LABORATORY NO.
10
ENDOCRINE SYSTEM
Scope of Laboratory Activity:
This laboratory exercise consists of four (4) worksheets:
Worksheet no. 1 Major endocrine glands and its gross anatomy
Worksheet no. 2 Major Endocrine organs and their Hormones
Worksheet no. 3 Hormone Functions
Worksheet no. 4 Control mechanism of endocrine secretion
Overview
In this laboratory activity, you will be able to further enhance your understanding about the
various endocrine organs, their hormones and their mechanism of secretion.
Objectives
After completing this exercise, you should be able to:
1. Recognize the gross structure of the major endocrine glands
2. Name the major endocrine organs and its secreted hormones
3. Identify the functions of each hormone in each endocrine gland
4. Explain the negative feedback mechanism of hormonal secretion
Materials None
Worksheet no. 1 Major endocrine glands and its gross anatomy
A. Identify the 10 major endocrine glands on a human torso using the choices below.
adrenal glands • hypothalamus • ovaries • pancreas • parathyroid glands • pineal gland • pituitary
gland or hypophysis • testes • thymus • thyroid gland
Figure 10. 1 Anterior view of
Anterior the of
view Major Endocrine Glands
human torso
B. Answer the following with not more than 4 sentences.
1. Briefly explain the difference between the endocrine and nervous systems which are
considered the major regulating systems of the body.
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2.What is a hormone?
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3. Compare and contrast endocrine and exocrine glands.
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C. Label the diagrams below using the choices from the box. Write your answer beside each
corresponding number.
Anterior pituitary Right lobe of thyroid gland
Hypothalamus Trachea
Infundibulum Left parathyroid glands
Posterior pituitary Right parathyroid glands
Isthmus of thyroid gland Thyroid gland
Left lobe of thyroid gland trachea
Figure 10. 2 Hypothalamus and Pituitary Glands
Figure 10.3 Anterior view of the thyroid Gland
Figure 10. 4 Parathyroid Gland
Worksheet no. 2 Major Endocrine organs and their Hormones
A. Watch the video on effects of hyperinsulinism on the goldfish and answer the following
questions. Click the link below https://youtu.be/rHgsiWeYqqI.
1. About how long did it take for the fish to become comatose?
2. What activities did you observe before it became comatose?
3. Briefly explain what happened to the fish when immersed in insulin solution.
4. What happened to the fish when it was transferred to beaker B?
5. In humans, what endocrine gland is responsible for these events?
B. Write the name of the endocrine gland that secretes the following hormones.
Anterior Pituitary gland Gonads
Posterior Pituitary gland Adrenal glands
Thyroid gland Pineal gland
Parathyroid glands Thymus
Pancreas
Hormone Endocrine Gland
ACTH
ADH
Aldosterone
Androgens
Calcitonin
Cortisone; cortisol
Epinephrine
Estrogen
FSH
MSH
Thymosin
Glucagon
Melatonin
PTH
Worksheet no. 3 Hormone Functions
Match each hormone to its respective function. Write the correct answer in the space provided.
Use the choices below.
ACTH ADH aldosterone androgens calcitonin cortisol epinephrine estrogen FSH glucagon hGH
insulin LH melatonin MSH NE OT PRL progesterone PTH T3 T4 testosterone thymosin TSH
Hormone Function Hormone
Stimulates uterine contractions and milk ejection
Stimulates secretion of hormones by adrenal cortex
increasing reabsorption of water in blood and
decreasing urine production
Triggers ovulation and stimulates secretion of estrogen
and progesterone
Increases blood calcium levels
Promotes fight or flight response
Stimulates production and secretion of milk
Increases resistance to stress, increases blood glucose
levels and decreases inflammation
Helps set biological clock
Helps regulate menstrual cycle
Stimulates secretion of thyroid hormones
Worksheet no. 4 Control mechanism of endocrine secretion
A. Sometimes more than one tropic hormone is involved in a cascade of events involved in
negative feedback regulation. In Figures a and b, a stimulus disrupts homeostasis and initiates
release of hormones in a specific order to return to homeostasis. Answer the questions associated
with each figure.
(b)
(a)
In figure a,
Identify endocrine glands 2 & 3 ______________ &_____________
Identify hormones 2 & 3 __________ & __________
What are the 2 tropic hormones?
In figure b,
Identify endocrine glands 2 & 3 ______________ &_____________
Identify hormones 2 & 3 __________ & __________
What are the 2 tropic hormones?
B. Choose one from the above figures (a &b) and explain the negative feedback regulation
that is happening to maintain homeostasis.
Reference:
Allen, C. & Harper, V. (2009). Laboratory Manual for Anatomy and Physiology. 3rd ed.
Hoboken, NJ: John Wiley
