the intergumentary system

• What is dermatology the study of?

  Skin
• What are the two distinct layers of the skin?

  Epidermis and dermis
• What type of epithelium makes up the epidermis?

  Keratinised stratified squamous epithelium
• What is the primary function of the epidermis?

  It serves as a tough, waterproof outer layer
• What is the composition of the dermis?

  Arealor and adipose connective tissue containing collagen and elastic fibers
• What structures are contained within the dermis?

  Nerves, blood vessels, sweat glands, and hair roots
• What are the five layers of the epidermis from bottom to top?

  1. Stratum basale (basal cell layer)
  2. Stratum spinosum (prickle cell layer)
  3. Stratum granulosum (granular cell layer)
  4. Stratum lucidum (clear cell layer)
  5. Stratum corneum (horny-cell layer)
• What is the function of the stratum basale?

  It constantly produces new cells that are pushed upwards
• What occurs in the stratum spinosum?

  Some cells divide while others are keratinised
• What do keratinocytes produce?

  Keratin
• What happens in the stratum granulosum?

  Skin cells begin to die as they become increasingly keratinised
• What is the role of the stratum lucidum?

  It serves as the waterproof layer of dead cells
• What characterizes the stratum corneum?

  It is the outermost layer with strong, tough, dead cells full of keratin
• What is the process called when skin cells are shed?

  Desquamation
• What pigment do melanocytes produce?

  Melanin
• What is the function of melanin?

  It contributes to skin color and absorbs UVR from the sun
• What are the two layers of the dermis?

  1. Superficial papillary layer
  2. Reticular layer
• What is the function of the superficial papillary layer?

  It has finger-like projections that contain loops of capillaries and nerve endings sensitive to touch
• What does the reticular layer house?

  Hair follicles, nerves, oil glands, ducts of sweat glands, and adipose tissues
• What is the subcutaneous layer also known as?

  Hypodermis
• What is the function of the subcutaneous layer?

  It attaches the reticular layer to the underlying organs and contains areolar and adipose connective tissues
• What does the subcutaneous layer help with?

  It makes the skin elastic and helps withstand pulling pain
• What is the largest organ in the human body?

  Skin
• How much can the skin weigh?

  Up to 5 kg
• What is the approximate thickness of skin?

  As thin as 0.5 mm
• How does skin reflect our health?

  It reflects the state of our health and emotion
• What are the different skin types and their characteristics?

  • Determines sebum production by sebaceous glands
  • Presence or lack of moisture
  • Shows areas of skin irritation (e.g., sensitive skin)
  • Signs of aging (e.g., dry, thin, lacks elasticity, easily damaged)
• What are the main functions of the skin?

  1. Sensation: Cutaneous sensory receptors for touch, temperature, pressure, and pain
  2. Absorption: Absorbs certain substances
  3. Protection: Against trauma, bacteria, dehydration, UVR, chemicals, and thermal damage
  4. Heat regulation: Through sweating and vasodilation or vasoconstriction
  5. Excretion: Excretes wastes
  6. Secretion: Secretes sebum for skin suppleness and waterproofing
  7. Vitamin D synthesis: Regulates calcium levels for growth and bone strength
• What are the three types of hair?

  Lanugo, Vellus, Terminal
• What is lanugo?

  Soft hair only found in foetus
• Where is vellus hair found?

  All over the body except palms, soles, eyelids, lips, and nipples
• What characterizes terminal hair?

  Long, coarse hair found on the head, eyebrows, eyelashes, armpits, and pubic areas
• What is the structure of hair?

  • Composed of columns of keratinized dead cells
  • Grows out of hair follicles
  • Made up of shaft (superficial end) and root (penetrates the dermis)
• What do arrector pili muscles do?

  They pull the hair up to a vertical position in response to cold, fight, or emotions
• What are the functions of hair?

  • Provide warmth
  • Provide protection
• What are common pathologies of the skin?

  Skin disorders, burns, and pressure ulcers
• How does nutrition affect skin health?

  Nutrition provides essential vitamins and minerals that support skin function
• Why is exercise important for skin health?

  Exercise improves circulation, which helps deliver nutrients to the skin
• What is the role of water intake in skin health?

  Water intake keeps the skin hydrated and maintains its elasticity
• How does rest, relaxation, and sleep contribute to skin health?

  Rest and sleep allow the skin to repair and regenerate