NAME _____________________________________________
3.4: Review Sheet
3.4.a. What are the functions of the urinary system?
In the spaces below fill in the 5 functions of the urinary system. Refer to 3.4.3 if you need help:
a. _________________________________________________________________________
b. _________________________________________________________________________
c. _________________________________________________________________________
d. _________________________________________________________________________
e. _________________________________________________________________________
3.4.b.
What are the major organs of the urinary system?
Label the diagram to the left. Record the
function of the organs below:




3.4.c.
What is the general structure of the kidney and how does this structure relate to kidney function?
Label the internal anatomy of the kidney in the
diagram to the right. Ignore #7 and #4,5 are
the same!
 The functional unit of the kidney is the
_______________________

The functional unit has parts in both the
________________________ and
_________________________ layers.

The functional unit ends at the
_______________ where urine is
collected and transported out of the
kidney.
3.4.d.
How does the kidney form urine?
Your body takes nutrients from food and uses them to
maintain all bodily functions including energy and selfrepair. After your body has taken what it needs from
the food, waste products are left behind in the blood
and in the bowel. The urinary system works with the
lungs, skin, and intestines-all of which also excrete
wastes-to keep the chemicals and water in your body
balanced. Adults eliminate about a quart and a half of
urine each day. The amount depends on many
factors, especially the amounts of fluid and food a
person consumes and how much fluid is lost through
sweat and breathing. Certain types of medications can
also affect the amount of urine eliminated.
The urinary system removes a type of waste called
urea from your blood. Urea is produced when foods
containing protein, such as meat, poultry, and certain
vegetables, are broken down in the body. Urea is
carried in the bloodstream to the kidneys.
3.4.e. What is the relationship between blood and urine?
The urine is formed from wastes and extra water filtered or secreted out of the blood.
3.4.f.
What is the function of the nephron?




Label the diagram of the nephron to the left.
The nephron is the structural and functional
unit of the kidney.
The nephron has 3 primary functions:
o ______________________
o
______________________
o
______________________
The ______________________ filters
blood.

Reabsorption occurs along in the convoluted
tubules and Loop of Henle.
o
The ______________________ is
permeable to sodium ions and water.
o
The ______________________is
permeable to sodium, but not water.

Secretion occurs in the
_______________________________

Anything not reabsorbed (urea) becomes
the urine and is secreted through the
collecting duct.
3.4.g. How do filtration, secretion and reabsorption in the nephron help maintain a fluid and electrolyte
balance in the body?
Filtration eliminates toxins from blood, but allows for reduction of substances when blood levels are too
high. Selective reabsorption allows for maintenance of ions and blood sugar levels. Secretion allows one
to completely rid the body of unneeded and harmful substances.
3.4.h. How do the hormones ADH and aldosterone affect the nephron and the body’s overall water
balance?

Antidiuretic hormone is released from
which part of the brain?
o

________________________
ADH causes the collecting duct to
become _______________________
to water.

Water is conserved as it is
reabsorbed back into the body
tissues.

When water levels are high, ADH
release is inhibited. This is an
example of a ___________________
feedback loop.

Aldosterone is a hormone released
from the ______________________

Aldosterone causes the kidneys to
As the K+ concentration rises, sensors in the body detect this
increase and signal the adrenal cortex to release more
aldosterone into the bloodstream; the blood carries aldosterone
to the kidneys which, in turn, stop reabsorbing the K+ back into
the bloodstream, causing more K+ to be excreted in the urine.
conserve ______________ ions and
to excrete potassium ions (K+).

It promotes water conservation and
reduces urine output.
If the Na+ levels in the bloodstream are detected by the
body as being too low, aldosterone will be released so that
less Na+ is excreted in the urine; and if the water level in the
blood is too low (meaning that the cellular portion of the blood
is too concentrated), aldosterone will be released so that less
water is excreted in the urine.
3.4.i. What is urinalysis?


Urinalysis is completed by the analysis of 3 things:
o
__________________________________________
o
__________________________________________
o
__________________________________________
It involves a number of tests to detect and measure various
compounds that pass through the urine. It is considered a
medical intervention because it can be used to diagnose and
treat patients when abnormalities are found.
o Physical examination includes color and clarity.
o Chemical examination detects the following: specific
gravity, pH, presence of glucose, protein, ketones,
leukocytes, and other.
o Microscopic examination detects blood cells, bacteria,
and crystals.
3.4.j. How can the composition of urine provide clues about problems in other human body systems?
Normal composition of urine:
Water
Protein
Urea
Uric acid
Creatinine
Ammonia
Source
Ingested drink and food/ metabolism
Ingested food/tissue breakdown
Deamination (protein metabolism)
Metabolism of nucleotide bases
Metabolism of creatine phosphate
Deamination
Congestive heart failure; Injury to glomerulus or tubules from drugs, heavy metals, and viral infections;
diabetes, hypertension, and kidney stones can all cause kidney problems and can sometimes be
detected by urinalysis results.
Blood in urine can be a
sign of kidney disease,
kidney failure and kidney
stones.
White blood cells and
bacteria can be a sign
of an infection.
Glucose in the urine
can be a sign of
diabetes.
Ketones in the urine
can be a sign of
ketoacidosis from
excessive fat
metabolism.