request form?
The reason for ordering the test (chief complaint, symptoms, surgery, etc.), medications patient is taking, how the specimen was obtained (mid-stream, catheter, aspiration, etc.), and the time and date of collection.
206
Before giving a patient a collection container and instructions, what should you do?
Check the patient’s ID card, ask him or her to state his or her name and SSN, or have him or her visually verify the information on the request form.
207
What criteria should the primary collection container and transport container meet?
Should be clean, leak-proof, and preferably made of a clear, disposable material that will not react with urinary constituents, have a wide base to help prevent accidental spillage, and have a lid free of interfering substances.
208
Where should the label be placed and what information should it include?
Place labels on the container, full name, SSN or hospital identification number, date and time of specimen collection, identity of the preservative, if used, and a barcode label if required.
209
If you aren’t sure about patient instructions for a procedure, where can you look for the information?
Laboratory guide and OI.
210
What characteristics should verbal or written instructions have?
Instructions must be accurate, concise, and clear.
211
At what time is a random specimen collected?
Unspecified time.
212
How do you describe a timed specimen?
The timed specimen is collected at a specified time within a 24-hour period, (e.g., at 10 am) or at a specified time in relation to another activity (i.e., 2 hours after eating a meal or immediately after prostatic massage).
213
Why are timed specimens important?
Since urinary substances are excreted in varying concentrations throughout the day, it is imperative to collect timed specimens in order to accurately quantitate certain substances.
214
What is given to a patient before collecting a time specimen and what does it include?
Before beginning a timed collection a patient should be given written instructions with regard to diet or drug ingestion to avoid interference of ingested compounds with analytical procedures.
215
Which specimen is preferred for microscopic examination and provide a description of this specimen?
The first morning, early-morning fasting, or 8-hour specimen; normally collected immediately on the patient’s arising from a night’s sleep.
216
What specimen is used to measure the total amount of solutes during a day and why?
A strictly timed 24-hour specimen is required because many solutes exhibit diurnal variations.
217
How do you describe the collection process of a 24-hour specimen?
At the beginning of the collection, the bladder is emptied and urine is discarded; at each voiding during the collection period, urine is collected in a separate container and then emptied into a larger container which is stored at 2 to 8°C until delivery to the laboratory.
218
When should a catheter specimen be collected and on whom?
For microbiologic examination in critically ill patients or in those with urinary tract obstruction and/or if contamination by vaginal contents in female patients may contaminate the specimen or alter results.
219
When should a clean-catch specimen be collected?
Microbiology studies or urine cultures and for a true concentration of white cells.
220
What does clean-catch mean?
Clean-catch just means that the area around the urethra was cleaned before the specimen was collected.
221
What characteristics must the transport container have?
The same characteristics of the collection container; a tight-fitting lid that is easily applied and removed.
222
To ensure specimen integrity and suitability, for what should you inspect?
(1) The patient information on the request slip must match the information on the container label; (2) the specimen must be <2 hours old if not preserved; (3) the specimen must be in the proper container and the lid must be tightly in place; (4) the outside of container must not be contaminated with the specimen; (5) the specimen volume must be adequate and be free of contaminating materials; and (6) the presence or absence of chemical preservative must be consistent with the procedure requested.
223
When can you discard an unacceptable specimen?
Never discard an unacceptable specimen until the appropriate care providers have been consulted and a mutually agreeable decision has been reached.
224
If there is a delay in analysis, what should you do?
Refrigerate or use chemical preservatives.
225
When is refrigeration, instead of chemical preservatives, recommended and what is the exception?
For routine urinalysis; bilirubin and urobilinogen measurements.
226
What is the drawback of chemical preservatives?
Unfortunately, there is not a good overall chemical preservative because each preservative interferes with a different urine analyte or the analytical method in some way.
227
Who or what should you review before using a urine chemical preservative?
Your laboratory’s guide and/or OI, in addition to the references laboratory’s shipping guide.
228
What are some of the problems with renal function testing?
Various enzyme and transport systems coexist within the urinary system; some are related while others are physically and physiologically quite separate; and the kidney has many functions that may or may not be affected in a given pathologic process or disease.
229
What can the laboratory basically measure for renal evaluations?
What passes into and out of the kidney.
230
What do practical renal evaluations include?
