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Endocrine Lab:
See Content of Chapter 17
Overview:
The endocrine system is a diffuse system, scattered throughout the body. It is composed of
numerous organs that serve strictly an endocrine function (i.e., secretion of hormones) and
many endocrine tissues or cells that are part of larger organs. All endocrine organs and
tissues are glands that are ductless. They secrete these chemical messengers, hormones,
into the bloodstream to travel to distant target tissues where each hormone exerts its
actions.
Hormones are chemical signals the body uses to direct biological actions. Each hormone
can only stimulate a response in cells that have receptors for that hormone. The location of
the receptor, membrane bound or intracellular, is dictated by the chemical nature of the
hormone. The body tightly regulates the overall receptor numbers at a target tissue;
without receptors hormones have no ability to cause cells to change their function.
Many homeostatic mechanisms are tightly regulated by hormone actions. Blood glucose
levels are an example of such a mechanism.
This lab has two major components: an anatomical overview and a physiology exercise.
Remember that you will probably need to spend time in open lab to move from familiarity
with the information to understanding the where and how our endocrine system work.
Anatomy Learning Objectives:
1. Students will be able to identify the endocrine glands on the models, figures and
cadaver described in this lab.
2. Students should be able to name the main hormones secreted by each of the
endocrine glands studied.
3. Students should be able to differentiate the various histological structures on the
endocrine slides listed below.
ENDOCRINE GLAND ANATOMY:
Major and minor endocrine glands of the body are part of the way our bodies communicate
to regulate and control growth, metabolism and sexual development and function. (Be sure
that your laboratory period is not spent looking at the book and a torso model, much of this
type of review can be completed in open lab.)
Exercise 1: Organ overview
Part 1: Working in a group of three to four students, gather around a torso model, refer to
figure 17.1, and identify the following major endocrine organs.
1.
2.
3.
Pituitary gland
Pineal gland
Pancreas
4.
5.
6.
7.
8.
Adrenal gland
Thyroid gland
Parathyroid gland
Ovary
Testes
Once organ identification is complete, fill in the function of the hormones secreted by each
gland on the endocrine chart that is part of the laboratory worksheet. In addition to
identifying the function, list any tropic hormones that promote the release of the hormone.
Part 2: As our knowledge of the endocrine system expands, more and more organs appear
to have some endocrine gland function. Some of the glands on the torso model would be
considered minor glands. Identify these minor endocrine glands on the torso model,
cadaver and figure 17.1:
1.
Kidney – erythropoietin
2.
Heart -- atrial natiuretic hormone
3.
Liver – angiotensinogen (precursor to Angiotensin II)
4.
Thymus -- thymosins
Again return to the endocrine chart and describe the function of the hormones listed for
the minor endocrine tissues.
Part 3: Finally, a quick nervous system review of the hypothalamus: Open your book to
page 515 and use figure 14.2 as a reference. Examine a model of the brain and identify the
hypothalamus on its inferior surface. The hypothalamus is located in the lower central part
of the brain. Find the hypothalamus on the diagram. It is shaped like a funnel that forms
the floor and walls of the third ventricle of the brain (figures 14.2 and 14.12b).
With its intimate tie to the posterior pituitary via the nerve tracts and is connection to the
anterior pituitary via the hypothalamohypophyseal portal system (figure 17.4 a and b, page
639), the hypothalamus is a major control center for many of the hormones in the body. It
secretes tropic hormones that stimulate or suppress the release of hormones from the
anterior pituitary, thereby playing a role in homeostasis. The hypothalamus plays an
important role in the regulation of satiety, metabolism, sex drive and body temperature.
SPECIFIC ENDOCRINE GLANDS: For the remaining anatomical review exercises, you will
need to find the individual structure of the endocrine glands and look at the histology of
each.
