Lab 1
Functional Anatomy of the Endocrine Glands
Identifying the Endocrine Organs
Examining the Microscopic Structure of Endocrine Glands
Thyroid gland - colloid-filled follicles, follicle cells, and parafollicular cells.
Text Figure 18-10.
Parathyroid gland - chief cells.
Text Figure -18-12
Adrenal gland - cortex and medulla.
Text Figure 18-15
Pancreas - islets of Langerhans and acinar cells.
Text Figure 18-16
Endocrine System Physiology:
PhysioEx on Canvas
The simulation you need can be accessed through PhysioEx on Canvas.
Name____________________________
Lab Section ________________
Turn these sheets in for a grade. Due at next class or meeting.
1. Draw and label the following samples: Use colored pencils and a ruler. Print the
labels. Use the 10 X or 40X lens
Thyroid Gland: label colloid, parafollicular cells, follicle cells
Total Magnification _____ X
Pancreas: label islet cells and acinar cells
Total magnification _____ X
2. Hormonal Action: Wet Lab Movie - Watch this movie at home and answer the
following questions.
Hormonal Action – Movie - Endocrinology Experiments
To access the movie online (via DSL or cable)
Go to A and P II in Canvas
Select Videos and select Endocrinology Experiments
View the first two experiments only – pituitary hormones and insulin
Movie - Experiments in Hormonal Action
1. Pituitary Extract and Frog Ovulation.
a. What are the two main hormones of interest in the frog pituitary extract?
________________ and _______________
b. What is the role of pituitary extract in the frog?
c. What is the control frog in the experiment?
d. Do the data support the hypothesis that pituitary extract is necessary for
ovulation?_____
e. Explain your answer (2 points).
2. Effects of Hyperinsulinism.
a. Describe the fish swimming behavior when it is first put in the water containing
insulin,( before insulin has an effect) .
b. Describe the fish swimming behavior after swimming in the insulin and water for
a few minutes.
c. Where does insulin enter into the fish?
d. What happens when the fish is put in water with glucose, and why?
3. Endocrine System Physiology: Computer Simulation PhysioEx Link
Use PhysioEx Simulation in Canvas 10_EndoPhysio.swf
Insulin and Diabetes Part 1
Obtaining a Glucose Standard Curve
To begin, select Insulin and Diabetes-Part 1 from the Experiment menu .
On the right side of the opening screen is a special spectrophotometer. The
spectrophotometer is one of the most widely used research instruments in biology. It is
used to measure the amounts of light of different wavelengths absorbed and transmitted
by a pigmented solution. In Part II, you will use the spectrophotometer to determine how
much glucose is present in blood samples taken from two rats. Before using the
spectrophotometer, you must obtain a glucose standard curve so that you have a point
of reference for converting optical density readings into glucose readings, which will be
measured in mg/deciliter (mg/dl). To do this, you will prepare five test tubes that contain
known amounts of glucose: 30 mg/dl, 60 mg/dl, 90 mg/dl, 120 mg/dl, and 150 mg/dl,
respectively. You will then use the spectrophotometer to determine the corresponding
optical density readings for each of these known amounts of glucose. Information
obtained in Part I will be used to perform Part II.
Also on the screen are three dropper bottles, a test tube washer, a test tube dispenser (on
top of the washer), and a test tube incubation unit with numbered cradles that you will
need to prepare the samples for analysis.
1. Click and drag the test tube (on top of the test tube washer) into slot 1 of the incubation
unit. You will see another test tube pop up from the dispenser. Click and drag this second
test tube into slot 2 of the incubation unit. Repeat until you have dragged a total of five
test tubes into the five slots in the incubation unit.
2. Click and hold the mouse button on the dropper cap of the glucose standard bottle.
Drag the dropper cap over to tube 1. Release the mouse button to dispense the glucose.
You will see that one drop of glucose solution is dropped into the tube.
3. The dropper will automatically slide over to each of the remaining samples. Notice that
each subsequent tube will automatically receive one additional drop of glucose standard
(i.e., tube 2 will receive two drops, tube 3 will receive three drops, tube 4 will receive
four drops, and tube 5 will receive five drops).
4. Click and hold the mouse button on the dropper cap of the deionized water bottle.
Drag the dropper cap over to tube 1. Release the mouse button to dispense the water.
Notice that four drops of water are automatically added to the first tube.
5. The dropper will automatically slide over to each of the remaining samples. Notice that
each subsequent tube will receive one less drop of water than the previous tube (i.e., tube
2 will receive three drops, tube 3 will receive two drops, tube 4 will receive one drop, and
tube 5 will receive no drops of water).
6. Click on the Mix button of the incubator to mix the con- tents of the tubes.
7. Click on the Centrifuge button. The tubes will descend into the incubator and be
centrifuged.
8. When the tubes resurface, click on the Remove Pellet button. Any pellets from the
centrifuging process will be removed from the test tubes.