The nephron functions of glomerular filtration, the tubules’ reabsorptive capacity for water and electrolytes as manifested by their urine concentration abilities, and the kidney’s ability to excrete endogenous and exogenous compounds.
231
Most clinical laboratory information used to assess renal function is derived from what measurement?
The clearance of some substances from the kidneys.
232
On what does renal clearance depend?
The plasma concentration and excretory rate, which, in turn, involve the GFR and renal plasma flow (RPF).
233
What are the primary or reference substances used for measuring GFR and RPF respectively?
Insulin (a naturally occurring polysaccharide); p-aminohippuric acid (PAH).
234
Why is the creatinine clearance test used in most clinical laboratories?
Because the necessary blood and urine assays for inulin and PAH are too difficult and too time-consuming.
235
The creatinine clearance procedure includes what type of measurements?
Serum or plasma and urine creatinine.
236
What are the two main groups of nitrogen containing substances?
Protein nitrogen (protein substances containing nitrogen) and nonprotein nitrogen (NPN) substances.
237
What are the NPN compounds?
Urea, creatine, creatinine, uric acid, ammonia, and amino acids.
238
From what and how is urea produced?
The use of proteins (in the form of amino acids) by the body’s cells produce waste materials that contain the element nitrogen; chiefly urea—which occurs primarily in the liver through hepatic enzymes.
239
what is the result of waste product build-up?
If waste products (toxic chemicals) are allowed to build up in the blood stream, all of the body’s cells and systems are literally poisoned which leads to the death of the cell, organ, system, and the body.
240
What are the three classifications of azotemia?
Prerenal, renal, and postrenal urea azotemia.
241
What are the two laboratory procedures for urea and briefly describe each?
Indirect; based on preliminary hydrolysis of urea with urease followed by some process that quantitates the ammonium ion; and direct methods, the condensation of diacetyl with urea to form the chromogen diazine.
242
Where and how is creatine synthesized?
Creatine is synthesized in the kidneys, liver, and pancreas by two enzymatically mediated reactions.
243
Why is an individual’s creatinine excretion rate relatively constant?
Dietary (exogenous) intake of creatinine causes only minor variations in daily creatinine excretion and it parallels endogenous production.
244
Why does hemolysis cause falsely elevated creatinine results?
Because of the release of noncreatinine chromogens from the cells.
245
Creatinine methods are based on what reaction and what is used to improve the specificity of this method?
Jaffé reaction; an acid blank.
246
What are the two enzymes used in creatinine enzymatic assays?
Creatininase (creatinine iminohydrolase or deiminase) and creatinine hydrolase (creatinine amidohydrolase).
247
What is the definitive method for measuring creatinine?
Isotope-dilution mass spectrometry.
248
What is uric acid and where is it primarily produced?
The major product of the catabolism of purine nucleosides; production occurs primarily in liver and intestinal mucosa.
249
What are the major causes or hyperuricemia?
Increased uric acid synthesis, decreased renal excretion of uric acid, and miscellaneous causes.
250
What is gout and how does it occur?
Gout is aDisorder of purine metabolism or renal excretion; when monosodium urate precipitates, from supersaturated body fluids, deposit in and around joints, bursae, periarticular cartilage, bone, and subcutaneous tissue.
251
What are the forms of renal disease associated with hyperuricemia?
(1) Gouty nephropathy with urate deposition in renal parenchyma; (2) acute intratubular deposition of urate crystals; and (3) urate nephrolithiasis.
252
Why is medical treatment justified in asymptomatic hyperuricemia?
In order to prevent urate-induced renal damage.
253
Hypouricemia can be seen in what disorders?
Severe liver disease with decreased synthesis of purines, hereditary deficiency of xanthine oxidase, administration of uricosuric drugs, and a defect in renal tubular reabsorption of uric acid (Fanconi’s syndrome).
254
What are the two groups of uric acid testing methods?
Phosphotungstic acid methods (spectrometric) and uricase methods (enzymatic).
255
What is the definitive method for measuring uric acid?
Gas chromatography/mass spectrometry (GC/MS).
256
What is the major source of circulating ammonia and what is it a product of?
Gastrointestinal tract; amino acid metabolism.
257
What effect does excess ammonia have and is a major cause of hyperammonemia in infants?
Toxic effects on the central nervous system; inherited enzyme deficiencies of the urea cycle?
258
Why is plasma the specimen of choice for ammonia procedures and which anticoagulants should be used?
