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Integumentary System - Anatomy & Physiology

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Terms in this set (28)

  • What are the main components of the integumentary system?

    The integumentary system consists of skin, hair, nails, sweat glands, and sebaceous (oil) glands.

  • What are the three main layers of the skin?

    The skin has three layers: epidermis (superficial, epithelial, avascular), dermis (underlying, fibrous connective tissue, vascular), and hypodermis (subcutaneous layer, mostly adipose tissue, not part of skin).

  • What type of tissue composes the epidermis?

    The epidermis is composed mostly of keratinized stratified squamous epithelium.

  • Name the four main cell types found in the epidermis.

    1. Keratinocytes (produce keratin)
    2. Melanocytes (produce melanin)
    3. Dendritic (Langerhans) cells (immune cells)
    4. Tactile (Merkel) cells (touch receptors)

  • List the five layers (strata) of the epidermis in thick skin.

    1. Stratum basale
    2. Stratum spinosum
    3. Stratum granulosum
    4. Stratum lucidum (only in thick skin)
    5. Stratum corneum

  • What is the function of the stratum basale?

    The stratum basale is the deepest epidermal layer with actively dividing stem cells producing new keratinocytes; it also contains melanocytes.

  • Describe the stratum spinosum.

    Several layers thick with keratinocytes connected by desmosomes; cells appear spiky and contain melanosomes and dendritic cells.

  • What happens in the stratum granulosum?

    Cells flatten, nuclei and organelles disintegrate, keratinization begins, and cells accumulate keratohyaline and lamellar granules to form a water-resistant barrier.

  • Where is the stratum lucidum found and what is its characteristic?

    Found only in thick skin; it is a thin, translucent layer of dead keratinocytes above the stratum granulosum.

  • What is the role of the stratum corneum?

    It consists of 20–30 layers of dead, keratinized cells that protect against abrasion, water loss, and environmental damage.

  • What are the two layers of the dermis?

    The dermis has two layers: papillary layer (areolar connective tissue) and reticular layer (dense irregular connective tissue).

  • What is the function of dermal papillae?

    Dermal papillae are fingerlike projections in the papillary layer that contain capillaries and sensory receptors, enhancing nutrient delivery and touch sensation.

  • What are cleavage lines and why are they important?

    Cleavage lines are separations between collagen fiber bundles in the reticular dermis; incisions parallel to these lines heal better.

  • What causes stretch marks (striae)?

    Extreme stretching of skin causes dermal tears, resulting in silvery white scars called striae or stretch marks.

  • What pigments contribute to skin color?

    1. Melanin (made by melanocytes)
    2. Carotene (yellow-orange pigment)
    3. Hemoglobin (pinkish hue from blood)

  • What is the function of melanin in the skin?

    Melanin protects keratinocyte DNA from UV damage by absorbing harmful radiation.

  • What are the main functions of hair?

    Hair warns of insects, protects against physical trauma, reduces heat loss, and shields skin from sunlight.

  • What are the three parts of a hair shaft?

    Medulla (central core), cortex (surrounding layers), and cuticle (outer layer of overlapping cells).

  • What is the arrector pili muscle?

    A small band of smooth muscle attached to hair follicles that causes hair to stand up, producing goosebumps.

  • What are the two main types of sweat glands?

    Eccrine (merocrine) glands for thermoregulation and apocrine glands found in axillary and anogenital areas, producing milky sweat.

  • What is sebum and which gland produces it?

    Sebum is an oily holocrine secretion produced by sebaceous glands that softens hair and skin and has bactericidal properties.

  • What are the main functions of the skin?

    Protection, body temperature regulation, cutaneous sensations, metabolic functions, blood reservoir, and excretion of wastes.

  • What are the three types of barriers the skin provides?

    Chemical barrier (acid mantle, antimicrobial secretions), physical barrier (keratinized cells and glycolipids), and biological barrier (immune cells and DNA protection).

  • How does the skin regulate body temperature?

    By sweating (insensible and sensible perspiration) and adjusting blood flow through dermal vessels.

  • What is the ABCDE rule for melanoma detection?

    A: asymmetry, B: border irregularity, C: color variation, D: diameter > 6 mm, E: evolution or change over time.

  • How are burns classified by severity?

    First-degree: epidermal damage only; second-degree: epidermal and upper dermal damage; third-degree: full thickness skin damage.

  • What is the Rule of Nines in burn assessment?

    The body is divided into 11 areas each representing 9% of total body surface to estimate burn extent and fluid loss.

  • What changes occur in aging skin?

    Slower epidermal replacement, thinner and drier skin, decreased subcutaneous fat and elasticity, increased cancer risk, and hair thinning.