LAB REPORT #5: INTEGUMENTARY SYSTEM

Biology I, Pre-Health Sciences – Durham College, Fall 2020

/40 marks

EVALUATION NOTES

Read before submitting:

 The lab report is worth 5% of your final grade.

 This lab report is due by 11:59 pm on the due date established by your instructor.

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grade of 0 is assigned.

 This lab report should be submitted online to the DC Connect Assignments folder.

a. The report should be submitted to DC Connect. Unless otherwise directed,

submissions made by other means (E.g. email or hard copy) will not be
accepted and will result in a grade of 0.

b. Computer malfunctions or technical issues are not accepted as excuses for late
or missing reports. TIP: Submit your report early so that you have time to
resolve any potential technical issues prior to the deadline.

 While students may work in groups to complete labs, each student must submit their own
original work.
PART 1 – YEP, THAT’S A BURN

Introduction
Skin cancer is one of the most common cancers in young people. It is also one of the easiest
cancers to prevent. In this section, you will investigate the effectiveness of common types of
UV protection by examining UV test strips that have been exposed to UV light under various
conditions. Specifically, the following questions will be asked:

• Does the level of sun protection factor (SPF) in sunscreen

matter?
o To test this, you will examine UV test strips that have
had 3 types of SPF (SPF 15, SPF 30, and SPF 50)
applied.

• Does the composition of sunscreen matter?

o To test this, you will examine UV test strips that have
had a mineral-based sunscreen, a chemical-based
sunscreen, and tanning oil applied.

• Does our clothing provide any protection against sun?

o To test this, you will examine UV test strips that have [Source]
been covered by 3 types of fabric (cotton, polyester,
and jean).

• How do common activities (sitting outdoors in the shade,

driving in our car by a window, swimming in a pool) affect our
sun exposure?
o To test this, you will examine UV test strips that have
been covered by various materials (leaf, glass, and
water).

Procedure

1. To carry out these experiments, the following procedure was performed for you:

a. UV test strips were obtained

b. The “UV protection items” were placed over the UV test strips.
c. The UV test strips were exposed to UV light for 3 minutes by holding a UV
flashlight 2 cm above the strips.
d. The test strips were collected for further analysis
2. A summary of the results is provided in the following Tables. *NOTE: The “control” is a
test strip that has not been covered by any “UV protection item,” i.e. it is fully
exposed to the light from the UV flashlight.

Sunscreen SPF Chemical Chemical Chemical

Control
-SPF 15 -SPF 30 -SPF 50
Sunscreen Mineral Chemical
composition Control Tanning oil
-SPF 30 -SPF 30
Clothing Control Blue cotton Blue polyester Blue jean
Natural materials Control Leaf Glass Water

Sunscreen SPF

Sunscreen
composition
Clothing

Natural materials

3. (4 marks) Use the scale below to assign a UV protection level to each strip. Record
your analyses in the table below. NOTES: (a) Use decimals (E.g. 1.5) if the protection
level is somewhere in the middle. (b) This task is somewhat subjective; if you are
relatively close you will be marked correct. (c) Some have been completed for you.
Protection Colour
0 Dark blue green
1 Dark green with some lighter spots
2 Light green
3 Light green with some yellow
4 Yellow with some green
5 Full yellow

Sunscreen SPF
1 4.5 5 5
Sunscreen
1 4 5 1.5
composition
Clothing
.5 3.5 4 5
Natural materials
1 4.5 1 1.5
4. CASE STUDY: You have been tasked with babysitting your 1-year-old nephew,
James, and have decided to take him to the park on a hot, sunny day. At the
insistence of his father, you have promised to ensure James is protected from the sun
at all times. Luckily, you remember learning about sun protection within the Pre-
Health Sciences program at Durham College and are confident in your ability to
prevent sun exposure.

a. (4 marks) Using your results, reassure James’s father by describing FOUR specific
ways in which you will prevent James from getting a sunburn. Your answers must
be supported by the data collected.

Recommendation Supporting evidence from the data

He will be wearing a blue Blue polyester scored higher than cotton on

polyester shirt, with blue the UV protection score strips.
jeans Blue jeans had a full yellow result, making it
the perfect material to wear for protection.
Using and frequently Chemical sunscreen had shown more UV
applying chemical protection than mineral sunscreen with a 4.5
sunscreen over mineral score on the UV protection scoring test.

Using SPF 30 or higher SPF 30 and SPF 50 had received the same
score on the UV protection stripe tests with a
full yellow result. So using SPF 30 or higher is
recommended.
Eat snacks and park under a A leaf on the UV protection level strip had
tree with many leaves shown a score of 4.5, therefore offering almost
a perfect protection score

b. James’s father is insisting that you purchase SPF 50 sunscreen as opposed to the
SPF 30 that you were planning on using.

I. (2 marks) Is SPF 30 is a poor choice for sunscreen? Explain using evidence

from your data. Be as specific as possible.

YES or NO (highlight)

Evidence from your data: No, SPF 30 is not a poor choice compared to SPF 50
as there is little to no difference in protection; based on the UV protection stripe
test as well as the graph indicating the level of SPF and the amount of
protection.
 II. (1 mark) Using the graph to the right as
an aid, indicate if the following statement
is TRUE or FALSE: “A sunscreen that is
SPF 30 has twice as much protection as a
sunscreen that is SPF 15.”

