Wednesday, 6 June 2012

Critical Thinking/Making Connections

Making Connections Through "Reading"

After spending three school terms on researching the human skin, a basic connection can be made, and that is how the "function" of the skin plays a key role in determining our health. For my first term LiD project, I focused on the basic concepts of the skin (layers of skin and history of skin), and for the second term, I chose to do my research on common skin disorders and finally, my last term LiD project centers around skin pigmentation and how that determines the color of skin. All those three term projects share numerous connections between one another, and the most important one that I will point out is the fact that they all revolve around the idea of health issues and how that can affect us.


ž Shevick, Edward. "Chapter 9: Your Thin Skin." Health Science: Active Health Investigations (Science Action Labs). 31. Lorenz Corporation, 1998. Science Reference Center. Web. 21 Nov. 2011.
ž Rones, Nancy. "Stay safe in (and out of) the sun." Redbook 214.6 (2010): 75-82. Canadian Reference Centre. EBSCO. Web. 16 Oct. 2011.
ž Lynfield, Yelva Liptzin. "Skin." World Book Advanced. World Book, 2011. Web. 16 Oct. 2011.

  Multiple: Acne.UXL Encyclopedia of Diseases and Disorders. Rebecca J. Frey. Ed. Larry I. Lutwick. Vol. 1.  Detroit: UXL, 2009. p6-12. Word Count: 1659.
  Unknown: Eczema.UXL Encyclopedia of Diseases and Disorders. Rebecca J. Frey. Ed. Larry I. Lutwick. Vol. 2.  Detroit: UXL, 2009. p338-344. Word Count: 1454.
  "" MedicineNet. Web. 27 Feb. 2012. <>.
  Rockoff, Alan. "" MedicineNet. William C. Shiel Jr., MD, FACP, FACR. Web. 27 Feb. 2012. <>.
  "Common Menu Bar Links." ERROR. Web. 28 Feb. 2012. <>.

Albinism (Skin Pigmentation Disorder)

Skin Pigmentation Disorder: Albinism

Albinism is a skin pigmentation disorder that is caused by the absence of skin pigments. This results in pale or white skin as melanin, the determinant for skin color, is not present. Excessive absence of melanin results in visual problems and may lead to a higher potential diagnosis with skin cancers. (since individuals with albinism lack the dark pigment melanin, which protects the skin from ultraviolet radiation [sunlight])

  • This picture features an African boy with albinism. The lack of skin pigmentation resulted in the pale and white skin. 

Tuesday, 5 June 2012

Skin Color

Skin Pigmentation

Skin pigments are what determine the color of the skin. There are five major skin pigments, "melanin," "melanoid," "keratin," "hemoglobin," and "oxyhemoglobin." All of these skin pigments present at different levels in terms of the places where they are found in skin. While all these five skin pigments are important in determining the color of the skin, melanin remains the primary cause of skin color.

(Saharan African, Indian, Southern European, Northwest European)

  • The causes of the variation in skin is not certain, but it is arguable to be caused by genetics.
  • Skin color ranges from almost black to white due to blood vessels underneath

Key Terms and Ideas

Terminology for Human Skin

  • Epidermis- the first and the outermost layer of skin that makes contact with our surroundings. It consists of dead and dying cells
  • Dermis- the second and the middle layer of skin where new cells are born. It is supplied with blood vessels, nerves, hair roots and sweat glands
  • Hypodermis- the third and the innermost layer of human skin where larger blood vessels and clumps of fat-filled cells are found. It is where the muscles and the bones are attached by connective tissue
  • Skin Cell Gun- an airbrush-like tool that is used to isolate and spray stem cells onto severely burned skin in order to heal the wounds faster
  • Acne- a common skin disorder that often occurs during adolescence. It is caused by the blockage of hair follicles. {for more elaboration, please refer to [Common Skin Disorder (Acne)] }

Sunday, 3 June 2012

Common Skin Disorder (Eczema)


Eczema is a form of inflammation on the epidermis which does not have a direct cause to it. Doctors believe that it is caused by gene defects that lead to distortion of certain proteins which maintain the barrier of normal skin. The protection of skin is lowered which allows allergens and irritants to make contact with the sensitive skin. Eczema is also hereditary. Although eczema rarely causes death, according to the statistics of Canada, five Canadians died from eczema in 2008.

Cause: gene defects à distortion of proteins that maintain the barrier of skin à skin becomes sensitive à inflammation occurs à cracked and itchy skin

Common Skin Disorder (Skin Cancer)

Skin Cancer

Skin cancer is the most common form of human cancer. It is developed from the uncontrollable growth of cancer cells in the epidermis. Skin cancer is caused by the overexposure of ultra violet rays (sunlight, tanning booths) and basal cell carcinoma (BCC) is the most common type of skin cancer.

Common Skin Disorder (Acne)


a common skin disorder that often occurs during adolescence. It is caused by the overproduction of cells and sebum that combined to form a plug that blocks the hair follicles. Over time, the trapped sebum allows bacteria to grow in the follicle and eventually forms acne.

Process of the Production of Acne:

Excess cells+sebum (an oily substance secreted by  sebaceous glands)àformation of a plug àinfection with bacteriaà eruption of acne

In short, acne is caused by the blockage of hair follicles.

The Evolution of Human Skin

Past History

Our skin has not always been the same. Over the centuries, human skin has been gradually evolving in order to cope with the living environment. Paleontologists, people who study the history of life, have acknowledged the idea that human ancestors once possessed bodies covered in dense hair and rough skin. These two traits were important for human ancestors because they needed rough and hairy skin to protect them from the harsh winter, since the houses that they lived in back then were poor insulators against the bitter winter. As a result, the most obvious evolutionary adaptation is the roughness and the hairiness of skin.


Basic Concepts of the Human Skin

What is Human Skin?

Human skin is the largest organ that acts as the primary defense line against disease and injury. It protects the body from excessive water loss and receives information from the environment through nerves that respond to pressure, pain, heat or cold.

The Layers of Skin

        Human skin is composed of three distinct layers that function differently. They are "epidermis," "dermis," and "hypodermis (subcutaneous tissue)." 

A cross-section of human skin

    Epidermis- the topmost layer of skin that consists of mainly dead and dying cells. It is also the scientific term for the word "skin." 

    Dermis- the second and the middle layer of skin that is supplied with blood vessels, nerves, hair roots and sweat glands. It is where new cells are born.

    Hypodermis (aka. subcutaneous tissue)- the third and the innermost layer of human skin.Contains larger blood vessels, nerves and clumps of fat-filled cells that cushions the skin.