Flashcards in Dermatopathology Deck (102)
Functions of the Skin
Prevent fluid loss
Area for heat exchange
Protects against invading microorganisms
Neurological receptor relay system: touch, pressure, temp, pain
Vitamin D synthesis
Four Types of Skin Cells
What is the predominant cell of the epidermis?
What happens to the keratinocytes as they move superficially?
What is keratin essential for?
Protective function of the skin
Is the structure protein of hair & nails
Five Layers of Keratinocytes
Stratum germinativum OR stratum basale
Define Stratum Germinativum or Stratum Basale
Single layer of columnar cells, undergo mitosis, no migration
Define Stratum Spinosum
Two to four layers, cells differentiate
Define Stratum Granulosum
Only a few layers, most differentiated
Define Stratum Lucidum
Thin, transparent, layer mostly confined to the palms of the hand & soles of feet, transitional cells
Define Stratum Corneum
Many layers, dead squamous-type keratinized cells
Where are melanocytes located?
At or in the basal layer
What is the primary function of melanocytes?
Protect from UV rays
What do merkel cells function as?
Mechanoreceptors: touch receptors
Where are Langerhans' cells located?
Scattered in the supra basal layer of the epidermis
What are Langerhans' cells responsible for?
Recognizing foreign antigens harmful to the body
Connective tissue layer separating the epidermis from the subcutaneous fat layer
What is the dermis mostly composed of?
Variety of immune cells
What does the subcutaneous tissue consist of?
Primarily fat & connective tissues that lend support to the vascular & neural structures supplying the dermis & epidermis
Examples of Skin Appendages
2 Types of Sweat Glands
Location of Eccrine/Merocrine Sweat Glands
Entire body surface
Originate in dermis & open directly to the skin surface
Primary Function of Eccrine/Merocrine Sweat Glands
Transport sweat to body surface to regulate body temperature
Location of Apocrine Sweat Glands
Deep dermal layer
Characteristics of Apocrine Sweat Glands
Open through hair follicle
Secrete an oily substance
Where are sebaceous glands located?
Over entire skin surface except for the palms, soles, and side of feet
What do sebaceous glands secrete?
Sebum: lipids, cholesterol, & other substances
Function of Sebaceous Glands
Lubricate hair & skin
What does the hair structure consist of?
Hair follicle & hair shaft
Hair muscle (arrector pili muscle)
Apocrine gland (sometimes)