chapter 5

Chapter 5: Integument

Overview

  • Focuses on the integumentary system, including skin structure and functions.

  • Discusses burns, skin color, skin disorders, and skin appendages.

Burns

Types of Burns

  • First-degree burns:

    • Damage limited to epidermis.

    • Skin appears red and swollen.

  • Second-degree burns:

    • Affects epidermis and upper dermis.

    • Skin is red and has blisters.

  • Third-degree burns:

    • Destroys entire skin layer.

    • Affected area is painless; color can be gray-white or black.

  • Fourth-degree burns:

    • Involves complete thickness of skin, including adipose tissue, tendons, ligaments, and muscle.

  • Fifth and sixth-degree burns:

    • Burn extends to bone.

Escharotomy

  • Surgical incision through eschar (thick tissue) is made to relieve intra-compartment pressure.

Critical Burn Assessment

  • 25% body surface area with 2nd degree burns is critical.

  • 10% body surface area with 3rd degree burns is critical.

  • 3rd degree burns on face, hands, or feet are also critical.

Rule of Nines

  • Method to estimate severity of burns:

    • Over 25% body area with second-degree burns.

    • Over 10% body area with third-degree burns.

    • Third-degree burns on exposed areas such as face and hands.

Causes of Burns

  • Include hot water, sunlight, radiation, electrical shock, and chemical exposure (acids and bases).

  • Complications can lead to significant fluid loss and infection.

Treatment of Burns

  • First-degree burns: Treated with topical creams to relieve pain.

  • Second-degree burns: Require blister management and potential grafts if severe.

  • Third-degree burns: Typically necessitate IV nutrition, fluid replacement, debridement, and infection control.

Skin Layers and Functions

Skin Composition

  • Epidermis: Keratinized stratified squamous epithelium.

  • Dermis: Connective tissue layer containing sensory receptors, hair follicles, sebaceous glands, and sweat glands.

  • Hypodermis: Contains adipose tissue, serving as energy reservoir and thermal insulator.

Functions of the Skin

  • Resistance to trauma and infection (keratin and desmosomes).

  • Protection against ultraviolet light.

  • Vitamin D synthesis.

  • Sensory perception and thermoregulation.

Skin Colors and Pigmentation

Factors Influencing Skin Color

  • Hemoglobin: Red pigment in blood.

  • Melanin: Yellow, brown, and black hues; synthesized in response to UV light.

  • Carotene: Yellow pigment accumulated in the stratum corneum and fat.

Conditions Affecting Skin Color

  • Albinism: Lack of pigmentation due to a genetic mutation affecting melanin production.

  • Cyanosis: Blue discoloration caused by oxygen deficiency.

  • Erythema: Redness from vascular dilation.

  • Jaundice: Yellowing from excess bilirubin, often associated with liver disease.

Skin Appendages

Hair

  • Composed of hard keratin.

  • Three types of hair:

    • Lanugo: Fine, unpigmented fetal hair.

    • Vellus: Fine, unpigmented hair of children and women.

    • Terminal hair: Coarse, long, pigmented hair on the scalp.

Nails

  • Composed of keratinized cells.

  • Structure includes nail body, nail bed, eponychium (cuticle), and lunule.

Skin Disorders

Infections and Conditions

  • Common infections include athlete's foot (fungal), boils (bacterial), and cold sores (viral).

  • Allergies such as contact dermatitis and conditions like psoriasis.

Skin Cancer

  • The most frequent form of cancer.

  • Types include:

    • Basal Cell Carcinoma: Least malignant, arises from stratum basale.

    • Squamous Cell Carcinoma: Can metastasize, usually sun-induced.

    • Malignant Melanoma: Most deadly, detected by the ABCD rule (Asymmetry, Border irregularity, Color variation, Diameter).

Conclusion

  • The integumentary system plays a critical role in protection, sensation, and regulation. Understanding burns, skin color variations, and skin disorders is essential for recognizing health issues.