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Integumentary System - Hair, Glands, Nails, Injury Repair, Skin Cancer, and Burns

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Terms in this set (25)

  • What is hair and where does it originate?

    Hair is a nonliving accessory structure produced in a hair follicle. It originates in the dermis and projects through the epidermis.

  • What are the two main regions of hair?

    Hair root anchors into the skin and extends halfway to the surface. Hair shaft extends from the root and forms the visible portion.

  • Name the three layers of hair structure.

    Medulla (central core), cortex (intermediate layer), and cuticle (surface layer).

  • What are the three layers of hair follicles?

    Internal root sheath, external root sheath, and glassy membrane wrapped in connective tissue sheath.

  • How do hair follicle shapes affect hair type?

    Oval follicles produce curly hair; round follicles produce straight hair.

  • Where does hair production begin and what cells produce hair?

    Hair production begins at the hair bulb surrounding the hair papilla. Basal cells in the hair matrix produce hair cells.

  • What are the two types of hair and their characteristics?

    Vellus hairs are soft, fine, and cover most of the body. Terminal hairs are heavy, pigmented, found on head, eyebrows, and eyelashes.

  • What determines hair color?

    Hair color depends on pigment production by melanocytes at the hair matrix, influenced by genes, environment, and age.

  • Describe the hair growth cycle.

    Hair grows as root cells absorb nutrients. At cycle end, follicle becomes inactive and hair is called club hair. New growth cycles produce new hair and shed club hair.

  • What are sebaceous glands and their function?

    Sebaceous glands are holocrine glands producing oily sebum into hair follicles to lubricate and protect hair shafts.

  • Where are sebaceous follicles found and what do they do?

    Large sebaceous glands discharging sebum directly onto skin surface, found on face, back, chest, nipples, and external genitalia.

  • What are apocrine sweat glands and where are they located?

    Apocrine sweat glands secrete sweat into hair follicles, found in armpits, around nipples, and pubic region, starting secretion at puberty.

  • What controls secretion of apocrine and sebaceous glands?

    The autonomic nervous system (ANS) controls sebaceous and apocrine sweat glands, causing involuntary secretion.

  • What are eccrine sweat glands and their functions?

    Eccrine sweat glands secrete sweat directly onto skin surface for evaporative cooling, excreting water and electrolytes, and protection from hazards.

  • Name two other specialized skin glands and their functions.

    Mammary glands produce milk; ceruminous glands produce earwax to prevent foreign particles from reaching the eardrum.

  • What are nails and their main parts?

    Nails are dead, keratinized epidermal cells protecting finger and toe tips. Main parts: nail body, nail root, eponychium (cuticle), lunula, and hyponychium.

  • What are the four phases of skin injury repair?

    Inflammatory phase, migration phase, proliferation phase, and scarring phase.

  • What happens during the inflammatory phase of injury repair?

    Bleeding, swelling, and pain occur. Mast cells trigger inflammation.

  • Describe the migration phase of injury repair.

    A scab forms; macrophages clean debris; epidermal cells migrate to repair epidermis; fibroblasts and endothelial cells repair dermis and blood supply.

  • What characterizes the proliferation phase of injury repair?

    Scab disintegrates; fibroblasts produce collagen meshwork; epidermal cells migrate over collagen to restore skin.

  • What occurs during the scarring phase of injury repair?

    Scar tissue forms, which is less flexible, has more fibers, and fewer blood vessels than normal tissue.

  • What are the three main types of skin cancer?

    Basal cell carcinoma (from stratum basale), squamous cell carcinoma (from epidermal squamous cells), and melanoma (from melanocytes).

  • Which skin cancer type commonly metastasizes?

    Melanoma commonly metastasizes; basal and squamous cell carcinomas usually do not.

  • Describe the three degrees of burns.

    First degree: damages epidermis only; second degree: damages epidermis and part of dermis; third degree: destroys epidermis, dermis, and extends to subcutaneous layer.

  • What is the role of Epidermal Growth Factor (EGF) in skin repair?

    EGF promotes basal cell division, keratin production, epidermal development, repair, and gland secretion; used in labs to grow skin grafts.