TRUE or FALSE (highlight)

PART 2 – SKIN CANCER

Introduction
According to the Canadian Cancer Society, people who have had at least one blistering
sunburn as a child or teenager have a higher risk of developing melanoma later in life. In
fact, the more sunburns you have had, the greater the risk of melanoma. Luckily, when
melanoma is found and treated early, the chances of a successful recovery are high. For
this reason, medical professionals recommend checking your skin regularly for potential
changes. This will help you get to know what is normal for your skin and notice if something
looks wrong.

Procedure

5. Read the list of criteria, termed ABCDE, for determining if something should be
examined by a doctor to see if it is cancerous:
 [Source]

6. (5 marks) Examine the moles in Image A and Image B below. Use the ABCDE
guidelines to determine if the mole image warrants further examination by a doctor.
Provide 2 reasons for your decision.

Y/N – Should
Justify your answer - List 2 reasons for
Image a doctor
your decision using ABCDE guidelines.
examine?

Yes - This mole has an

irregular boarder and
is asymmetrical in
shape.

- The diameter is
7mm in diameter
A which is greater than
the recommended
6mm size.
Diameter = 7 mm
[Source]

No - This lesion is
consistent in colour,
and has a smooth
boarder

- The diameter is
under 6mm and is
relatively
symmetrical in
shape. I
B
- If this lesion changes
in any way, its
Diameter = 5 mm recommended to see
[Source] a doctor to be sure
as evolution is
possible.

-
 7. CASE STUDY (continued): After visiting the park with James, you drop him off back at
home. James’s father immediately notices a “major sunburn” on the top of James’s
ear (a place where you forgot to put sunscreen) and a small mole on James’s shoulder
that “for sure wasn’t there before.” You examine the mole further. It looks completely
circular, is 1 mm in diameter, and is solid brown.

a. (1 mark) Multiple choice - If the burn on James’s ear ends up peeling but not
blistering, what type of burn is it? Highlight your answer.
i. Superficial
ii. Partial thickness
iii. Full thickness

b. (2 marks) Based on information above, would you recommend that a doctor inspect
the mole further? Explain why you think this using ABCDE guidelines.

Recommendation: No
Reasons based on ABCDE guidelines: If the mole is perfectly circle, is under 6mm
in size, and is consistent in colour, there shouldn’t be any reason to have the mole
checked out by a doctor. If the mole changes in size, shape, colour, texture; then its
recommended to see a doctor as evolution and changes in a mole is in the ABCDE
guidelines.

PART 3 – SKIN MICROSCOPY & MODELING

Introduction
In this section you will explore the anatomy of the integumentary system by examining
specific skin layers under the microscope. Be sure to use this portion of the lab to solidify
your understanding of skin anatomy.

Procedure
8. Visit the histology website below and explore the various layers of skin under the
microscope. Use the + , - ,  and  buttons to move around the slide and zoom in
and out. Click the links in the description of “thick skin” on the right-hand side to locate
the various layers.
http://www.histologyguide.com/slideview/MH-091-thick-skin/11-slide-1.html?
x=23423&y=19693&z=9.9&page=1

9. Using the website above, complete the following tasks:

a. (3 marks) Submit a screenshot of the epidermis, dermis, and hypodermis
layers. Insert these images into the chart below.
Epidermis Dermis Hypodermis

b. (1.5 marks) Indicate what major cell types are found within the epidermis, dermis
and hypodermis by matching the labels A-C in the image to the cell types below:

___C_ adipocyte

___B_ fibroblast

__A keratinocyte
c. Examine the image below:

i. (2.5 marks) Provide names for labels A-E representing the 5 layers of the
epidermis.

A = stratum corneum
B = stratum lucidum
C = stratum granulosum
D = stratum spinosum
E = stratum basale

ii. (2 marks) Indicate which letter A-E best describes the following:

Most rapidly dividing cells in the body = E

Waterproof layer = A
Most superficial layer = A
Thickest layer of keratinocytes = A
 d. (10 marks) Match the descriptions below with their correct term. Answers are used
only once. [Hint: refer to your online notes if you get stuck.]

A. Adipocyte K. Papillary layer

B. Arrector pili L. Reticular layer
C. Dermis M. Sebaceous gland
D. Epidermis N. Sebum
E. Fibroblast O. Stratum basale
F. Hypodermis P. Stratum corneum
G. Keratinocyte Q. Stratum granulosum
H. Langerhans cell R. Stratum lucidem
I. Melanocyte S. Stratum spinosum
J. Merkel cell T. Sudoriferous gland

____A__ Cell that stores fat

___K___ The layer of dermis that contains a high number of blood vessels
____T__ Can be eccrine or apocrine
___H___ Immune cell within the epidermis
___N___ Causes acne when overproduced in the presence of bacteria
____D__ A main region that contains 5 layers of keratinocytes and is avascular
____B__ Structure that attaches the hair follicle to the top of the papillary layer
____E__ Most common type of cell within the dermis
M Gland that produces oil
____O__ The layer of epidermis that contains Merkel cells

10. (2 marks) Below is a slide of melanoma under the microscope.

e. Indicate the following:

i. What skin pigment is produced by melanocytes?
__melanin___
ii. What layer of the skin are melanocytes typically found in?
Be as specific as possible. _basal layer in the epidermis
f. Indicate whether the statements are TRUE or FALSE:
i. As a person ages, melanocytes decrease in number and
increase in size.
ii. ___True____ Melanoma is less dangerous than squamous cell carcinoma