Exercise 2: Pituitary Gland
Some of the brain models have a pituitary gland
depicted, see the very pink bean-sized structure
identified by the blue arrow is on. The pituitary gland
(figure 17.4a and b, p. 639) is suspended from the floor
of the hypothalamus by a stalk (i.e., infundibulum) and is
housed in a depression in the sphenoid bone (i.e., sella turcica of the sphenoid bone). It is
physically smaller than a marble, more like a kidney bean in shape and size. It is composed
of two structures: the adenohypophysis (i.e., anterior pituitary) and the
neurohypophysis (i.e., posterior pituitary). These two structures have independent
origins developmentally, and have distinct physiological functions.
View figure 17.4a and note that neurons extend from two brain nuclei (i.e., paraventricular
nucleus and suprapotic nucleus) in the hypothalamus to terminate in the posterior
pituitary. This indicates that the secretions from the posterior pituitary are
neurosecretions and are sometimes called neurohormones. The paraventricular nucleus
is responsible for the synthesis of oxytocin (which promotes uretine contraction or milk
ejection), while the supraoptic nucleus produces antidiuretic hormone (to counter
dehydration and is involved in blood pressure regulation).
The anterior pituitary is composed of glandular tissue and is involved in the release of 6
different hormones directly into the bloodstream. Tropic hormones released by the
hypothalamus into the bloodstream control the secretion of anterior pituitary hormones.
Look at figure 17.4b and note the extensive capillary networks associated with the
hypothalamus and anterior pituitary. If we follow the superior hypophyseal artery, it
branches into a primary capillary bed right at the base of the hypothalamus. This capillary
bed is drained by portal venules that terminate in a second capillary bed surrounding the
anterior pituitary. This arrangement of vessels connecting two capillary beds in a series is
called a portal system. And this specific one is called the hypothalamo hypophyseal
portal system.
Part of learning the anatomy of any system is to look at the tissues at a microscopic level.
This examination reveals specific cellular structures and tissue organization you will be
required to know. Remove slide 34 from the slide box and place on a piece of white paper.
Notice with your naked eye the pituitary gland slide has two distinct parts. The darker
stained region is the anterior pituitary. The lighter stained region is the posterior
pituitary. Now, place the slide on the stage of the microscope and focus on low power.
(Remember that you always want to start on low power.) Scan the slide and find the
junction between the anterior pituitary and the posterior pituitary. Now focus on this
junction on high power. Notice that the cells of the anterior pituitary are relatively
cuboidal in shape and have relatively large nuclei. Remember the anterior pituitary is
glandular in nature.
Now focus on the opposite side of the junction. This side has an almost fibrous appearance
with numerous small dark nuclei interspersed. Recall that the posterior pituitary is an
extension of the hypothalamus – brain tissue. It is composed of bundles of axons (the more
fibrous appearance -- tracts) intermixed with glial cells (the darker, small nuclei) (figure
17.5, p. 636).
In the space provided on the worksheet, draw what you see in your field of view for the
anterior pituitary and posterior pituitary. Then compare your drawing to that of your peers
and also the website hyperlink for the pituitary. (This is not about how well you draw,
rather it is the actual act of drawing that helps you remember the structures that you are
observing at a cellular/tissue level.)
Go to the endocrine chart on the worksheet and fill in the functions of the hormones of the
anterior (6) and posterior pituitary (2). Most of the hormones of the pituitary are
controlled by negative feedback, with at least one notable exception, oxytocin. Use your
text to review these hormones.
Exercise 3: Thyroid Gland
The thyroid gland is one of the easiest glands to palpate. Run your fingers down your
trachea towards your manubrium (the broad upper part of the sternum). You should feel
the cartilaginous supports of your trachea and you should feel the thyroid gland that spans
this structure just caudal to the thyroid cartilage of the larynx. While our palpation is kind
of crude in nature, practiced physicians learn to detect gland texture as well as size with
just their fingers.
The gland itself is butterfly shaped where the two wings create the glands bulk as it wraps
the trachea. The two lobes (i.e., the left and right lobes) are attached inferiorly by a
bridge-like structure called the isthmus (figure 17.9a).
