Integumentary System Lecture Notes

Overview of the Integumentary System

• The integumentary system is composed of the skin and its accessory structures, including hair, nails, and glands.
• Functions of the integumentary system:
  • Protection against environmental hazards
  • Regulation of body temperature
  • Sensory reception
  • Production of vitamin D
  • Excretion of wastes through perspiration

Structure of the Skin

• Epidermis: The outermost layer of skin
  • Composed of stratified squamous epithelium
  • Contains keratinocytes which produce keratin
  • Melanocytes produce melanin which gives skin its color
  • Langerhans cells are involved in immune response
  • Merkel cells function as touch receptors
• Dermis: Middle layer of skin
  • Composed of connective tissue
  • Contains collagen and elastin fibers
  • Houses blood vessels, nerves, hair follicles, and glands
• Hypodermis (Subcutaneous Layer): Deepest layer
  • Composed primarily of adipose tissue
  • Provides insulation and cushioning

Accessory Structures of the Skin

• Hair
  • Produced by hair follicles
  • Functions in protection and sensory input
• Nails
  • Composed of keratin
  • Protects the distal phalanx and enhances fine touch sensation
• Glands
  • Sebaceous glands produce sebum, an oily substance
  • Sweat glands help regulate body temperature and excrete wastes

Disorders of the Integumentary System

• Acne
  • Caused by clogged hair follicles with oil and dead skin cells
  • Involves sebaceous glands
• Psoriasis
  • Chronic condition characterized by red, scaly patches on the skin
  • Autoimmune nature
• Dermatitis
  • Inflammation of the skin, often resulting from an allergic reaction

Skin Healing and Repair

• Wound healing involves multiple stages: hemostasis, inflammation, proliferation, and remodeling
• Involves various cell types and biological processes to restore integrity

Review and Exam Preparation

• Focus on understanding the layers of the skin and their functions
• Know the accessory structures and their roles
• Be familiar with common disorders and their characteristics
• Review the processes involved in skin healing and repair

Additional Notes:

• This lecture focuses on the practical understanding of the skin’s anatomy and physiology.
• Pay attention to diagrams and images that illustrate skin structures for better comprehension.