Module 1: Anatomy and Physiology of the Skin Flashcards
What is the deepest epithelial cell layer; that contains continuously dividing cell?
Stratum basale
- One-cell thick
- Only layer of the epidermis in which cells undergo mitosis
- Forms the dermal-epidermal junction (BMZ)
What is the name of the epithelial cell layer located between the stratum basale and stratum granulosum?
Stratum spinosum
- Consists of several rows of more mature keratinocytes, which appear spiny under a microscope
What is the epithelial cell layer located between the stratum spinosum and stratum lucidum?
Stratum granulosum
- Contains 3 to 5 flattened cell rows with increasing concentrations of keratin
What is the outermost epithelial cell layer; consists of dead keratinocytes?
Stratum corneum
- Consists of dead cells
- Sheds easily
- Contains keratin
- Functions as a barrier to the environment and prevents transepidermal water loss
- Enzymatic activity is involved in the formation of an acid mantle in the stratum corneum, which combine to make the skin less permeable to water and other polar solvents, and protect skin from microorganisms
- Low pH of the acid mantle enhances the skin barrier function
- Damage to the acid mantle, by repeated hand washing, for example, increases susceptibility to skin infections, eczema, contact dermatitis, atopic dermatitis, perineal dermatitis, and dry skin
- The pH of open wounds tends to be alkaline or neutral. As new epithelium is formed at the wound edges, the pH becomes similar to that of normal skin
- Skin cleaners and moisturizers that have low or neutral pH are recommended for maintaining the acid mantle of the skin
What epithelial cell layer is located between the stratum granulosum and stratum corneum?
Stratum lucidum
- Thin, clear layer of dead skin cells found in thick skin
What are the two main functions of the kerationcytes found in the epidermis?
- Reponsible for the toughness of the skin
- Produces keratin, the basic component of hair, skin, and nails
What is the main function of the melanocytes found in the epidermis?
- Responsible for producing melanin
What is the main function of the Langerhans’ cells found in the epidermis?
- Help protect the body against infection
What is the main function of the sebaceous glands (epidermal appendages)?
- Secrete sebum into hair follicles
What is the main function of the Merkel’s cells found in the epidermis?
- Mechanoreceptors that provide information on light touch sensation
What is the main function of hair follicles (epidermal appendages)?
- Hair contributes to:
- Appearance
- Body temperature
- Protection
- Sensation
What is the main function of the sebaceous glands (epidermal appendages)?
- Secrete sebum into hair follicles
What is the main function of the eccrine sweat glands (epidermal appendages)?
- Produce sweat to help regulate body temperature and assist with elimination of waste products
What is the main function of the apocrine sweat glands (epidermal appendages)?
- Produce sweat–responsible for “body odor”
What are nails (epidermal appendages)?
- Made of dead cells containing the protein keratin
What is the epidermal cell that resurfaces a wound and produces keratin?
Keratinocyte