Because ammonia procedures must be performed immediately after the venipuncture; EDTA and heparin (without ammonia salts).
259
Why is the specimen immediately placed on ice?
To prevent in vitro metabolism of nitrogenous compounds and the degradation of glutamine.
260
What can cause falsely elevated ammonia results?
Smoking, laboratory atmosphere contamination, poor venipuncture, and metabolism of nitrogenous constituents.
261
What are amino acids and why are they important?
Organic compounds containing an amino (–NH2) and a carboxyl (–COOH) group; they are the building blocks for proteins.
262
What is the cause of primary aminoaciduria and aminoacidemia?
Primary disease is due to an inherited enzyme defect, also called an inborn error of metabolism.
263
What is phenylketonuria (PKU)?
Phenylketonuria is the most severe manifestation of hyperphenylalaninemia due to phenylalanine 4- monooxygenase deficiency, with accumulation and excretion of phenylalanine, phenylpyruvic acid, and related compounds and inherited as an autosomal recessive trait.
264
How is PKU characterized?
It is characterized by severe mental retardation, tumors, seizures, hypopigmentation of hair and skin, eczema, and a mousy odor.
265
How are these characterizations prevented?
By early restriction of dietary phenylalanine.
266
What is the most widely used test for PKU screening and describe it?
Guthrie test; bacterial spores (Bacillus subtilis) and a phenylalanine competitive growth inhibitor are incorporated into an agar medium, blood or urine soaked filter paper is laid on the agar surface, and the plate is incubated and observed for bacterial growth.
267
How is a positive Guthrie test confirmed?
Thin-layer chromatography, ion-exchange or high-performance liquid chromatography, and gas chromatography/mass spectrometry.
268
Difficult to define or describe, but can indicate certain disease processes.
Odor.
269
Relates to the hydrogen ion (H+) concentration or activity of a solution compared to a given standard solution.
pH.
270
The ratio of density (weight per unit volume) of a solution compared to the density (weight per unit volume) of an equal volume of water at a constant temperature.
Specific gravity.
271
Derived from the food we have eaten or are the waste products of metabolism.
Normal constituents.
272
Some shade of yellow: almost colorless, yellow-green, straw, pale yellow, bright yellow, yellow-orange, light amber, or dark amber.
Color.
273
Defined as the particles dissolved in a solution.
Osmolality.
274
Results from the presence of urochrome, uroerythrin, and urobilin.
Color.
275
Total lack of urine output.
Anuria.
276
The ratio of the velocity of light in air to the velocity of light in solution.
Refractive index.
277
Valuable test when estimating the kidney’s concentrating ability.
Osmolality.
278
Occurs particularly in diabetes mellitus and diabetes insipidus.
Polyuria.
279
Total urine volume is more than 2 liters in a 24-hour period.
Polyuria.
280
Described as clear, hazy, cloudy, and turbid.
Appearance.
281
Urinary output of less than 500 ml in a 24-hour period.
Oliguria.
282
Urea, sodium chloride, phosphoric acid, sulfuric acid, uric acid, hippuric acid, creatinine, ammonium, potassium, calcium, oxalate, phosphate, amines, amino acids, proteins, enzymes, purines, leukomaines, urobilin, sugars, cholesterol, hormones, fatty acids, vitamins, and metals.
Normal constituents.
283
What is on the reaction or reagent pads of reagent strips?
The reagents required for the detection, reaction, and estimation of the analyte; and usually a buffer and other nonreactive components or chemicals.
284
Where can you find the incubation time sequence and corresponding color chart for the reagent strips?
Manufacturer’s instructions in the product insert or on the reagent bottle.
285
What can the color change on the reagent pad represent?
A numerical value, positive or negative result, or a plus (+) grading scale (i.e., 1+, 2+, 3+, or 4+).
286
What are the sugars that can be found in urine with the most common listed first?
Glucose (most common), lactose, fructose, galactose, and pentose (arabinose and xylose).
287
What determines how high blood glucose levels will rise before glycosuria occurs?
Renal threshold of each individual.
288
How do you define renal threshold?
Renal threshold is the term used for any glucose level that exceeds the concentration that cannot be reabsorbed by the renal tubules and is excreted in the urine.
289
Screening urine specimens for glucose is the best method for detecting what disorder?
Diabetes mellitus.
290
What other pathological conditions can cause glycosuria?
