1. Homeostasis and Functions
Integumentary
Homeostasis and Functions

2. State Standard
7) Explain how organisms use positive and negative feedback mechanisms to maintain their internal environment and respond to external environmental changes. Identify possible consequences that can occur if the body does not maintain homeostasis. Summarize how cellular metabolism can affect the body’s homeostatic state.
8) Create a model with a written, digital, or verbal explanation of the three layers of skin (epidermis, dermis, and subcutaneous). Summarize functions and characteristics of each layer; describe layers within epidermis and dermis; outline and sketch cell types and definitions, appendages, blood supply, innervation, and possible lesions. .

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Objectives
Students will be able to…
Describe how the integumentary system works to maintain homeostasis through a skin lab activity
Describe the functions of the integumentary system through a skin lab activity.
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4. Homeostasis and the skin
Skin: complex with crucial roles in homeostasis
Protects underlying tissue from injury
Aids in temperature regulation
Prevents excessive water loss
Acts as sense organ
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FUNCTIONS OF THE SKIN
The skin has 7 functions:
Covers underlying tissues to protect against dehydration, injury, and germ invasion
Regulates body temperature
Helps manufacture vitamin D
Serves as the site of many nerve endings
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FUNCTIONS OF THE SKIN
Temporarily stores fat, glucose, water, and salts
Screens out ultraviolet radiation
Absorbs certain drugs and chemical substances
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Discussion
Applying what you have just learned about the functions of the skin and its role in homeostasis, is the skin an organ? Why or why not?
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Pigmentation
Basic skin color is inherited and is determined by melanin (Brownish/black pigment) in the outer layer of the skin
Everyone has the same number of melanin producing cells but the genetics of certain racial groups determine the amount of melanin produced
Melanin is present to protect us from ultraviolet light
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Pigmentation
A person who has an absence of melanin is an considered an Albino
An Albino’s skin has a pinkish tint and the hair is pale yellow or white
The eyes also lack pigment and appear red.
They are very sensitive to light
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Albino
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11. Abnormal Pigmentation
Abnormal pigmentation can indicate disease or a problem with homeostasis
Erythema- reddish color of the skin caused by burns, congestion of blood in vessels, or temperature change.
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13. Abnormal pigmentation
Jaundice-a yellow discoloration of the skin
Indicates bile in the blood as a result of liver or gallbladder or red blood cell destruction
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Discussion questions
In a small group discuss
Why are we all different skin tones?
Why would skin condition be part of a health care workers patient assessment?
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16. Activity We will be breaking into groups and doing lab stations.
Read the First 2 pages of the skin lab activity stations sheet
Station 1: Inflammatory response
Station 2: Temperature
Station 3: Hair Skin and nails
Station 4: Protective Oils
Complete the questions at each station
Individually: Write a summary of what you learned about the functions of the integumentary system in your lab activity. How does the skin function to maintain homeostasis? Give an example from your lab activity.

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Integumentary
Structure of the Skin
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State Standard
8) Create a model with a written, digital, or verbal explanation of the three layers of skin (epidermis, dermis, and subcutaneous). Summarize functions and characteristics of each layer; describe layers within epidermis and dermis; outline and sketch cell types and definitions, appendages, blood supply, innervation, and possible lesions.
©2004 Delmar Learning, a Division of Thomson Learning, Inc.

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Objectives
Students will be able to..
Identify the functions and structures of the layers of the skin through creation of a model.
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Structure of the Skin
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STRUCTURE OF THE SKIN
Layers of the skin:
Epidermis - the outermost covering of epithelial cells with no blood vessels or nerves
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1st layer -Epidermis
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2nd Layer Dermis
Dermis – “true skin” made of connective tissue and is vascular
Contains blood vessels, nerves, muscle, sweat and oil glands, and hair follicles
Creates ridges known as fingerprints
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3rd Layer Subcutaneous
Subcutaneous
lies under the dermis and consists of loose connective tissue, and fat.
Connects the skin to the underlying muscles
Contains hair follicles and small muscles called erector pili that tighten when you are cold (goosebumps)
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STRUCTURE OF THE SKIN
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Discussion Questions
Take a moment and discuss in a small group 1. If you take a sterile needle and pass it through the outermost layer of the skin, no bleeding or pain occurs. Why is this possible?
When you get a paper cut why does it hurt? What layers are effected?
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29. Activity Create a model of the skin with the provided materials
Label all structures of the skin
Label the different layers
Color the layers and structures
On the back write the purpose of the skin, what each skin layer contains and 2 interesting facts about the skin
Individually complete the review questions on p.79 and the applying theory questions on p.80

30. Appendages of the Skin Skin Eruptions and Cancer
Integumentary
Appendages of the Skin Skin Eruptions and Cancer
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State Standard
9) Investigate and obtain information on a skin disorder/disease/syndrome from a medical/healthcare journal or textbook. Appraise a sample case study involving review of the A&P of the cells and tissues affected. Decide whether an inflammatory response was involved, identify the causative agent, locate signs and symptoms of the disorder, and relate to normal A&P.
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Objectives
Students will be able to…
Identify common skin disorders.
Investigate issues with normal anatomy, cellular/tissue changes, causative agent, signs and symptoms in a case study activity.
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APPENDAGES OF THE SKIN
Hair
Protects the body, and covers all surfaces except palms and soles of feet
Nails
Protect the fingers and toes
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34. Glands of the skin Sebaceous Glands Sweat Glands
Oil glands open onto hair follicles moisturizes the skin and hair
Sweat Glands
Coiled tubes that extend through the dermis and open on the surface of the skin at pores. Releases perspiration removing excess water and cools the body through evaporation

35. THE INTEGUMENT AND ITS RELATIONSHIP TO MICROORGANISMS
The Skin protects from bacteria entering the body.
Most skin bacteria are associated with hair follicles or sweat glands where nutrients and moisture are present
The best way to prevent disease is good hygiene and washing the hands

36. Acne Vulgaris Common Chronic disorder of the sebaceous glands
Due to excess production of oil
Plugs the opening to the gland preventing outflow of oil
White blood cells attack creating pus and an inflammatory response.
Can lead to cellulitis (an infection of the subcutaneous layer of the skin)

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Acne and Acne scarring
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Discussion
Applying what you know about the skin and infection control, explain a scenario that could result in a cellulitis infection.
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39. Eczema Noncontagious acute inflammatory skin disease
Dry red itchy scaly appearance to the skin
Mainly due to an underlying allergic reaction
Avoidance of the cause typically cures

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Eczema
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Psoriasis
Chronic inflammatory skin disease
Dry reddish patches covered with silvery white scales.
Typically seen on elbows, knees, scalp and back
Treated using immune system suppressing drugs.
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Psoriasis
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Discussion
In order to treat psoriasis, the patient must take drugs that suppress the immune system. What impact will this have on homeostasis in the body?
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Boils
Painful bacterial infection of the hair follicles or sebaceous glands
Typically due to a staph infection.
Deep in the skin and often require drainage, excision, and antibiotics
**Warning Yucky picture ahead**
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45. Boil

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Skin Cancers
Typically due to exposure to ultraviolet light
3 main types
Basal cell carcinoma- most common and least dangerous
Squamous cell carcinoma-grows rapidly and spreads
Malignant melanoma-happens in the pigmented cells of the skin, spreads quickly, typically brown or black
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47. Discussion
How can you use the information that you learn about skin cancer in your everyday life?
Who in your family might you need to check and why?

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Activity
Complete the Skin Cancer Case Study and Research Activity located under the ppt. on the class website.
Read the Case Study and answer the questions.
You may have to research some of your answers.
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