Download This week`s lab will focus on the major endocrine

Module 10 Lab Worksheet: Endocrine System
Introduction
This week’s lab will focus on the major endocrine glands and the hormones they
secrete.
Objectives
Objectives for this week’s lab include: 1) Identify the location of the major
endocrine glands, 2) Map out the hormonal secretion of and influence of the major
endocrine glands, and 3) Identify the role of major endocrine hormones, and 4)
Describe the negative feedback mechanism to maintain homeostasis.
Overview
The endocrine system regulates the body’s actions and metabolic activity through
the use of chemical messengers called hormones. Hormones, produced by
endocrine glands, are secreted directly into the blood stream, travel throughout the
body and influence the actions and activity of various cells. It’s a complex
mechanism of how a hormone directly influences a cell but a cell needs to have a
specific receptor on its plasma membrane to bind a specific hormone. If a cell has a
specific hormone, it is referred to as a target cell.
Each hormone will have a unique and specific influence on cellular activity that may
include: reproduction activities, growth and development, electrolyte, water and
nutrient balance in the blood, metabolism and even influence our immune system.
Once a cell binds a hormone through its receptor, the response and impact of that
hormone can vary greatly. Some hormones have an almost instantaneous effect on
that cell (such as epinephrine, aka- adrenaline) to an effect that can last days to even
months (such as growth hormone).
Hormonal levels are maintained by a negative feedback mechanism. As hormonal
levels rise in the blood and affect the target cells, it causes a negative feedback loop
to initiate the inhibition of further hormone production and secretion from its
endocrine gland. Through this mechanism, hormonal homeostasis is maintained
within a very narrow range and is vital because any imbalances to hormonal levels
can cause drastic changes in the body’s physiology and can cause conditions such as,
type 2 diabetes and hypothyroidism.
Materials

