Integument A&P

Functions of the Integumentary System

  • Protection

    • Protects against pathogens, preventing infections.

    • Shields underlying tissues (fat, muscles, bones) from physical damage (e.g., injuries).

    • Guards against UV rays using melanin, which darkens skin in response to sun exposure.

    • Prevents dehydration, retaining bodily fluids and moisture beneath the skin.

  • Temperature Regulation

    • Helps maintain body temperature through perspiration.

    • During exercise, muscle activity raises internal temperature.

    • Skin's sweat glands release sweat (primarily water) which evaporates to cool the body.

    • Blood vessels in the skin can dilate, increasing blood flow to the surface to release heat (e.g., red cheeks when exercising).

  • Excretion

    • Sweat contains waste products (e.g., salts, organic materials) that are eliminated through the skin.

  • Sensation

    • Contains nerve endings that allow perception of pain, pressure, and temperature.

    • Different types of nerve receptors contribute to feeling various stimuli.

Anatomy of the Skin

  • Three Main Layers

    • Epidermis:

      • Outermost layer; contains melanocytes producing melanin.

      • Composed of soft keratin.

      • Dermal papillae form fingerprints.

    • Dermis (True Skin):

      • Middle layer; thickest, contains blood vessels, nerves, sweat glands, sebaceous (oil) glands, and hair follicles.

      • Provides strength and elasticity.

    • Hypodermis (Subcutaneous Layer):

      • Deepest layer; contains lipocytes (fat cells) for insulation.

      • Varies in thickness depending on body fat.

Accessory Structures of the Skin

  • Sebaceous Glands:

    • Produce oil to moisturize the skin, prevent dryness, and possess antibacterial properties.

  • Sweat Glands:

    • Responsible for perspiration, helping with cooling and excretion of waste.

    • Primary component: 99% water, plus salts.

  • Hair Follicles and Hair:

    • Hair grows from follicles located in the dermis; contains erector pili muscles that create goosebumps when contracted.

Burns

  • Classification:

    • First Degree:

      • Affects only the epidermis; symptoms include redness (erythema) and sensitivity, no blisters.

    • Second Degree:

      • Affects both epidermis and dermis; symptoms include redness, pain, swelling, and blisters (e.g., severe sunburn).

    • Third Degree:

      • Full-thickness burn affecting all layers including hypodermis; symptoms include anesthesia (loss of sensation) and possibly charred tissue.

Treatment of Burns

  • Immediate Concerns:

    • Fluid Loss: Significant loss can lead to hypovolemic shock and drop in blood pressure.

    • Infection Risk: Open wounds can become contaminated; burn units are used to control patient environments.

  • Treatments:

    • IV fluids administered to prevent dehydration and maintain blood pressure.

    • Antibiotics may be given to prevent infection.

    • Debridement: Removal of dead tissue to prepare for skin grafts.

    • Skin Grafting:

      • Autografts (from the same patient) are common; may also use donor skin (e.g., pig skin, cadaver skin).

      • The procedure involves cutting skin from a donor site and implanting it on the burn site, aiming for healing and function.

Conclusion

  • Understanding the integumentary system's functions, structure, and the effects of burns is crucial for medical professionals, especially in emergency settings.