LAB
THE ENDOCRINE SYSTEM
The endocrine system contains some of the most elegant and mysterious mechanisms of all the body
systems. The endocrine system controls reproduction, growth and development, body defenses, metabolic
processes, and blood chemistry.
Hormones circulate in the blood until reaching the target organs upon which they are designed to act,
where they bind with the awaiting cells and immediately begin to influence the internal machinery of those
cells.
Objectives:
• Observe the microscopic anatomy of the major endocrine glands.
• Be able to identify the major endocrine glands and the hormones they secrete.
• Learn the target organs and actions of the major hormones.
You will be answering questions and making sketches on the answer sheet. Use your textbook to
help find answers and use the Histology Index in on the left panel of Blackboard.
You can see that you can sort the slide images in different ways. It might be most useful to you to
use the A-Z method for this exercise. Be sure to activate the labels and use the “piece of the pie”
method for drawing complex slides.
1. PITUITARY GLAND
View the pituitary gland at low and high magnification. At low magnification, sketch the overall
gland and label the anterior and posterior regions. At high magnification, sketch and label what you
see.
Follow the directions on the answer sheet for labeling and highlighting the figure and answer any
questions.
2. THYROID GLAND
View the thyroid gland at medium magnification. Sketch and label a follicle surrounded by c-cells.
These latter cells are also called parafollicular cells.
Follow the directions on the answer sheet for answering any questions.
3. PARATHYROID GLAND
View the parathyroid gland at medium and high magnification. At medium magnification, sketch
and label what you see.
Respond to questions on answer sheet.
4. ADRENAL GLAND
View the adrenal gland at medium and high magnification. At medium magnification, sketch and
label what you see.
Respond to questions on answer sheet.
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Name___________________________________
_______________________
Lab Questions
GENERAL
1. Provide one example for each way endocrine glands are stimulated to release their hormones.
2. What is the most common cause of hypersecretion by endocrine organs?
PITUITARY
functions.
3. Name the two hormones secreted by the posterior pituitary and state their functions..
4. For each target gland/tissue in the figure below, name the correct anterior pituitary hormone that
acts on it. Then highlight the three tropic hormones.
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5. What are tropic hormones?
6. Both the anterior and posterior pituitary glands release hormones, but the posterior pituitary is not
an endocrine gland. What is it?
7. The anterior pituitary is often referred to as a master gland, but what is its master?
8. Labeled sketch of pituitary gland at high magnification:
THYROID AND PARATHYROID
9. Name the active form of the hormone secreted by the thyroid follicles and state its function.
10. Name the hormone secreted by the c-cells and state its function.
11. Which hormone increases blood calcium levels? Where is it produced?
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12. Which hormone reduces blood calcium levels? Where is it produced?
13. How are the thyroid and parathyroid glands linked anatomically?
14. Where do Americans obtain most of the iodine they need for proper thyroid function?
15. Labeled sketch of thyroid gland follicle and c cells at medium magnification:
16. To what does the latin root “para” refer?
17. Labeled sketch of parathyroid gland at high magnification:
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ADRENAL
18. Name and describe the functions of the three major groups of steroid hormones the adrenal cortex
produces.
19. Fill in the blanks (see page 323):
Renin is produced in the _______________ when blood pressure _______________. It triggers a
series of reactions that result in the release of __________________, which in turn causes the
release of __________________.
20. List the two major hormones secreted by the adrenal cortex (Hint: one is a glucocorticoid and the
other is a mineralocorticoid) and state their functions.
21. List the two hormones of the adrenal medulla involved in the stress response.
22. Potentially, what are five results of long-term stress?
23. Describe the scenarios for type I and type II diabetes.
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