Integumentary System Overview

Definition: The integumentary system comprises the skin, hair, and nails.
Functions of the Skin:
  - Protects the body from invasion by microorganisms, chemicals, and environmental factors.
  - Prevents dehydration.
  - Acts as a sensory organ.
  - Modulates body temperature and electrolyte balance.
  - Synthesizes vitamin D.

Layers of the Skin:
  - Epidermis:
    - Uppermost thin layer made of closely packed epithelial cells.
  - Dermis:
    - Inner thick layer containing blood vessels, hair follicles, sweat glands, and nerve fibers.
  - Hypodermis (Subcutaneous Layer):
    - Lies beneath the dermis; contains connective and adipose (fat) tissue.
Sensory Function:
- Specialized sensory nerve structures in the epidermis, dermis, and hypodermis detect touch, temperature, and pain.

Pigments Involved:
  - Melanin:
    - Produced by melanocytes in the epidermis.
    - Accumulations lead to freckles.
    - Darker skin types have more melanin than lighter skin types.
    - UV exposure increases melanin production, resulting in tanning.
  - Carotene:
    - Contributes to skin color.
  - Hemoglobin:
    - Influences skin color alongside melanin.

Health Implications of UV Exposure:
- Can lead to skin wrinkling and DNA damage, increasing skin cancer risk.
- Melanocytes aggregation forms moles; monitoring for changes is crucial.
ABCDE Rule for Melanoma:
  - Asymmetrical: Sides of the mole are not symmetrical.
  - Borders: Irregular edges.
  - Color: Various shades rather than uniform.
  - Diameter: Larger than 6 mm (0.24 in).
  - Evolving: Changes in size, shape, color, or elevation.

Composition: Made of dead, keratinized cells from hair follicles in the dermis.
Functions of Hair:
  - Protection (e.g., shielding the skull from sun).
  - Sensory input enhanced by the hair root plexus.
  - Thermoregulation and communication (marked by arrector pili muscles causing goosebumps).

Nail Bed: A specialized structure of the epidermis at the fingertip and toe tips.
Nail Body Functions:
- Protects fingertips from mechanical stress.
- Assists in picking up small objects.

Types:
  - Eccrine Sweat Glands:
    - Produce hypotonic sweat primarily for thermoregulation.
    - Located all over the skin, especially palms, soles, and forehead.
    - Mainly composed of water, with salts, antibodies, metabolic waste, and dermcidin.
  - Apocrine Sweat Glands:
    - Located in dense hairy areas (armpits, groin).
    - Produce thicker sweat with organic compounds, leading to odor when broken down by bacteria.
    - Influenced by the nervous system and hormones.

Definition of Lesion: An area of abnormal tissue.
Common Skin Lesion Terms and Definitions (Table 14.2):
  - Abscess: Localized pus collection.
  - Bulla (Bullae): Fluid-filled blister (≤ 5 mm).
  - Carbuncle: Deep pus-filled abscess.
  - Cyst: Encapsulated sac of fluid or semi-solid matter.
  - Folliculitis: Inflammation of hair follicles.
  - Furuncle (Boil): Pus-filled abscess in a hair follicle.
  - Macules: Smooth discoloration spots.
  - Papules: Small raised bumps (e.g., mosquito bites).
  - Pustules: Pus-filled bumps (e.g., acne).
  - Ulcer: Skin break or sore.
  - Vesicle: Small fluid-filled lesion (e.g., herpes blister).
  - Wheal: Inflamed, itchy area (often allergic).

Acne:
- Skin disturbance mainly in areas rich in sebaceous glands (e.g., face, back).
- Primarily associated with hormonal changes during puberty, leading to sebaceous gland overactivity.
Eczema (Atopic Dermatitis):
- Chronic inflammatory condition appearing as dry, itchy skin often in childhood.
- Associated with an overactive immune response.
Head Lice:
- Common in children (ages 3-11); transmitted by head-to-head contact.
- Symptoms include itching and sores from scratching.
Burns: Table of severity:
  - First-degree (Superficial): Affects epidermis; painful but heals in days.
  - Second-degree (Partial Thickness): Affects both epidermis and dermis; pain, swelling, and blisters.
  - Third-degree (Full Thickness): Extends through epidermis and dermis; requires medical attention.
  - Fourth-degree (Deep Full Thickness): Affects underlying muscle and bone; surgery may be necessary.

Basal Cell Carcinoma:
- Most common cancer in the U.S.; affects skin exposed to the sun.
- Starts in the epidermis; treatment includes surgery and ointments.
Squamous Cell Carcinoma:
- Finds lesions on scalp, ears, hands; can metastasize if untreated.
- Treated through surgery or radiation.
Melanoma:
- Uncontrolled melanocyte growth; most deadly skin cancer; arises from moles.
- Characterized by asymmetrical brown/black patches; treatment includes surgical excision and immunotherapy.

Tinea:
- Group of fungal infections including ringworm, athlete's foot, and jock itch.
- Symptoms include itching and burning; typically spread by contact.

Causes and Symptoms:
- Skin infection in children (ages 2-6) caused by staph or strep bacteria.
- Starts with red sores that fill with pus; highly contagious, treated with antibiotics.

Edema:
- Fluid accumulation in tissues, often linked to cardiovascular or renal disease.
Lymphedema:
- Swelling due to lymph fluid buildup; often occurs unilaterally following lymph node damage. Requires management strategies but has no cure.

Definition:
- Yellow skin and sclera due to excess bilirubin; liver dysfunction can cause it.
- Requires medical attention if new onset.

Definition:
- Damage to skin due to sustained pressure; high risk in immobile patients.
Braden Scale:
- Risk assessment tool assessing sensory perception, moisture, activity, mobility, nutrition, and friction/shear factors to prevent pressure injuries.

Phases:
  - Hemostasis: Blood vessels constrict, clotting stops bleeding (up to 60 min).
  - Inflammatory: White blood cells clean wound, appearance of swelling and erythema.
  - Proliferative: New tissue formation including granulation, angiogenesis, and collagen formation.
  - Maturation: Collagen matures, scars form, smoothing and lightening over time.

Primary Intention: Wounds closed via sutures; heals with minimal scarring.
Secondary Intention: Wounds heal from the bottom up; higher infection risk.
Tertiary Intention: Delayed closing due to infection, requiring additional intervention.

Assessment Components: Location, type, tissue damage, wound bed appearance, edges, infection signs, and pain.
Dressing Types: Sterile gauze, nonadherent dressings, hydrocolloids, etc. Each serves specific wound types and conditions.
Pain Management: Assess and administer medication pre-dressing change if indicated.