Remove slide #4 from the slide box, place the slide on the stage of the microscope and
focus on low power. Quickly advance to high power. The most notable feature of the slide
is the numerous functional units interspersed throughout the gland called thyroid follicles
(figure 17.9b). The walls of the follicle are composed of simple cuboidal epithelial tissue.
The lumen of the follicle is filled with a protein-rich colloid precursor of the thyroid
hormones. The follicular cells encompass the follicle and secrete thyroxine (i.e., T4 or
tetraiodothyronine) and triiodothyronine (i.e., T3). These hormones are collectively called
the thyroid hormones.
In the space provided on your worksheet draw what you see in the field of view for the
thyroid gland. Label the thyroid follicle with the colloid inside of it and the follicular cells.
There are also clusters of cells located between the follicles called parafollicular cells.
These cells, also called C cells, are hard to distinguish on a normal slide, but you need to
know that these cells exist and are the source of the hormone calcitonin which helps
prevent hypercalcemia. Label the parafollicular cells in your diagram as well. Once
complete, compare your diagram to the website illustration and to the diagrams of your lab
partners.
Exercise 4: Pancreas
The pancreas is an elongate glandular structure (about the texture of cottage cheese –
when looking at the cadaver). It is located below and behind the stomach (figure 17.12a).
The bulk of the gland is exocrine tissue involved in the release of digestive enzymes into
the small intestine through the pancreatic duct. Only a small portion of this gland is
devoted to endocrine actions.
Remove slide # 20 from the slide box and focus on low power. Quickly step up to high
power. The pancreas contains both exocrine and endocrine cells. Scan the slide and isolate
a portion that shows the darker, exocrine tissue with interspersed with clusters of lighter
stained cells of the endocrine functions derived in the pancreatic islets (figure 17.12b,c).
The exocrine tissue is composed of tightly packed serous acini that appear like rather puffy
cell collections. The histological stain used is specific for the rough endoplasmic reticulum
(i.e., RER), the organelle used to make enzymes and proteins in the cells. Because the
serous acini secrete more digestive enzymes, they have more RER and are therefore
stained darker.
The islet cells are less enlarged and are paler in color. A fine capsule that allows it to be
distinguished as a unit surrounds the entire islet, but you will not be able to see this
capsule specifically under the light microscope, instead you will only see that the endocrine
cells are packed together. There are several cell types within each islet including the alpha
cells which secrete glucagon, that increases blood glucose if needed (prevent
hypoglycemia), the beta cells which secrete insulin that decreases blood glucose if needed
(prevent hyperglycemia), and the delta cells that secrete somatostatin which helps regulate
digestion as well as secretion of insulin or glucagon. But to identify these individual cells
there would have to be additional staining. Go to the endocrine chart on the worksheet and
fill in the hormones of the pancreatic islets.
Draw the histology of the pancreas as seen in the microscope field of view. Label the
serous acini of the exocrine pancreas and the pancreatic islets. Then compare your
diagram to that of the web picture and that of your classmates.
Exercise 5: Adrenal Gland
The adrenal glands are small, almost triangular shaped glands that are superior to the
kidneys (figure 17.11a). The glands are about the size of a hazel nut. Like the pituitary, the
adrenal gland develops from two distinct glands in the embryo, both with endocrine
functions. Identify this gland on the torso model and from diagrams from your book.
Remove slide # 36 from the slide box and focus on low power. The entire gland is typically
surrounded by a layer of adipose tissue. The capsule surrounds the outside of the gland
proper. Focus on the cortex of the adrenal gland. The outer layer, called the cortex, is the
larger of the layers consisting of about 80-90% of the entire structure, while the inner
medulla about 10% of the entire structure. The cortex surrounds the deep medullary
tissue and is a structurally diverse tissue that can be divided into three layers (from outside
toward the medulla): zona glomerulosa, zona fasciculate and zona reticularis (figure
17.11b). You are not responsible for identifying the specific cortical layers histologically,
but rather should know that the adrenal cortex is involved in secreting three classes of
steroid hormones: androgens, minerocorticoids and glucocorticoids. The medulla is
both an endocrine organ and a ganglion of the sympathetic nervous system. Chromaffin
cells make up this ganglion and are responsible for secreting the catecholamine hormones
(e.g., epinephrine, norepinephrine and dopamine). Note the highly vascular nature of the
adrenal medulla and ponder how these blood vessels are needed to carry catecholamines
to the body following secretion at these modified sympathetic nerve endings. Fill these
hormones in on the endocrine chart of the worksheet.
