SKIN AND THE INTEGUMENTARY  SYSTEM   

 

                   Juan Valverde de Amusco [anatomist] (ca. 1525 - ca. 1588)

                   A flayed cadaver holds his skin in one hand and a dissecting knife in the other.                     

                              Rome, 1559. Copperplate engraving. National Library of Medicine.  

                                    

I   Skin

            A.  Organ

            B.  Regions

                        1.  epidermis - epithelial tissue

                                    a.  general characteristics

                                    b.  layers

                                                1.  stratum germinativum (stratum basale)          

                                                2.  strateum corneum

                                    c.  cells

                                                1.  keratinocytes

                                                2.  melanocytes

                                                3.  Langerhans cells (macrophages)

                        2.  dermis - connective tissue

                                    a.  characteristics

                                    b.  regions

                                                1.  papillary

                                                            a.  dermal papillae

                                                            b.  Meissner's corpuscle (touch receptor)

                                                2.  reticular

                                                            a.  collagen and elastic fibers; lines of cleavage

                                                            b.  Pacinian corpuscles (touch receptor)

 

II   Hypodermis (subcutaneous, not skin)

           

III   Integumentary System

            A.  Definition

            B.  Associated structures (epidermal derivatives)

                        1.  hair

                                    a.  arrector pili (muscle)

                                    b.  root hair plexus (nerve)

                        2.  glands

                                    a.  sebaceous (oil)

                                    b.  sudoriferous (sweat)

                                                1.  eccrine

                                                2.  apocrine

                                    c.  ceruminous (wax)

            C.  Functions of integumentary system

 

IV  Skin cancer                                                                               

            A.  Basal cell carcinoma

            B.  Malignant melanoma   (ABCDE  rule) * 

 

    * Diagnostic criteria for malignant melanoma:

   

   A
 
asymmetry
The mole or lesion is asymmetric which means no matter where you mirror the lesion it will not be equal.
 
 
   B
 
borders
The mole or lesion has irregular borders.
  
 
   C
 
colors
The mole or lesion is irregularly colored ranging from light brown to dark brown, black, red, blue or white

 
   D
 
diameter
A mole or lesion is suspicious if it is over 5 mm in diameter.

 
   E
 
elevation
The elevation of a mole or lesion may be a hint for the lesion being malignant.
 
 

 

                       

IV   Epithelial Membranes

            A.  Definition

            B.  Types

                        1.  cutaneous (skin)

                        2.  mucosa (cavities open to exterior)

                        3.  serosa (closed body cavities)

                                    a.  parietal (lines cavity)

                                    b.  visceral (covers organ)

 

 

 

At the end of this unit you should be able to do the following:

    -  define skin, hypodermis, and integumentary system

    -  compare the general characteristics of the epidermis and dermis

    -  identify the different layers and different cell types of the epidermis in a diagram

    -  compare the stratum germinativum and the stratum corneum structurally and functionally

    -  compare the location and function of keratinocytes, melanocytes, and Langerhans cells

    -  identify and describe the different layers and different cell types of the dermis in a diagram

    -  draw a hair, its sebaceous gland, arrector pili and root hair plexus and discuss the function of each

    -  list the three types of glands found in the skin and the secretion of each type

    -  compare and contrast the location, secretion and function of eccrine and apocrine sudoriferous glands

    -  discuss the functions of the skin

    -  identify the characteristics of malignant melanoma (ABCDE rule)

    -  list the three types of epithelial membranes and compare their structure and location

 

 

 

                 

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