Endocrine gland models
Pre-Lab Evaluation Questions
The pre-lab evaluation questions must be answered prior to lab and demonstrated
to your lab instructor. You must read through the assigned chapter readings, lab
introduction, objectives, overview and procedure to answer these questions.
Please cite your work for any reference source you utilize in answering these
questions.
1. In your own words, briefly describe how the endocrine system helps to
maintain homeostasis within the body.
2. Explain how the thyroid gland and the parathyroid gland help to maintain
homeostasis of blood calcium levels?
3. The thyroid gland also produces two hormones that influence our body’s
metabolism. What are those two hormones and the difference between
them? What element/molecule is vital to provide proper function to these
two hormones? In general and overall, what effect do these two hormones
have on the body’s function?
4. The adrenal cortex synthesizes over two dozen steroid base hormones
collectively called corticosteroids. Corticosteroids are also a class of
medications. Medically, what are corticosteroids, what are some examples of
corticosteroid medications, what conditions do they treat and what are the
complications of using them?
5. What is the importance of maintaining proper blood sugar levels? Why do
the cells need glucose and what hormone helps transport glucose into the
cells? What are normal blood sugar levels within humans? How does the
pancreas and liver maintain blood sugar homeostasis?
Part 01 Procedure: Endocrine Gland Location
1. Identify the location of the major endocrine glands in the diagram below:
Answers:
A)
F)
B)
G)
C)
H)
D)
I)
E)
J)
Part 02 Procedure: Endocrine Hormonal Secretion
1. Utilize “Appendix A” to map out the hormonal secretion and interaction of
the major endocrine glands hormones. Utilize the word bank in “Appendix C”
for to complete the chart. Demonstrated are the hormones “Growth
Hormone Releasing Hormone” and “Growth Hormone”.
2. Hint: The thyroid gland demonstrates two hormones that are secreted; one
hormone is regulated by the pituitary gland, which is demonstrated by the
line coming from the pituitary. Please record your answers below:
A)
B)
C)
D)
E)
F)
G)
H)
I)
J)
K)
L)
M)
N)
O)
P)
Q)
R)
S)
T)
U)
V)
W)
X)
Part 03 Procedure: Feedback Regulation of Hormones
1. Please match the appropriate hormone with the description provided in
“Appendix B” utilizing the word bank provided in “Appendix C”. Please
record your answers below.
A)
B)
C)
D)
E)
F)
G)
H)
I)
J)
Part 04 Procedure: Feedback Regulation of Hormones
1. Utilizing the interaction of the thyroid releasing hormone (TRH), thyroid
stimulating hormone (TSH), thyroxine (T4) and triiodothyronine (T3)
hormones please demonstrate the role of the negative feedback loop to
maintain proper thyroid hormone blood levels. Also, be able to explain how
a goiter would develop too.
Hypothalamus
Pituitary Gland
Thyroid Gland
2. The pancreas plays a very dynamic and vital role in our body’s ability to
maintain blood sugar homeostasis. Within your lab groups, discuss and
describe the following situations using appropriate medical terminology,
anatomy and hormones:
A) Your blood sugar levels are low, through what mechanism does your
body increase blood sugar levels?
B) Your blood sugar levels are too high, through what mechanism does your
body decrease blood sugar levels?
C) Why is it so vital for sugar to be transported from the blood vessels to the
cells of the body? (Think back to cellular respiration.)
D) How does the imbalance of regulating blood sugar levels over time lead to
the development of type 2 diabetes?
Post-Lab Evaluation Questions
The post lab evaluation questions must be completed prior to your submission of
the lab. Answers for these questions will be derived from the lab protocol, the
weekly concepts associated with the lab and possibly research content from the
book and/or online resources.
Please cite your work for any reference source you utilize in answering these
questions.
1. Please answer the following questions regarding a mini-case study on
Diabetes: Joe, a 58-year-old overweight male who is a widower, went
through a routine physical which demonstrated a Hemoglobin A1c blood test
of 8.5%. His previous A1c test 6 months ago was 6.5%. What is the
significance of this test and value? What is the most likely diagnosis (be
specific)?
2. The doctor asked Joe about his diet and lifestyle; if Joe were honest, how
would he have responded most likely? When the doctor asked Joe if he knew
what Diabetes was, he responded, “I’ve heard of it, it’s that thing where I
have to take some medication to fix it, right?”. In a paragraph, how would
you best explain what Diabetes is? Remember, you’re talking to a patient.
3. After your explanation, Joe responded, “Oh, I remember now. Will I have to
take those shots, before I eat all the time now?” How do you respond to Joe’s
question about treating this condition? Please include the lifestyle changes
and the possibility of oral medication and the use of insulin.
4. Joe seems to be starting to understand his condition and asks a great
question, “If I don’t do these sort of treatments, what can happen to me?”
Basically, Joe is asking about the various complications that can result from
uncontrolled blood sugar levels. What do you tell him? Include short and
long-term uncontrolled blood sugar level complications.
5. Joe sits quietly for a moment and then states, “I have a son in his late 20’s
who’s a bit overweight too, what can I tell him so he can stop this from
happening to him? What can I do to fix this problem too?”. How do you
respond to these questions?
Appendix A
Hypothalamus
GHRH
A
B
E
D
C
Anterior
Pituitary
Posterior
Pituitary
G
F
GH
Mammary
Glands
Thyroid
Gland
J
I
H
K
L
Adrenal Glands
(adrenal cortex)
Gonads:
Ovaries
Testes
M
P
Adrenal Glands
(adrenal medulla)
R
O
Q
S
T
N
Parathyroid
Gland
Pineal
Gland
V
U
Pancreas
Gland
W
X
Appendix B
Descriptions of hormones
A) Which hormone will assist the body in lowering blood sugar levels?
B) Which gland synthesizes a hormone that helps regulate the sleep cycle?
C) Which hormone leads to water conservation (reabsorption) in the kidneys
and is produced by the hypothalamus?
D) Which hormone lowers blood calcium levels by decreasing absorption of
calcium and stimulates osteoblast activity in bone tissue?
E) Which hormone(s) has/have potent anti-inflammatory effects, decreases the
immune system function and is largely secreted during times of stress?
F) Which hormone secreted by the adrenal cortex helps regulates blood
pressure by increasing reabsorption of various ions and water in the kidneys
leading to increased water retention and ultimately increased blood
pressure?
G) Which hormone acts upon the liver to assist in raising blood sugar levels?
H) Which hormone stimulates ovulation (release of an egg from the ovary)
during the middle of the menstrual cycle?
I) Which hormone stimulates the production of breast milk post-birth?
J) Which hormone will stimulate the testes to produce sperm?
Appendix C
Word bank for Part 02 and Part 03 Procedures

Adrenocorticotrophic hormone (ACTH)

Aldosterone

Antidiuretic hormone (ADH)

Calcitonin

Corticotropin-releasing hormone (CRH)

Cortisol

Epinephrine (adrenaline)

Estrogen

Follicle stimulating hormone (FSH)

Glucagon

Glucocorticoids

Gonadocorticoids (androgens)

Gonadotropin-releasing hormone (GnRH)

Growth Hormone

Growth hormone-releasing hormone (GHRH)

Insulin

Luteinizing hormone (LH)

Melatonin

Mineralcorticoids

Norepinephrine (noradrenaline)

Oxytocin

Parathyroid hormone

Prolactin

Progesterone

Testosterone

Thyroid hormone (T3 and T4)

Thyroid stimulating hormone (TSH)

Thyrotropin-releasing hormone (TRH)