Exercise 6: Gonads
The ovary is not only a reproductive organ responsible for oogenesis, but is also an
endocrine organ releasing estrogens and progesterone (figure 28.1). The ovaries are small,
almond-shaped organs. Identify the ovary on the torso model and from the figure in your
text. The ovary has a cortex and medulla, like many of the other organs examined (figure
28.2). The primary hormones of the ovary are estrogens, progesterone and inhibin. Fill
these in on the endocrine chart.
The ovary is surrounded by a fibrous capsule and the cortical stroma is where the ovarian
follicles can be found. The follicles are a collection of epithelial cells and an oocyte
surrounded by a capsule called the theca. The follicles can be at various stages of
development, although most are primordial follicles. (This differs from the diagram in
your book that is illustrating the various stages of development the follicles progress
through indicated by the series of black arrows.) Figure 17.13a is a histological view of a
mature ovarian follicule. At this stage of development the oocyte (collectively includes the
egg and the egg nucleus) is obvious. Surrounding the oocyte are layers of granulosa cells
that secrete estrogens. Surrounding the granulosa cells are the theca. The medulla is
again the inner region of the organ that is composed of connective tissue and is also highly
vascularized.
Remove slide #40 from the slide box and focus using low power. At this point you should
be able to see the entire ovary section. Notice the cortex and the medulla. Now advance to
100X magnification. Focus on the cortex and look for a good example of a mature follicle.
Isolate that follicle and examine it under 400x magnification. At this point you should be
able to identify the cortical stroma and the isolated follicle as well as the oocyte, granulosa
cells and theca. Draw what you see in the field of view of the microscope and label these
structures.
Return to 100x magnification and find a cluster of darker cells slightly below the follicle
layer. This cell cluster is a corpus luteum and is responsible for progesterone secretion
that assists in maintaining pregnancy. Again draw what you see in the field of view of the
microscope and label this structure. Compare your diagram with that of the study group
across the table.
The testes, like the ovary, has two functions: spermatogenesis and sex hormone
production. Testes are paired organs housed in the scrotum. They are about the size of
walnuts gross structure (figure 27.9a,b,c). In terms of an endocrine organ, the testes must
be examined histologically.
Remove slide #12 from the slide box and focus under low power. The most striking feature
of this slide is the numerous seminiferous tubules of the testes (figure 1713b). The
outermost tissue is the tunica albuginea that surrounds the testicle proper. Advance to
high power and focus on a single seminiferous tubule (figure 17.13b). Sperm cells are
produced in these chambers and as mature spermatids would be found in the luminal area.
The outermost layer of the seminiferous tubule is the germinal epithelium, but it is hard
to distinguish from the other cells that are the sustentacular cells (i.e., Sertoli cells).
These sustentacular cells secrete inhibin. Inhibin exerts negative feedback on the pituitary
to suppress FSH secretion. In between the seminiferous tubules are interstitial cells (i.e.,
Leydig cells) that secrete testosterone. Aside from a positional arrangement (i.e., between
the seminiferous tubules), these interstitial cells are not distinguishable based on
histological staining. Draw what you see in the field of view and label the seminiferous
tubules, germ cells and interstitial cells. Then fill in the hormones of the testes in the
endocrine table.
Exercise 7: Other Endocrine Glands
The pineal gland is a brain endocrine gland located near the posterior end of the corpus
callosum. It is actually attached to the roof of the third ventricle and is considered part of
the epithalamus (figure 14.2, p. 515). This gland is associated with establishment of the 24hour circadian rhythms our bodies experience with the light and dark cycles. Melatonin is
a specific hormone of this gland and may be involved in sleep patterns and in the timing of
puberty. Consider the function of this gland when wake up at 7am for your 8am class on
Saturday morning or when you experience Jet Lag after returning from a vacation in
Europe. Locate this gland on a brain model and fill in the endocrine chart on your
worksheet.
