INTEGUMENTARY (ANAPHY)

FOR P1 HUHUHUHHU

Epidermis

The superficial, thinner portion of the skin composed of keratinized stratified squamous epithelium.

Stratum Corneum

The topmost layer of the epidermis made of dead, flattened keratinocytes; acts as a tough, protective barrier against the environment.

Stratum Lucidum

A thin, clear layer of dead skin cells found only in thick skin (palms and soles); provides an extra layer of protection.

Stratum Granulosum

The middle layer where keratinocytes begin to die and form a waterproof barrier by producing keratohyalin and lamellar bodies.

Stratum Spinosum

Also called the "prickle cell layer," this layer provides strength and flexibility to the skin through desmosome connections between keratinocytes.

Stratum Basale / Germinativum

The deepest layer of the epidermis where mitosis (cell division) occurs; contains melanocytes and basal cells that regenerate new skin cells

Dermis

The second, deeper part of the skin; composed of dense irregular connective tissue containing collagen and elastic fibers.

Papillary Region

The upper part of the dermis composed of loose connective tissue; contains dermal papillae that form fingerprints and supply nutrients to the epidermis.

Reticular Region

The deeper part of the dermis made of dense irregular connective tissue; provides skin with strength and elasticity and contains larger blood vessels and sensory receptors.

Hypodermis / Subcutaneous Tissue

The deepest layer of skin composed mainly of fat and connective tissue; provides insulation, cushioning, and energy storage.

Keratinization

The process by which skin cells (keratinocytes) mature and move from the stratum basale to the stratum corneum, gradually accumulating keratin (a tough, fibrous protein) and dying. This transformation creates a protective, waterproof outer layer of dead skin cells that helps prevent water loss and protects against environmental damage.

Melanocytes

melanin-producing cells

High number

in the epidermis of the penis, nipples of the breasts, and just around the areolae, face, and limbs

Low numbers

lips, palms, mucous membranes

Eumelanin

type of melanin from brown to black

Pheomelanin

type of melanin from yellow to red

Melanin Production

The process by which specialized cells called melanocytes, located in the stratum basale of the epidermis, produce melanin, a pigment responsible for skin, hair, and eye color.

Genetic Factors

Your genes determine the number and activity of melanocytes.

Exposure to Light (UV Radiation)

Sunlight stimulates melanocytes to produce more melanin as a protective response to UV radiation, resulting in tanning.

Hormones

Certain hormones, like melanocyte-stimulating hormone (MSH), can increase melanin production.

Freckle, Age Spot & Mole

Accumulation Of Melanin

Thin Skin

Covers entire body except palms, soles, and palmar side of fingers/toe

Thick Skin

Found only on palms, soles, and palmar side of fingers/toes

0.10 - 0.15

Thickness of Thin skin

0.6 - 4.5

Thickness of Thick skin

Hair

Present on most skin surfaces except the palms, palmar surfaces of the fingers, the soles, and plantar surfaces of the feet. Heavily distributed across the scalp, in the eyebrows, armpits, and around the external genitalia in adults.

Hair Follicle

A tube-like structure in the dermis where hair grows; surrounds the hair root and is made up of connective and epithelial tissues.

Epithelial Root Sheath

The inner lining of the hair follicle made of epithelial cells; it has two layers:

External Root Sheath

continuous with the epidermis; provides structure.

Internal Root Sheath

surrounds the hair shaft; helps shape the hair.

Bulb

The enlarged base of the hair follicle; contains the hair matrix (actively dividing cells) and the papilla (with blood vessels that nourish the hair).

Shaft

The visible part of the hair above the skin surface; made of dead, keratinized cells.

Hair Root Plexus

A network of nerve endings wrapped around the hair follicle; detects hair movement and sends touch sensations to the brain.

Root

The portion of the hair below the skin surface, embedded in the follicle; anchors the hair to the skin.

Medulla, Cortex and Cuticle

Three Concentric Layers

Medulla

The central core; present in thick hair, contains soft keratin and air spaces.

Cortex

The middle layer; provides strength, color, and texture due to hardened keratin and pigment.

