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Integumentary System - Anatomy & Physiology

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Terms in this set (21)

  • What are the two main regions of the skin?
    Epidermis (superficial, epithelial, avascular) and Dermis (underlying, fibrous connective tissue, vascular).
  • What is the hypodermis and its function?
    A subcutaneous layer deep to the skin, mostly adipose tissue that absorbs shock, insulates, and anchors skin to underlying structures.
  • Name the layers of the epidermis from deep to superficial.
    Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (only in thick skin), and stratum corneum.
  • What are the four main cell types in the epidermis?
    Keratinocytes, melanocytes, dendritic (Langerhans) cells, and tactile (Merkel) cells.
  • What is the function of keratinocytes?
    Produce fibrous protein keratin, form most epidermal cells, tightly connected by desmosomes, and are replaced every 25-45 days.
  • What role do melanocytes play in the skin?
    Produce melanin pigment, which protects keratinocyte nuclei from UV damage by forming pigment shields.
  • Describe the stratum basale.
    Deepest epidermal layer with a single row of mitotic stem cells; some become keratinocytes, others remain stem cells; contains melanocytes.
  • What characterizes the stratum spinosum?
    Several layers of keratinocytes connected by desmosomes with abundant 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.
  • Where is the stratum lucidum found and what is its characteristic?
    Only in thick skin; a thin, translucent band of a few rows of flat, dead keratinocytes above the stratum granulosum.
  • What is the stratum corneum composed of and its function?
    20-30 layers of dead, flat, keratinized cells that protect deeper layers from environment, water loss, abrasion, and penetration.
  • What are the two layers of the dermis?
    Papillary layer (areolar connective tissue with collagen and elastic fibers) and reticular layer (dense fibrous connective tissue).
  • What are dermal papillae and their function?
    Peglike projections in the papillary layer containing capillary loops and sensory receptors; form friction ridges (fingerprints).
  • What are cleavage lines in the dermis?
    Patterns of collagen fibers in the reticular layer that run parallel to the skin surface; important for surgical incisions.
  • What pigments contribute to skin color?
    Melanin (only pigment made in skin), carotene (yellow-orange pigment), and hemoglobin (pinkish hue in fair skin).
  • What are the main functions of the integumentary system?
    Protection, body temperature regulation, cutaneous sensation, metabolic functions, blood reservoir, and excretion.
  • What are the three types of barriers provided by the skin?
    Chemical barriers (skin secretions, melanin), physical barriers (keratinized cells and glycolipids), and biological barriers (immune cells).
  • Describe the difference between eccrine and apocrine sweat glands.
    Eccrine glands regulate temperature by producing watery sweat; apocrine glands produce viscous sweat in axillary and anogenital areas, starting at puberty.
  • What is the function of sebaceous glands?
    Secrete oily sebum that softens hair and skin and has bactericidal properties; mostly associated with hair follicles.
  • What are the three major types of skin cancer?
    Basal cell carcinoma (least malignant), squamous cell carcinoma (can metastasize), and melanoma (most dangerous, from melanocytes).
  • How are burns classified by severity?
    First-degree (epidermal damage), second-degree (epidermal and upper dermal damage with blisters), and third-degree (full thickness, nerve endings destroyed).