The thymus is an immune organ that also has endocrine functions. The organ undergoes
considerable changes with age reaching its peak size at puberty and then undergoes
involution. It lies in the anterior mediastinum and can extend up to the thyroid gland and
down towards the 4th and 5th costal cartilage (figure 17.8a and b). This gland is not obvious
on the torso models, so you only need to know it from the above diagrams.
The thymus is the site for T cell (lymphocytes) development and maturation. Hormones of
the thymus are thymosin, thymopoietin, thymulin and interleukins all involved in the
development of a mature immune system. Fill these in on the endocrine chart on your
worksheet.
ENDOCRINE PHYSIOLOGY
Physiology Objectives: (On average, this exercise should take the second half of the class
period.) Upon completion of this exercise students will be able to:
1. Define pre-diabetes and diabetes.
2. Predict pre-prandial and postprandial values for individuals with diabetic, prediabetic and normal blood glucose concentrations.
3. Operate a blood glucose meter, record and interpret results.
4. Display a functional knowledge of diabetes.
Blood Precautions:
It is common practice in the lab to simply assume that every blood, tissue, or fluid sample
you deal with is tainted with something harmful. As a result it is important to remember to
wear disposable gloves whenever you are handling blood or any materials that have come
into contact with blood (even if it is your own). In addition, it is important to wash your
hands before leaving the lab after you have been working with blood. In addition to proper
personal protection (i.e., gloves) it is important to clean any surfaces that may have become
contaminated with blood (microscopes, bench tops, equipment, etc…). Disinfecting
solutions will be supplied by the department and will be in the lab for your use. Anything
that comes in contact with blood must be disinfected and materials that will be disposed of
(microscope slides, gloves, lancets) must be placed in designated “biohazard” receptacles
and NOT the regular trash!
Introduction:
Diabetes mellitus is a metabolic disorder that appears to be related to defects in insulin
secretion and/or in defections in target cell responsiveness to insulin. Insulin is the
primary hormone in your body that promotes glucose uptake from the blood into the cells.
Insulin is released by the beta cells in the pancreatic islets. Without insulin, the blood
glucose concentration would greatly increase.
In 2012, 7.3% of Minnesotans had been diagnosed with diabetes (type 1 or 2)1. The
problem with this statistic is that many individuals are unaware that they have diabetes, so
the actual number of residents in the state might be much higher. Most diabetics in the
state are 65 years old or older, but the number of young people being diagnosed is on the
rise. This increase among youth appears to be linked with obesity and inactivity. Overall,
diabetes is associated with older adults, overweight and obese adults, some ethnic groups,
people with a family history of type 2 diabetes and individuals who are sedentary.
It is estimated that over 86 million people in the United States are pre-diabetic, where the
individual’s blood glucose concentration are higher then normal (fasting blood glucose of
70-100mg/dL), but not high enough for a diabetic diagnosis2. In Minnesota this value may
be as high as 35% of the adult population. There are three major forms of the disease:
Type 1, Type 2 and gestational diabetes.
The concentration of glucose in the blood is used to give an indication of blood glucose
control at the moment. Although, long-term control of blood glucose is evaluated using
glycated hemoglobin (HbA1c). The assay for glycated hemoglobin reflects blood glucose
control over the last three months because poor glycemic control (periods of
hyperglycemia) causing glucose to become inappropriately attached to hemoglobin
molecules.
Blood Glucose Concentrations for Diagnosis of Diabetes
Pre-prandial Blood
Postprandial Blood
Glucose Concentrations
Glucose Concentrations
Normal Values
< 100 mg/dL
< 140 mg/dL
Pre-diabetes
100 mg/dL – 126 mg/dL 140 mg/dL – 200 mg/dL
Diabetes
> 126 mg/dL
> 200 mg/dL*
Hypoglycemia
< 70 mg/dL
< 70 mg/dL
* random blood glucose measure
In this lab you will be following the case histories for three patients. You will be assessing
their blood sugar levels before and after a meal.