Kidney disease, pancreatic disease, endocrine disorders, liver disease, and damage to the central nervous system.
291
What are some of the normal conditions that can cause glycosuria?
Stress situations and pregnancy, after exercise, and/or associated with anesthesia.
292
What is a brief definition of reducing substances and name a few?
Substances can reduce a heavy metal from a higher to a lower oxidation state, for example copper (II) to copper (I); glucose, creatine, uric acid, homogentisic acid, ascorbic acid, chloroform, formaldehyde, lactose, fructose, galactose, and pentose (arabinose and xylose).
293
What is a more specific test than the Benedict’ reaction for glucose and why was it required?
Glucose oxidase method, an enzymatic assay; false-positive glucose results due the presence of other reducing substances.
294
What can cause false-negative or decreased results with this test?
Large amounts of ascorbic acid from vitamin C or drugs (tetracyclines), presence of ketones, and refrigerated specimens.
295
Why is it important to detect bilirubin in the urine?
It is an important early indicator of liver dysfunction and/or biliary obstruction.
296
What reagent is on the reagent strip and how is bilirubin detected?
Stabilized 2,4-dichloroaniline diazonium salt; 2,4-dichloroaniline diazonium salt that reacts with bilirubin in a strongly acid medium to form azobilirubin.
297
Why must the urine specimen be absolutely fresh for bilirubin testing?
Because bilirubin rapidly breaks down when exposed to light and due to the oxidation of bilirubin to biliverdin.
298
What can cause false-positive and false-negative results, respectively?
Highly pigmented urine; large amounts of ascorbic acid or nitrites.
299
When are ketone bodies found in the blood and urine?
When fat is used as a major source of energy in place of carbohydrates.
300
What are the three ketone bodies found in urine?
Acetoacetic acid, β-hydroxybutyric acid, and acetone.
301
What effect do high ketone levels have on the human body?
Depletes the body of its anions and thus produces acidosis.
302
How does the reagent strip detect ketone bodies and which ketone body does it detect?
Sodium nitroprusside reacts with acetoacetic acid to form a purple color; only acetoacetic acid.
303
A urine specimen specific gravity above 1.025 is a characteristic of which clinical conditions?
Congestive heart failure (CHF), severe liver damage, dehydration, or severe water loss from vomiting or diarrhea.
304
What is the principle of the specific gravity indirect test method?
A change in ionic concentration of a solution initiates a change in the dissociation constant (pK) of pretreated polyelectrolytes (polymethylvinyl) and this ionic change is detected by bromthymol blue (pH indicator).
305
What is the confirmatory test for specific gravity?
Refractometer or urinometer.
306
Hematuria indicates what diseases or disorders?
Bladder and kidney tumors; trauma to the kidneys; glomerulonephritis; pyelonephritis; renal calculi (kidney stones); and bleeding disorders.
307
Hemoglobinuria can be associated with what conditions?
Trauma; intravascular hemolysis due to transfusion reactions, hemolytic anemias, or paroxysmal nocturnal hemoglobinuria; severe infections such as malaria, etc.; severe burns; poisoning with strong acids or mushrooms; or trauma from neoplastic diseases.
308
In what conditions is myoglobinuria seen?
Traumatic muscle injury acquired from automobile accidents, beatings, or crush injuries; excessive unaccustomed exercise; exposure to toxic drugs or substances; and in rare hereditary disorders.
309
How are hematuria, hemoglobinuria, and myoglobinuria distinguished?
A combination of gross observations and chemical procedures.
310
What reagents are in the reagent pad for hemoglobin and what is the basis for detection?
The peroxidase-like activity of hemoglobin, which catalyzes the reaction of diisopropylbenzene dihydroperoxide and 3,3’,5,5’-tetramethylbenzidine to form a color change.
311
What is the normal pH range of urine and what is the mean pH?
4.5 to 8.0 with a mean between 5.0 and 6.0.
312
4.5 to 8.0 with a mean between 5.0 and 6.0.
Methyl red and bromthymol blue indicators.
313
What is probably the most significant pathological condition found in routine urinalysis and what causes this condition?
Proteinuria; glomerular damage, tubular damage, or overflow from excessive production of low-molecular weight proteins.
314
What protein replaces albumin as the predominant protein found in the urine of patients with multiple myeloma?
Bence Jones protein.
