Integumentary System Overview and Key Concepts

Word Parts and Meanings

• Review of prefixes, suffixes, and stem word parts essential for understanding medical terminology.
• Key concepts are important in interpreting compound medical terms concerning the integumentary system.

Integumentary System Overview

• Integument: Refers to covering; the skin is the largest organ of the body.
  • Prevents foreign organisms from entering and causing diseases.
• Cutus and derma: Both mean skin; integral to understanding skin anatomy.

Structure of the Skin

• Epidermis: The outermost layer; characterized by keratinized cells which move upward and die.
• Dermis: The true skin layer; contains nerves, blood vessels, lymphatics, glands, and collagen.

Key Layers of the Epidermis

1. Stratum Corneum: Outermost layer made of dead, keratinized cells.
   • Continually shed and replaced; approximately 1.6 pounds of skin is shed in a year.
2. Stratum Germinativum: The basal layer that produces new skin cells.
   • Contains melanocytes that produce melanin, influencing skin color.

Skin Functions and Characteristics

• Keratin: Protein that creates a waterproof barrier.
• Skin renewal: New cells migrate from the stratum germinativum to the corneum monthly.
• Papillary layer: Upper dermis region that forms fingerprints and provides strength.

Skin Appendages and Functions

• Sebaceous glands: Produce oil; play a role in skin lubrication.
• Sweat glands: Help regulate body temperature through secretion.
• Hair follicles and erector pili muscles: Contribute to thermal regulation.

Sensory Receptors in the Skin

• Meissner's corpuscles: Detect light pressure and touch.
• Pacinian corpuscles: Sensitive to deep pressure.
• Free nerve endings: Pain and temperature receptors; respond to intense stimuli.

Common Skin Disorders and Conditions

• Acne: Inflammatory skin disease; caused by clogged sebaceous glands.
• Burns: Classified by degrees:
  • First: Redness without damage.
  • Second: Blisters present.
  • Third: Damage to deeper layers; may require skin grafts.
  • Fourth: Extensive damage to underlying tissues.

Types of Skin Lesions

• Primary lesions include:
  • Bulla: Large fluid-filled lesions.
  • Papule: Small elevated lesions.
  • Nodule: Solid raised areas; larger than papules.
• Secondary lesions include:
  • Keloids: Raised scars from excessive tissue development.
  • Ulcers: Deep skin depressions that can become infected.

Skin Infections and Allergies

• Urticaria: Hives caused by allergic reactions; characterized by itchy raised welts.
• Eczema: Non-infectious inflammation characterized by redness, swelling, and itching.

Treatment and Procedures

• Dermoplasty: Skin repair surgery; includes techniques like dermabrasion and skin grafting.
• Injections: Types include intramuscular and subcutaneous for various conditions.
• Antibiotics and corticosteroids: Common treatments for infections and inflammatory skin conditions.

Special Conditions and Treatments

• Pilonidal cyst: Often develops in the sacral area; may require surgical drainage.
• Millia: Small keratin-filled cysts that typically resolve without treatment.
• Psoriasis: Chronic skin condition characterized by red patches and silvery scales; various treatment options exist, including phototherapy.

Summary of Skin Functions

• Skin plays crucial roles in protection, sensation, thermoregulation, and vitamin D synthesis.
• Understanding skin structure, functions, and disorders is essential for medical professionals.