Name ______

Under Your Skin – 40 Informal Points

Introduction

The skin is the largest organ inthe human body; ifyou spread it out, it would cover about twenty square feet of surface area and weigh about ten pounds. You are constantly shedding skin cells and replacing them with new ones. About 35,000 dead, flattened skin cells are shed from the skin every minute. At this rate, a person is likely to shed over nine pounds of skin every year. These fallen flakes, together with other dust and particles, contribute to the dust in our homes. Microscopic dust mites could be, at this very moment,feeding on the skin cells you shed last night.

Our skin, along with our hair and nails, make up an important human body system called the integumentary system. Theintegumentary system, especially the skin, provides the body’s first line of defense. Skin functions to keep out invaders and protect the body from injury, but it also works to keep important materials inside the body.Liquid oozes from the pores to both protect and regulate. Tiny sensors in the skin help a person feel touch, temperature and, unfortunately, pain. The skin is a living, functioning organ that plays a key role in maintaining the body’s homeostasis. The skin protects the human body, but it also allows us to connect with the outside world.

Procedure

  1. Research and fill in the following table to describe each part of the skin.

Skin Structure / Description
Epidermis / The outermost layer of the skin that provides a waterproof barrier and creates skin tone (color)
Dermis / Layer beneath the epidermis that contains tough connective tissue, hair follicles and sweat glands.
Subcutaneous Layer (Fat Lobules) / Sometimes called the hypodermis. Made of fat and connective tissue. Fat provides cushioning and padding, reducing pain and protecting structures underneath.
Nerves / Peripheral nerves give feeling
Blood Vessels / Supply skin cells with oxygen and picking up carbon dioxide waste.
Sebaceous Gland / Secrete oily, waxy substances that waterproof and moisturize the skin.
Sweat Gland / Sweat is a mix of water and electrolytes. The evaporation of sweat from the skin produces a cooling effect.
Hair Follicle / The secretory cavity from which the root of a hair attaches and grows from.
Arrector pili muscle / Muscles that attach to hair follicles in mammals. Contraction of these muscles causes the hairs to stand on end, known as goosebumps.
Dermal papillae / The ridges on the skin. In fingers they create fingerprints and allow for friction and grip.
  1. In the space below draw a cross section diagram of skin. Include all of the parts listed in #1.

  1. Research the role of the following proteins in the skin and fill in the table.

Skin Protein / Description
Keratin / A protein in the epidermis that allows skin cells to adhere to each other, forming a protective layer on the outside of the skin.
Collagen / Gives skin its strength and structure.
Elastin / Keeps the skin elastic and flexible. Moisture keeps elastin healthy and long lasting. As this disintegrates with age wrinkles appear.
Melanin / Produces pigment in the skin. This is what is responsible for producing freckles or birth marks. It is also responsible for creating a tan when exposed to UV rays. It protects against UV rays, reducing the risk of skin cancer.
  1. Research 1st, 2nd, 3rd, and 4th degree burns. Describe, give an example of each, and provide treatment information.

Burn Level / Description / Example / Treatment
1st Degree / Affect only the top layer of skin. Not serious. / Touching a hot pan or hair straightening iron. / Cold pack, let heal on its own.
2nd Degree / Involve outer and inner layers of skin. Causes skin damage such as blistering and some scarring. / Hot liquid, chemical burn, electrical burn / Chemical and electrical burns must be checked out by a doctor, but most 2nd degree burns will heal on their own with time, although they are painful. Cold packs, creams and wrapping the area may help.
3rd Degree / Destroys the top two layers to skin. Causes skin to turn black, white, brown or yellow. Swelling. Lack of pain because nerves are killed off by the burn. / Scalding liquid, skin contacting a hot object for long period of time, flames from a fire / Heal slowly and poorly. Medical attention is a must. Skin grafting may occur depending on the size and location of the burn.
4th Degree / Destroys all skin and beyond, damaging or destroying tissues underneath the skin such as muscle, tendons, etc… / Fire, severe chemical or electrical burns / Medical intervention, hospitalization.
Treatment of skin, skin grafting as well as treatment for the damaged structures underneath the skin.