315
What conditions can cause normal or healthy persons to excrete abnormal quantities of protein in the urine?
Strenuous physical exercise, pregnancy, exposure to extreme cold, and psychological stress.
316
What is the principle of the reagent strip for protein and what is the basis of detection?
Colorimetric methodology based on the concept of the protein error of indicators.
317
Depending on the patient population, what may be required for protein testing?
Both reagent strip and precipitation methods.
318
What is the most common precipitation procedure used for protein testing and how is the actual type of protein present identified?
Sulfosalicylic acid method; electrophoresis, immunoelectrophoresis, immunodiffusion, or ultracentrifugation techniques.
319
Under what conditions is urobilinogen completely absent from urine and feces?
Biliary blockage.
320
How is urobilinogen and other bile pigments detected?
Ehrlich reaction; in which urobilinogen reacts with para-dimethylaminobenzaldehyde in a strongly acid medium to form a pink-red color.
321
Which test is a rapid screening method to detect the presence of bacteria in urine?
Nitrite.
322
What does the nitrite test depend upon?
Upon the conversion of dietary nitrate to nitrite by the action of bacteria in the urine.
323
What can the leukocyte esterase test, in conjunction with the nitrite test, successfully detect?
Asymptomatic UTIs.
324
The reagent strip for the leukocyte esterase tests is based on what test methodology?
The principle that leukocyte esterase catalyzes the hydrolysis of the derivatized pyrrole amino acid ester to liberate 3-hydroxy-5-phenyl pyrrole and then this pyrrole reacts with a diazonium salt to produce a purple end product.
325
Under what circumstances is a microscopic examination usually performed?
When requested by the physician; when determined by laboratory protocol (e.g., immunosuppressed, urology-nephrology, diabetic, or pregnant patients); and when any abnormal physicochemical or reagent strip result is obtained.
326
What is the specimen of choice for urine microscopic examinations and why?
The first-morning specimen because it is the most concentrated.
327
What items or areas of urine specimen processing should be standardized?
Volume of urine centrifuged, time and speed of centrifugation, concentration and volume of sediment examined, and reporting results.
328
What are the stains used for identifying elements of urinary sediment?
Sternheimer-Malbin, 0.5% Toluidine blue, Oil red O, Sudan III, Gram stain, Papanicolaou Hansel, Wright- Giemsa, Papanicolaou, and Prussian blue.
329
Largest of the epithelial cells found in urine.
squamous
330
Line the renal pelvis and calyces, ureter, and urinary bladder.
transitional
331
Line the tubules within the nephron.
renal
332
. Renal tubular epithelial cells filled with absorbed globules of lipid.
oval fat bodies
333
Can be free-floating.
lipid globules
334
Casts that contain free fat or oval fat bodies.
fatty casts
335
Increased numbers ordinarily indicates inflammatory conditions.
white blood cells
336
Appear as smooth biconcave disks.
red blood cells
337
. Found in hypotonic or dilute urine.
ghost cells
338
Found in hypertonic or concentrated urine.
crenated cells
339
Absence of motility due to urine toxicity.
spermatozoa
340
Can be either a bacillary or coccal form.
bacteria
341
May be confused with fat globules or red blood cells.
yeast
342
Common element found more frequently in women than in men.
mucus
343
Appear to be twinkling in fresh urine.
glitter cells
344
Acronym for polymorphonuclear neutrophils.
pmns
345
Ghost cells result in this type of urine.
hypotonic
346
Crenated cells are found in this type of urine.
hypertonic
347
Immunological studies show that this is part of the mucus.
Tamm horsfall protein
348
Sometimes confused with red blood cells, but vary greatly in size.
bubbles
349
The second most frequently seen crystal.
Calcium oxalate.
350
Present in alkaline urine; vary in size, and usually have a prismatic form that is described as a coffin lid.
Triple phosphate.
351
Spheroids with a dense central area or nidus surrounded by concentric bands; spokes radiate from the nidus.
Leucine.
352
Large, flat, transparent rectangular plates with irregular sides that often show a missing corner or staircase pattern.
Cholesterol.
353
May be in the shape of rods, cubes, rosettes, six-sided plates, rhombi, stars, spears, needles, barrels, and whetstone.
Uric acid.
354
Typically translucent, colorless, cigar-shaped, and somewhat difficult to see because of their low refractive index.
Hyaline.
