See.: Name: _

iExperiment: Structures and Functions of the Skin(B. Science 10-36-3b)

Purpose: To learn some the structures and!functions of the skin.I,

Materials: Dissecting microscope your handpolygraph for lie detector

Methods:1. Observe the skin of your hand under thedissecting microscope, then draw observations.2. A lie detector uses the principle that during

_ -.;:: n_ ._. • n. ~ stressful times (like lying), that people .·sweatV) . -ttirolJgh their skin. This sweat contains salt that changes the resistance on the skin.::s This change is recorded on the polygraph. Record a section of the polygraph in

~ results. Label what caused the peaks observed.3. Label the diagram in results with the words printed in bold.

The skin is made of three layers; the epidermis, dermis and subcutaneoustissue or hypodermis (the fatty layer). The epidermis is the outer portion of yourskin. It is made up of many epithelial cells. The outer layer forms the horny layer.These outer cells are flattened, dead, and scale like. The germinative layer is theinner layer which is larger and more active. Active cells in the lower layers replaceepidermal cells as fast as they are lost. Friction and pressure on the epidermisstimulate cell division. This may produce a thickening of more than a hundred cells.The thickening of the epidermis is called a callus.

A sweat gland is shaped like a tiny tube. It's main portion is in the fattytissue of the skin and the duct of the sweat gland goes through the dermis I~yerand opens right out on the surface of the skin (epidermis layer), this opening is calledthe pore of sweat gland ..Observe the diagram of the hair roots and label the parts printed in bold. The deepestpart of the hair root is down next to the fatty layer of the skin. The shaft of ~hehair reaches from this deepest part through a tunnel in the dermis and epidermis tothe outside. There are tiny muscles in the dermis of the skin. Each of these fastens toone end near the deepest part of the hair root. The other end fastens near the dividingline between the dermis and epidermis. Sometimes these tiny muscles tighten up .Because the muscles fasten near the epidermis, they cause small dimples and bumpsto form in the skin and cause hair to stand straight out.

The hypodermis (or subcutaneous) layer consists primarily of fat which actsas a storage for energy molecules and protects against the cold. Throughout the fatare nerve and blood vessels.

Results: 1. Your hand.

-Foster! You bcttiM' grt Q'VeI" hac ~ you want to s«

tvt«hcT's tunplo.aiJ m.aU'ificd 500 times."

Small portion of polygraph.

See.: Name: _3.

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capillaries

oil gland

nerve ending(pressurereceptor)

Conclusions:

1. Identify the parts of the integumentary system that carry out each function listedbelow (Be specific, don't just put skin).

a. Protect against infection and injury:b. Regulate body temperature:c. Removes waste products:d. Protects from ultraviolet radiation:

e. Allows for sensory information:2. Explain the principle behind how the lie detector works.

Discussion:

1. Describe how hairs may stand straight out from your skin.

2. Why is it important to bath regularly?

3. Discuss why the lie detector may show inaccurate results.

4. Read Matthew 5: 27 - 30. If your skin or any other part of your body makes youstumble, what should you as a Christian do? (Understand the symbolic meaning oftext. )

Sa. So much money is spent in our society trying to make our skin and outwardappearance look good. Read I Sam 16:7, Mat 23:27-28 and comment on what shouldbe our emphasis in our appearance

5b. Read I Peter 3:3-4. Be specific as you comment on what is "precious in the sight ofGod"?