integumentary system

• What is the integumentary system primarily composed of?

  The integumentary system is primarily composed of skin.

  
• What are the two distinct regions of the skin?

  • Epidermis
  • Dermis
• What are the main functions of the skin?

  • Protection
  • Synthesizes vitamin D with UV
  • Homeostasis
  • Sensory reception (nerve endings)
• What are the four basic types of tissue in the body?

  • Epithelium
  • Connective tissue
  • Muscle tissue
  • Nervous tissue
• What are the fiber types present in the dermis?

  Collagen, elastic, and reticular fibers.
• What types of cells are found in the dermis?

  Fibroblasts, macrophages, mast cells, and white blood cells (WBCs).
• What type of tissue is the dermis primarily composed of?

  The dermis is primarily composed of strong, flexible connective tissue.
• What are the two layers of the dermis?

  • Papillary layer: areolar connective tissue; includes dermal papillae
  • Reticular layer: network of collagen and reticular fibers
• What is the critical role of the dermis in temperature regulation?

  The dermis contains blood vessels that help regulate temperature.
• What do dermal papillae do?

  Dermal papillae elevate the overlying epidermis into epidermal ridges.
• What are fingerprints and how are they formed?

  Fingerprints are formed by dermal papillae lying atop dermal ridges.
• What are flexion creases?

  Flexion creases are deep dermis folds from continual folding.
• What is the function of collagen fibers in the dermis?

  Collagen fibers provide strength and resilience.
• What are striae?

  Striae are stretch marks caused by elastic fibers.
• What are tension lines in the skin?

  Tension lines are the direction the bundles of fibers are directed.
• What is the hypodermis also known as?

  The hypodermis is also known as subcutaneous tissue or superficial fascia.
• What is the primary function of the hypodermis?

  The hypodermis stores fat and anchors the skin.
• How does melanin transfer to keratinocytes?

  Melanin in granules passes from melanocytes to keratinocytes in stratum basale.
• What are the three skin pigments?

  • Melanin: the most important
  • Carotene: from carrots and yellow vegetables
  • Hemoglobin: gives pink color to light skin
• What is the role of hair in the integumentary system?

  Hair provides warmth, senses light touch, and offers protection.

  
• What are the parts of hair?

  • Root: imbedded in skin
  • Shaft: projecting above skin surface
  • Made of hard keratin
• What are the three concentric layers of hair?

  • Medulla: core
  • Cortex: surrounds medulla
  • Cuticle: single layer, overlapping
• What are the types of hair?

  • Vellus: fine, short hairs
  • Intermediate hairs
  • Terminal: longer, courser hair
• What is the average hair growth rate?

  Hair grows at an average rate of 2 mm/week.
• What causes hair loss in individuals?

  Hair loss can be caused by thinning related to age and male pattern baldness.
• What determines hair color?

  • Amount of melanin for black or brown hair
  • Distinct form of melanin for red hair
  • White hair: decreased melanin and air bubbles in the medulla
• Where are sebaceous glands located?

  Sebaceous glands are located all over the body except for palms and soles.
• What is the function of sebaceous glands?

  Sebaceous glands produce sebum to lubricate the skin.
• What is the primary function of sweat glands?

  Sweat glands prevent overheating by producing sweat.
• How much sweat can humans produce in a day?

  Humans can produce 500 cc to 12 liters of sweat per day.
• What are the two types of sweat glands?

  Eccrine (merocrine) and apocrine sweat glands.
• What are the characteristics of eccrine sweat glands?

  • Most numerous sweat glands
  • Produce true sweat: 99% water, some salts, traces of waste
  • Open through pores
• What are the characteristics of apocrine sweat glands?

  • Located in axillary, anal, and genital areas
  • Ducts open into hair follicles
  • Decompose over time, causing odor
• What are modified apocrine glands?

  • Ceruminous glands: secrete earwax
  • Mammary glands: secrete milk
• What are the types of burns?

  • First degree: epidermis only; redness (e.g., sunburn)
  • Second degree: epidermis and upper dermis; blister
  • Third degree: full thickness
• What are critical burns?

  Critical burns are over 10% of the body with third-degree burns or 25% with second-degree burns.
• How is the extent of burns estimated?

  The extent of burns is estimated by the "rule of 9's."

  
• What are the types of skin tumors?

  • Benign: e.g., warts
  • Cancer: associated with UV exposure
  • Aktinic keratosis: premalignant
  • Basal cell carcinoma: cells of stratum basale
  • Squamous cell carcinoma: keratinocytes
  • Melanoma: melanocytes (most dangerous)
• What does the acronym ABCD stand for in melanoma recognition?

  A stands for Asymmetry, B for Border irregularity, C for Colors, and D for Diameter larger than 6 mm.
• What is the immune system's primary function?

  • The immune system is the body’s response to disease and injury.
  • It includes both nonspecific (innate) and specific (acquired) responses.