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
What is the protein produced by keratinocytes?
Keratin
- A protein produced by keratinocytes
- Nails are made of hard keratin
- Hair is made of soft keratin
What do you call a localized buildup of stratum corneum cells due to pressure or friction?
Callus
What are the pigment producing cells within the epidermis called?
Melanocytes
What is the dark pigment of the skin and hair, formed by melanocytes called?
Melanin
What epidermal appendages are located within the dermis and are made of soft keratin?
Hair
What epidermal appendage secretes oil and is located within the dermis?
Sebaceous gland
What oily substance lubricates the skin and hair?
Sebum
What is another name for sweat glands that are epidermal appendages within the dermis?
Sudoriferous glands
What epidermal appendage is made of hard keratin and located at the dorsal tips of the digits?
Nails
What is the superficial dermal layer called that consists of loosely arranged connective tissue?
Papillary dermis
What is the thick, deep dermal layer consisting of dense, irregularly arranged connective tissue called?
Reticular dermis
What is the collection of fluid at the junction between the dermis and epidermis due to friction called?
Blister
What is the dermal cell called that produces collagen, elastin, granulation tissue, and growth factors?
Fibroblast
What is the main supportive protein of the skin?
Collagen
What protein is found in connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting?
Elastin
What cell directs the repair process, secretes growth factors and enzymes, and destroys bacteria and debris?
Macrophage
What cells help fight infection?
White blood cell
What cell helps initiate inflammation through secretion of histamine, enzymes, and chemical mediators?
Mast cell
What is the name of the chemical mediator released by mast cells which causes vasodilation, increased vessel wall permeability, and attracts other cells to the area?
Histamine
What is the process of engulfing and destroying bacteria and/or debris called?
Phagocytizing
What is the name of the tissue that contains vascular, loose connective tissue that stores fat and provides energy, cushioning and insulation?
Adipose tissue
What is the fibrous connective tissue called that separates and surrounds structures and facititates movement between adjacent structures?
Fasica
What is a wound called that involves only the epidermis?
Superficial wound
What is a wound called that involves the epidermis and part of the dermis?
Partial-thickness wound
What is a wound called that extends through the epidermis and dermis and into or through the subcutaneous tissue?
Full-thickness wound
What is the fibrous cord of connective tissue continuous with the fibers of a muscle and attaching the muscle to bone or cartilage called?
Tendon