9. Click and hold the mouse button on the dropper cap of the enzyme color reagent
bottle. Still holding the mouse but- ton down, drag the dropper cap over to tube 1. When
you re- lease the mouse, you will note that five drops of reagent are added to the tube.
10. The dropper will automatically slide over to each of the remaining samples.
11. Now click Incubate. The tubes will descend into the incubator, incubate, and then
resurface.
12. Using the mouse, click on Set Up on the spectrophotometer. This will warm up the
instrument and get it ready for your readings.
13. Click and drag tube 1 into the spectrophotometer (above the Set Up button) and
release the mouse button. The tube will lock into place.
14. Click Analyze. You will see a spot appear on the screen and values appear in the
Optical Density and Glucose displays.
15. Click Record Data on the data collection unit.
16. Click and drag the tube into the test tube washer.
17. Repeat steps 13–16 for the remaining test tubes.
18. When all five tubes have been analyzed, click on the Graph button. This is the
glucose standard graph, which you will use in Part II of the experiment.
19. Leave the standard curve graph on the screen and proceed to the next section.
Insulin and Diabetes Part II
Measuring Fasting Plasma Glucose
To undergo the fasting plasma glucose (FPG) test, patients must fast for a minimum of 8
hours prior to the blood draw. Plasma samples will be measured in the
spectrophotometer, and the glucose standard curve generated in Part I will be used to
determine fasting plasma glucose levels in the five patient samples. A patient with two
separate FPG tests greater than or equal to 126 mg/dl is diagnosed with diabetes. FPG
values between 110 and 126 mg/dl are indicative of impairment or borderline impairment
of glucose uptake by cells. FPG values less than 110 mg/dl are normal.
If the FPG is borderline, another test, the oral glucose tolerance test (OGTT), is
performed. In this test, the patient also fasts for 8 hours. The patient then ingests a
concentrated glucose solution, and blood is drawn and tested at periodic intervals.
Glucose and sometimes insulin levels are measured. The 2-hour glucose level should be
below 140 mg/dl. A 2-hour OGTT level between 140 and 200 mg/dl indicates impaired
glucose tolerance, and a level above 200 mg/dl confirms the diabetes diagnosis.
Individuals with impaired fasting glucose values and impaired glucose tolerance are at a
higher risk of developing type 2 diabetes. If a patient is pregnant, an FPG value greater
than 110 mg/dl could indicate gestational diabetes and a strict diet should be followed for
the remainder of the pregnancy.
Draw the standard curve you generated using a ruler. For each of the optical densities
use a ruler to determine where a line from the optical density would cross the standard
curve. Where your line crosses the standard curve, make a mark and read the glucose
concentration from the X-axis.
The example below shows the glucose concentration for and optical density of 0.5.
The glucose concentration is about 65 mg/dl.
Construct your Standard Curve on this graph.
Draw Your Standard Curve Here.
Record your glucose readings for each test tube here:
Standard Curve
Sample 1: glucose concentration of _______________ mg/deciliter
Sample 2: glucose concentration of _______________ mg/deciliter
Sample 3: glucose concentration of _______________ mg/deciliter
Sample 4: glucose concentration of _______________ mg/deciliter
Sample 5: glucose concentration of _______________ mg/deciliter
Patient Samples
These are the optical density readings for the 5 samples. Mark these on the standard
curve and record the glucose concentration below.
Sample 1:
0.71
Sample 2:
0.81
Sample 3:
0.86
Sample 4:
0.83
Sample 5:
0.96
Sample 1: glucose concentration of _______________ mg/deciliter
Sample 2: glucose concentration of _______________ mg/deciliter
Sample 3: glucose concentration of _______________ mg/deciliter
Sample 4: glucose concentration of _______________ mg/deciliter
Sample 5: glucose concentration of _______________ mg/deciliter
For which patient(s) were the glucose reading(s) in the normal
range?
For which patient(s) were the fasting plasma glucose reading(s) in the diabetic range?
For which patient(s) were the fasting plasma glucose reading(s) in the impaired range?
What recommendations would you make to a patient with an impaired FPG value who
also tested in the impaired range with the oral glucose tolerance test?
Patient 3 is pregnant; how might this change the diagnosis? What recommendations
would you make to this patient?
For the Lab Exam
Endocrine System
 Identify on Figures
o Nuclei in hypothalamus
o Hypophyseal portal system
o Hypothalamic-hypophyseal tract
o Anterior pituitary
o Posterior pituitary
 Identify terms from Figure
o Pineal gland
o Hypothalamus
o Pituitary gland
o Thyroid gland
o Parathyroid gland
o Thymus
o Adrenal glands
o Pancreas
o Ovary
o Testis
 Slides
o thyroid gland slide – colloid, follicle, follicle cell, parafollicular cell
o pancreas slide – islets of Langerhans, acinar cells
o adrenal gland slide – cortex, medulla