Skin Structure and Function Quiz

Skin Structure and Function

• Skin is the largest organ, acting as a barrier between internal and external environments, reflecting overall health. It comprises 16% of an adult's total body weight.
• Two main layers:
  • Epidermis: Superficial, thinner, epithelial tissue
  • Dermis: Deeper, thicker, connective tissue
• Subcutaneous layer (hypodermis): Deep to the dermis, not part of the skin, composed of areolar and adipose connective tissue, attaching skin to underlying tissues.
• Accessory structures: Hair, skin glands, nails

Skin Functions

• Appearance: Reflects overall health.
• Protection: From pathogens (e.g., Langerhans cells).
• Storage: Lipids (fats) and water.
• Sensation: Nerve endings detect various stimuli (temperature, pressure, vibration, touch, injury).
• Water control: Prevents water loss through evaporation.
• Thermoregulation: Regulates body temperature.

Physical Assessment of Skin

• Patient preparation: Explain procedures, ensure privacy, comfortable temperature and positioning, remove clothing, examination gown. Lighting is important. Clean hands and wear gloves.
• Generalized color inspection:
  • Pallor: Loss of color, due to insufficient blood supply or anemia.
  • Cyanosis: Bluish or grayish discoloration, from vasoconstriction, heart attack, or lung problems.
  • Jaundice: Yellowing of skin, sclera, and mucous membranes, caused by high bilirubin (a breakdown product of red blood cells).
  • Ecchymosis: Discoloration from skin bleeding underneath, typically from bruising
  • Petechiae: Tiny purple, red, or brown spots, often on arms, legs, abdomen, and buttocks.
  • Cyanosis: Bluish discoloration from low oxygen levels in blood
• Skin integrity: Check pressure points (sacrum, hips, elbows) for any redness or breakdown (initial sign of ulcers).
• Lesion inspection: Note color, elevation/depression, shape, location, distribution, size, and exudates. Use magnifying glass, if necessary. Normal findings include stretch marks, healed scars, freckles.
• Texture palpation: Using fingertips, assess for smoothness, roughness, flakiness, dryness.
• Thickness palpation: Using finger pads, assess for normal thinness.
• Temperature palpation: Using back of hands, assess for normal warmth.
• Moisture palpation: Assess exposed areas for moisture level (varied according to exposed locations).
• Mobility and turgor: Assess ease of skin pinching and return to original position.
• Edema palpation: Assessing for skin indentation that persists after pressure release.
• Edema classifications:
  • Localized: Swelling in a specific region
  • Generalized (anasarca): Generalized swelling
  • Types based on consistency
    • Pitting: soft, indentation persists after pressure removal.
    • Non-pitting: Hard, indentation does not persist
  • Types based on cause: Inflammatory, obstructive, cardiac, nutritional (hypoproteinemia), renal edema (nephritic and nephrotic).
• Nail inspection:
  • Grooming & cleanliness: Assess for cleanliness and normal nail shape.
  • Color & markings: Assess for normal pink tones, some longitudinal ridges. Look for pale, cyanotic, or yellow discoloration, splinter hemorrhages
  • Consistency: Inspect for firmness and attachment to nail bed. Paronychia (inflammation) and onycholysis (detachment) are abnormal findings.

Skin Lesions

• Skin lesions are abnormal skin changes (primary or secondary).
• Secondary Lesions: Caused by changes in primary lesions (e.g., a crust forming from scratched eczema). Examples include atrophy (thinning, transparency, wrinkling) and crusts (dried fluid, like pus, blood, or serum).