Patient 1 is a 21-year old woman that has experienced weight loss and is generally
concerned about her health. The woman has had no previous health problems,
although her family does have a history of diabetes although she is not sure of the
type of the disorder. She is a typical college senior.
Patient 2 is a 50-year old man complaining of a lack of energy. This patient is
overweight and does not exercise; his diet consists mostly of processes foods. His
family has a history of Type 2 diabetes.
Patient 3 is a 12-year old girl of average size. She complains of frequent urinations
and excessive thirst. She lacks energy and has experienced unexplained weight loss.
Her parents brought her in today because she is complaining of severe stomach
pain.
Exercise 8:
Based on the above descriptions, speculate on the pre-prandial and postprandial values for
each of the patients. These are your hypotheses. Fill in the appropriate statement areas on
your worksheet.
Students will work in groups of 4. One student will gather all of the necessary materials
and supplies to your table. These include: 2-3 paper towels, gloves for every group
member, (6) transfer pipettes, one glucose meter and 8 glucose meter test strips.
A second group member will collect the designated blood samples from the instructor. Pick
up pre-prandial and postprandial blood samples for each of the three patients from the
front desk. This means you should have a total of 6 blood samples to analyze.
In the meantime, label the transfer pipettes with the permanent marker so as not to mix up
the samples. Label 2 pipettes for each of the three patients.
Once all of the materials and supplies have been collected at your table, your group is ready
to start.
1.
Place a test strip into the glucose meter. Allow the meter to power up and recognize
that a test strip is in place. You should see a blood drop symbol in the meter’s display
indicating that the meter is waiting for a sample. (Make sure everyone in the group knows
how to work the meter. This may mean taking the test strip out and inserting it back into
the machine a couple of times.)
2.
Once the meter has powered up and is signifying it is ready, place a drop of preprandial blood from patient 1 on the designated test strip (that is in the glucose meter).
Immediately dispose of the transfer pipette into the biohazard bag at your table. Record
your results in the table on the worksheet. Then dispose of the “used” glucose test strip.
3.
Repeat this step for all of the other blood samples.
Record your results in the table on your worksheet. Then compare your results to the
blood glucose values in the above reference table and draw conclusions concerning the
blood glucose regulation of the three patients. Finally, address the thought questions on
your worksheet as a lab group.
References:
1.
Hollie E. Ables. 2014. Simulated diabetes testing experiment using artificially
manipulated livestock blood. Thesis for University of Mississippi in partial
fulfillment of the requirements of the Sally McDonnell Barksdale Honors College.
2.
Minnesota Department of Health. 2013.
http://www.health.state.mn.us/diabetes/pdf/DiabetesinMinnesota-2013-final-0317.pdf
2.
http://www.cdc.gov/diabetes/pubs/statsreport14/national-diabetes-reportweb.pdf
3.
http://histology.med.umich.edu/node/82 This is the Webscope link
Worksheet for Endocrine Laboratory
This worksheet is designed to help you progress through the lab exercise. Follow the
directions and complete the information.
Exercise 1, Part 1 and 2:
Use a highlighter and identify the pituitary and the
hypothalamus.
Fill in the name of the endocrine organs as indicated by the arrows on the torso diagram
below:
Some of the organs are deep to the other structures. The ones tinted in blue are deep to the
large and small intestine and liver. Also the male reproductive system is not shown.
Feel free to add any additional
organs that you see fit – this is
suppose to be a work in
progress.
Endocrine Hormone Chart: Much of this chart can be completed outside of class but the
content of this table should be understood for the laboratory exam.
