Integumentary System II

I. What determines skin color?
     A. Pigment (melanin-brown to black pigment)
     B. Blood circulating through skin
     C. Thickness of stratum corneum

II. Melanin is major contributor to skin color
     A. Produced by melanocytes in stratum basale
     B. Transfer melanin to e-cells in deep layers of epidermis
     C. Melanin is not evenly distributed, freckles, moles, genitalia have more
          1. all people have same number of melanocytes, just 
          produce more melanin

III. Melanin production is a result of genetics and exposure to light
     A. Albinism is a recessive gene causing absence of melanin
     B. Depth of melanin results in degree of color
          1. light reflecting off dark pigment scattered by collagen
          fibers shows as blue
          2. old tattoos and bruises

IV. Carotene-yellow pigment found in squash and carrots
     A. Stored in stratum corneum
     B. Can give skin a yellowish tint

V. Others
     A. lots of blood-blushing
     B. lack of blood-cyanosis
     C. birthmarks-congenital disorders of blood vessels in dermis

VI. Facts on hair
     A. hair is produced in hair bulb
     B. hair grows in growth/rest periods
          1. eyelashes 30 days (g), 105 ® 
          2. scalp 3 years (g), 1-2 ®
     C. male patterned baldness trait carried by women; male 
     hormone messes up hair follicles
     D. Errector Pili are muscles that raise and lower hair
          1. allows air to be trapped in between
          2. appear larger

VII. Glands (Two types)
     A. Sebaceous-produce sebum to lubricate
     B. Sweat
          1. merocrine-located everywhere (most # in palms/soles,  
          as temp goes up these are best places to lose heat
          2. apocrine- rich in organic substances; open in axillae 
          and genitalia; causes body odor

VIII. Nail-dead stratum corneum


End of Chapter Facts



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I. As age increases, elastic fibers loosen, “stretch” and wrinkles occur
     A. Sebaceous/sweat glands lack function, so you get colder
     B. Age Spots ( increased melanocytes not melanin)
     C. Gray hair from lack of melanin production

II.	Diagnostic tool
     A. skin can be hot, pale, contain lesions, rashes, etc.

III. Burns
     A. First degree- involves on epidermis heals in 1 week
     B. Second degree- involves on epidermis and dermis, 2 weeks 
     regeneration from e-tissue
     C. Third degree- recovery from would edge, they are white, tan, 
     brown, black, or deep cherry
          1. fluid loss
          2. e-tissue heals portions of second degree burn

*Be familiar with common skin maladies on page 106. 
Explain ringworm, acne, etc.*



This is a very cool site, that gives you lots of review on the 

Integumentary system. 

Click on the link at the top of the page: 


Extra links:
http://www.udel.edu/Biology/Wags/histopage/illuspage/iin/iin.htm