355
Granules vary in size and shape; seen in renal diseases where extensive cellular damage and death have occurred.
Coarsely granular.
356
Presence of large numbers in urinary sediment indicates severe, chronic renal disease.
Waxy.
357
The most diagnostically significant of all the formed elements found in urinary sediment.
Red blood cell.
358
Fine, brownish tan granules that usually precipitate in neutral or acid urine that has been refrigerated.
Amorphous urates.
359
Two basic shapes: octahedral and dumbbell; octahedral shape appears as an envelope.
Calcium oxalate.
360
Formation due to alterations in urine flow, pH, ionic strength, concentration, and salinity of the glomerular filtrate.
Casts.
361
Flat, thin, six-sided (hexagonal) plates, that are clear and colorless; seen in patients with inherited metabolic disorders.
Cystine.
362
Classified as acellular or cellular.
. Casts.
363
Should only be considered pathogenic when found in fresh, warm urine.
Uric acid.
364
They often appear as fan-shaped bundles or sheaves of wheat.
Sulfadiazine.
365
Described as crab-like, thorn-apple, and scorpion-like.
Ammonium urate.
366
Found in the urine of patients with renal diseases, the nephrotic syndrome, and lymphatic obstruction.
Cholesterol.
367
Slightly brown granules that tend to aggregate into groups or clumps, especially after refrigeration; present in alkaline urine.
Amorphous phosphates.
368
Characterized by blunt, broken-off or cut-off ends (not rounded), notched or indented sides that are parallel.
Waxy.
369
Have a high potential for forming renal calculi.
Calcium oxalate.
370
The only elements left are the membranes of the red blood cells and the brownish-red pigment in the cast.
Hemoglobin.
371
Have a fine, delicate, silky needle-shaped appearance; associated with tissue degeneration or necrosis (liver disease).
Tryosine.
372
Granules are small, regular, and difficult to distinguish from one another; seen in patients with intrinsic renal disease.
Finely granular.
373
The most common crystals encountered in urinary sediment.
Uric acid.
374
Have a high refractive index, possess anisotropic properties, and are usually much longer than urinary casts.
Fiber.
375
Casts are associated with kidney infections and may be seen in bacteriuria, if the inflammation is initiated by bacteria.
White blood cell.
376
. Associated with fulminate hepatitis, advanced cirrhosis, congenital metabolic conditions, and hepatocellular poisons.
Leucine.
377
Regarded as the prototype for all the other casts; occasionally one end may be drawn out into a tail or point.
Hyaline.
378
Confused with bacteria because of their small size and dumbbell size; produce bubbling when acid is added.
Calcium carbonate.
379
Cells are often sloughed off the tubule into the urinary stream and then attached to the cast matrix.
Epithelial.
380
Eggs or ova are oval in shape with one side slightly flattened; contaminated by fecal material.
Enterobius vermicularis.
381
Ordinarily a contaminant from the vagina.
Trichomonas vaginalis.
382
Commonly found in urine specimens collected by catheterization and use of surgical gloves.
Starch granules.
383
They are present in a wide variety of renal diseases, but are most prominent in nephrotic syndromes.
Epithelial.
384
Seen mostly in incontinent babies and elderly persons. It is generally identified by its brown coloration, assortment of bizarre shapes.
Fecal contamination.
385
What is included in 24-hour urine processing?
Measuring the total volume of urinary output and aliquoting the specimen into proper containers for analysis.
386
Why are 24-hour urine specimens collected?
Clinically it is often valuable to know the total amount of an analyte, excreted in the urine during a 24-hour period and in order to obtain a quantitative analyte value.
387
What calculi are the most prevalent and when is the onset?
Calcium oxalate; between 30 and 40 years of age.
388
What is the passage of calculi characterized by?
Renal colic; severe pain in the back, radiating to the groin.
389
What are some of the disorders caused by renal calculi?
Hematuria with extreme pain is common, obstruction of the kidney pelvis or ureter can cause hydronephrosis, and infection.
390
How do semiautomated instruments read the reagent strip?
By a reflectance spectrophotometer that analyzes the color intensity of the light reflected from the reagent area.
391
In automated instrument methodology how are specific gravity and urine chemistries measured?
Mass gravity meter; urine chemistries are measured by a standard reflectance spectrophotometer.
392
What does urinalysis quality control include?
Running high and low matrix controls, equipment and instrument maintenance, and method validation.