Endocrine Organ
Hormone
Pineal Gland
Melatonin
Posterior Pituitary
Oxytocin
Posterior Pituitary
ADH
Anterior Pituitary
Growth
Hormone
Anterior Pituitary
Prolactin
Anterior Pituitary
LH
Anterior Pituitary
FSH
Anterior Pituitary
TSH
Anterior Pituitary
ACTH
Kidney
Erythropoietin
Heart
ANP
Liver
Angiotensin II
Thymus
Thymosins
Function of Hormone
Tropic
Hormone that
causes this
hormone to be
released.
Thyroid (follicular
Thyroid
cells)
Hormones
Thyroid (C cells)
Calcitonin
Parathyroid Gland
PTH
Pancreas
Insulin
Pancreas
Glucagon
Pancreas
Somatostatin
Adrenal Cortex
Aldosterone
Adrenal Cortex
Cortisol
Adrenal Cortex
Androgens
Adrenal Medulla
epinephrine
Ovary (granulosa
Estrogen
cells)
Ovary (corpus
Progesterone
luteum)
Testes
(sustentacular cells)
Inhibin
Testes (interstitial
Testosterone
cells)
For the following questions, work with your lab partner and adjacent study groups. Follow
along as you work through the laboratory exercises.
Exercise 1, Part 3:
1.
What role does the hypothalamus play in controlling the secretions of the pituitary
gland?
Exercise 2:
2.
Define portal system. Then speculate on the significance of such structures.
Draw your field of view of the pituitary gland as observed under the microscope. Off to
one side, explain in words how you would distinguish the anterior pituitary from the
posterior pituitary. Compare your answer with that of your lab partner.
Exercise 3:
Draw your field of view of the thyroid gland histology. Label the thyroid follicle with the
colloid inside and the follicular cells. Identify where the parafollicular cells (i.e., C cells)
should be located.
Exercise 4:
Draw the histology of the pancreas as seen in the microscope field of view. Label the
serous acini and the pancreatic islets. Compare your diagram to that of your lab partner,
then write how you will distinguish the cell types present.
Exercise 5:
In the space below, define cortex and medulla.
Draw the histology of the adrenal gland slide. Label the adrenal cortex and the adrenal
medulla. Then compare your diagram with your study partner and explain to each other
the function of the structures and how you will distinguish these structures on a lab
practical.
Exercise 6:
Draw the histology of the ovary slide. Then compare your diagram with your study
partner and explain to each other the function of the structures and how you will
distinguish these structures on a lab practical.
Draw what you see in the field of view for the testes slide. Label the seminiferous tubules,
germ cells and interstitial cells. Compare diagrams and discuss with your study partner
how you will distinguish these structures on a lab practical.
Physiology Section:
State your hypotheses about the three patients and their blood sugar values based on the
clinical information presented in the handout:
Patient 1:
Patient 2:
Patient 3:
Results:
Patient
Patient’s Glucose Concentrations
Pre-prandial
Postprandial
Diagnosis/conclusion*
blood glucose blood glucose
(review blood glucose table
(mg/dL)
(mg/dL)
above)
Patient 1
Patient 2
Patient 3
Compare your values to those of the reference table given in the introduction and write
your conclusions in the space provided in the table above.
Address the thought questions on your worksheet as a group. Then compare your answers
with those of another table.
a.
Are the pre-prandial and postprandial blood glucose levels different for the three
patients? Why?
b.
Why do doctors recommend exercise for their patients with Type 2 diabetes? Why
does exercise help those with the disease?
A hypothetical patient is a responsible diabetic who exercises regularly, eats
healthy, and takes her medications properly. The patient checks her blood glucose
concentration in the morning after she awakens and it is typically high. Address the
following question on your worksheet: Why is her blood glucose concentration
higher in the morning then at other times of the day?
c.
d.
A patient has been recently diagnosed with diabetes. This patient uses insulin
injections in order to control his diabetes. The patient has experienced a slight
weight gain since starting treatment. Address the following question on your
worksheet: What are some possible reasons for such a weight gain?
e.
A patient with diabetes becomes shaky and light-headed multiple times a week.
Address the following questions on your worksheet: What condition are these
symptoms characteristic of? What are some possible causes of the condition?