Cuticle

The outer layer; composed of overlapping flat cells that protect the hair

Growth stage Regression stage Resting stage

The three stages of Hair Growth

Normal hair loss in adult scalp

– 70-100 hairs per day

Lanugo, Vellus and Terminal Hairs

Types of Hair

Hair Color

Determined by the amount and type of melanin in the keratinized cells.

Hair becomes gray

when there is a progressive decline in melanin granules

White hair

results from the lack of melanin and the accumulation of air bubbles in the shaft.

Skin Glands

Epithelial cells that secrete a substance.

Sebaceous (Oil) Glands

Lubricates skin and hair, prevents water loss, keeps skin soft, and limits bacterial growth.

Eccrine and Apocrine

Two types of sweat glands

Eccrine Sweat Glands

Regulates body temperature, removes wastes, and activated by emotional stress.

Apocrine Sweat Glands

Active during emotional stress and sexual arousal.

Ceruminous Glands

Traps foreign particles, repels insects, keeps ear canal waterproof, and protects against microbes.

Nails

Plates of tightly packed, hard, dead, keratinized epidermal cells that form a clear, solid covering over the dorsal surfaces of the distal portions of the digits.

Average nail growth:

1 mm (0.04 in.) / week

Thermoregulation

The skin helps maintain a stable body temperature by sweating to cool the body and constricting or dilating blood vessels to retain or release heat.

Synthesis of Vitamin D

When exposed to UV rays, the skin synthesizes vitamin D precursor molecules, which are then converted into active vitamin D (calcitriol) needed for calcium absorption in the intestines.

Thermoregulation • Blood reservoir • Protection • Cutaneous sensation • Excretion and absorption • Synthesis of vitamin D

physiology of integumentary system

Skin Wound Healing

Skin damage sets in motion a sequence of events that repairs the skin to its normal (or near-normal) structure and function.

Epidermal Wound Healing

A healing process that occurs when only the epidermis is damaged (e.g., abrasions or minor burns)

Deep Wound Healing

Occurs when the injury extends through the dermis and subcutaneous layer.

Fibrosis

The formation of excess fibrous connective tissue (scar tissue) during the healing of deep wounds.

Thermal Burns

Skin injuries caused by exposure to excessive heat/cold temperatures

1st Degree Burn

A superficial burn that affects only the epidermis, causing redness, dryness, and tender pain, with minimal swelling and no scarring as it heals spontaneously.

2nd Degree Burn (Superficial Partial-Thickness)

A burn that involves the epidermis and upper dermis, resulting in bright red or pink skin, moist blisters, and severe pain, with moderate swelling, minimal scarring, and spontaneous healing.

2nd Degree Burn (Deep Partial-Thickness)

This burn damages the epidermis and deeper dermis, appearing mixed red and waxy white, with broken blisters, pressure sensitivity, slow healing, and often leads to excessive scarring.

3rd Degree Burn (Full-Thickness)

A severe burn destroying the entire epidermis and dermis, characterized by white, black, or leathery skin, no pain due to nerve damage, sunken appearance, and requiring skin grafting with significant scarring.

RULE OF NINES

Estimates the Total Body Surface Area (TBSA) affected by burns.

PRESSURE ULCERS

form as a result of constant or prolonged pressure exerted on the skin.

4th Degree Burn

A life-threatening burn that extends through the skin into underlying fat, muscle, and bone, presenting with blackened, charred, or exposed tissues, no sensation due to total nerve destruction, and requiring extensive surgical treatment with permanent disability or amputation likely.

9%

Rule of Nines for Adults (Head and neck)

9% (4.5 front and back)

Rule of Nines for Adults (each Arm)

18% (9% front, 9% back)

Rule of Nines for Adults (Each Leg)

18%

Rule of Nines for Adults (Front of torso)

18%

Rule of Nines for Adults (Back of Torso)

1%

Rule of Nines for Adults (Perineum or genital area)

18%

Rule of Nines for Children (Head and Neck)

9% (4.5 front and back)

Rule of Nines for Children (each arm)

14% (7% front and back)

Rule of Nines for Children (Each Leg)

18%

Rule of Nines for Children (Front of torso)

18%

Rule of Nines for Children (Back of Torso)

1%

Rule of Nines for Children (Perineum or Genital area)