Maribel Castañeda Hernandez
BIO 435.003
Professor Connaughton
Lab 9 Renal Physiology
Abstract
The kidneys, which are the main organs of the urinary system, function in filtering blood
to produce urine, and function in excreting waste products through the urine. Specifically, water
and other waste substances pass through the nephrons of the kidney to form the urine which is
later excreted through the urethra. Urinalysis consists of physical, chemical, and microscopic
tests of the urine. Urinalysis tests are used to detect organic and inorganic substances in the urine
such as glucose and urea. The characteristics of normal urine are shown in Table 1 under subject
B. Normal urine is clear, pale yellow in color, and is made up various constituents such as water,
sodium, sulfates, and phosphates. Urinalysis is useful to detect the presence of normal
components of urine as well as the abnormal components of urine such as glucose, albumin, red
blood cells, and ketones.
The purpose of this lab was to identify the characteristics of normal urine; to determine
organic and inorganic components in urine using different chemical tests; and to determine
different urinary conditions using the results of the chemical tests. In experiment 1, we simulated
urine formation and observed salt concentration of color changes in the solution. In experiment
2, physical parameters such as color, transparency, odor, pH, and specific gravity were recorded
for each subject’s urine sample. Urine samples from subjects A-C had were yellow in color and
had a minor smell. Each sample corresponded to a subject (e.g. Sample A from subject A)The
control sample came from subject B. Urine sample from subject D was dark yellow in color, had
a strong smell, and had a lower pH (pH=4) than the control sample (pH=8). All urine samples
were clear. Sample B has a normal specific gravity. Samples A and C had lower specific
gravities (1.000) than the normal sample (=1.010). Sample D had an abnormally high specific
gravity (1.030). In experiment 3, we conducted general tests to determine inorganic components
in each urine sample such as sulfates, phosphates, and chlorides. Subjects A and B has no
phosphates, sulfates, and chlorides. Sample C was positive for the presence of sulfates and
chlorides because precipitates for each were formed in the urine. Subject D was positive for
phosphates. In experiment 4, we conducted more tests to determine the presence of organic
constituents such as urea, glucose, proteins, mucin and ketones in the urine samples. Subject A
was positive for urea and glucose. Subject B had no trace of organic components. Subject C had
a small trace of proteins and Subject D was positive for protein with a concentration of 0.3.
Using the results of each urinalysis, we determined diagnosis for each patient. Subject A was
positive for glucose in the urine, Subject C was positive for PO4-2, and Subject D was positive for
albumin.
Urinalysis can reveal diseases that have might have gone unnoticed because of the lack of
significant symptoms or indicators of a disease. Examples of diseases that can be diagnosed
include diabetes and UTIs. With these results, patients would receive the appropriate treatment(s)
for a disease(s).
Table 1: Urinalysis for different components of urine in Patients A, B, C, & D
CHARACTERISTIC Subject A
Color
pH
Transparency
Odor
Specific gravity
Sulfates
Yellow
5
Clear
Minor smell
1.000
None
Subject B
(control)
Yellow
6
Clear
Minor smell
1.010
None
Phosphates
None
None
Chlorides
None
None
Urea
Glucose
Yes
Benedict’s
solution=
glucose present
b/c of color
change from
blue to brown
N/A
Benedict’s
solution= small
amount of
glucose present
b/c of color
change from
blue to green
Clinitest= 1%
glucose
Proteins
None
Mucin
Ketones
DIAGNOSIS
None
None
Glucosepositive
Clinitest = no
glucose
None
None
None
Control
Subject C
Subject D
Yellow
8
Clear
Minor smell
1.030
Precipitate
formed
therefore
sulfates present
None
Dark yellow
4
Clear
Strong smell
1.000
None
Precipitate
formed
therefore
chlorides
present
N/A
Benedict’s
solution= small
amount of
glucose present
b/c of color
change from
blue to green
Clinitest= no
glucose
Small trace of
proteins
detected
None
None
PO4-2
Precipitate
formed therefore
phosphates
present
None
N/A
Benedict’s
solution detected
almost no
glucose because
no change in
color
Clinitest= no
glucose
0.3
None
None
Protein/Albumin
Table 1 shows the results of each urine test for Subjects A-D. Subject B was the control. Based on
the results, Subject A was diagnosed positive with glucose in urine, Subject C was positive for PO4-2 in
the urine, and Subject D was positive for albumin in the urine. However, we were unable to determine the
presence of urea in Subject B-D due to the lack of nitric acid.