Integumentary System and Skin Diseases

Integumentary System

Body system surrounding and protecting the body.

The 5 Components of the Integumentary System

1. Skin

2. Skin Appendages

3. Subcutaneous tissue and deep fascia

4.Mucocutaneous junctions

5. Breasts

Skin appendages include

Hairs

Nails

Sweat Glands

Sebaceous glands

Skin

Largest organ, protective barrier, sensory surface.

7 functions of the skin

Protection

Thermoregulation

Cutaneous Sensation

Vitamin D synthesis

Excretion and Absorption

Aids Locomotion

Contains nerve endings

Function of Hair

Aid in sensing, thermoregulation, and UV protection.

Types of hair

Vellus - short and thin

Terminal hair - long and thick

Sebaceous Glands

Produce sebum, lubricate skin and hair.

Skin Appendages

Structures like hair, nails, and glands.

Vellus Hair

Short, thin hair, often referred to as peach fuzz.

Subcutaneous Tissue

Layer beneath skin, provides insulation and support with blood vessels and nerves.

Mucocutaneous Junctions

Boundary where skin meets mucous membranes.

Epithelium changes to epidermis; muscle becomes skeletal.

Mammary Glands (breasts)

Mammary glands on thoracic wall, functional in females.

Blood vessels are supplied by

Cutaneous circulation.

Thermoregulation

Process of maintaining body temperature through sweat.

Eccrine Glands

Sweat glands all over body, regulate temperature.

Apocrine Glands

Sweat glands in specific areas, produce thicker sweat.

Alopecia Areata

Autoimmune condition causing hair loss in patches.

Onychomycosis

Fungal infection affecting nails, often invaded by skin fungi.

Bromhidrosis

Condition causing unpleasant body odor from sweat. Linked to hyperhidrosis

Melanoma

Dangerous skin cancer from uncontrolled melanocyte growth.

Terminal Hair

Thicker, longer hair found on scalp and body.

Hair Follicle

Skin sac from which hair grows.

Hair bulb

Located at follicle base; generates hair and inner root sheath.

Hair bulb contains

Dermal papilla (mesenchymal cells + capillary loop).

Nail composition

tightly packed, hard, keratinized epidermal cells

Major Glands on the skin

Sebaceous and Sweat glands

Sweat Glands types

Eccrine and Apocrine

Eccrine Sweat Secretion

Merocrine

Eccrine Sweat Glands features (4)

1. All over body

2. Open directly to skin

3. Watery Secretions

4. Role in thermoregulation

Sebum

Oily secretion from sebaceous glands, prevents drying.

Dermal Papilla

Contains mesenchymal cells and capillary loop.

Cytokines

Proteins involved in cell signaling and immune response.

Growth Factors

Proteins that stimulate cell growth and development.

Cutaneous Circulation

Blood flow in skin, important for thermoregulation. Complex array of channels that supply nutrients and oxygen to both the epidermis and dermis

Innervation

Distribution of nerves to specific body areas.

Nerve Endings

Sensory receptors for touch, temperature, and pain.