3. Integument

Integumentary System Overview

Chapter Reading List (Page 1)

• Sections Covered:

  • Sec. 5.1 – Structure & Function

  • Sec. 5.2 – Epidermis

  • Sec. 5.3 – Dermis

  • Sec. 5.4 – Subcutaneous Layer

  • Sec. 5.5 – Integrated Structures

  • Sec. 5.7 – Aging

Embryonic Development (Page 2)

• Key Structures:

  • Caudal end, Cephalic end, Connecting stalk

  • Amniotic cavity, Amnion, Primitive streak

  • Ectoderm, Mesoderm, Endoderm

• Developmental Timeline:

  • 7-8 weeks: Developing epidermis and dermis

  • 11-12 weeks: Formation of key structures

  • Birth: Fully developed integumentary system

Skin Structure (Page 3)

• Components of the Integumentary System:

  • Hair shaft, Sweat pore, Epidermis

  • Dermal papilla, Papillary layer, Reticular layer

  • Sebaceous (oil) gland, Sweat gland duct

  • Subcutaneous layer, Adipose connective tissue

• Sensory Structures:

  • Tactile receptors, Sensory nerve fibers

Epidermis Layers (Page 4)

• Layers of the Epidermis:

  • Stratum corneum (dead keratinocytes)

  • Stratum lucidum

  • Stratum granulosum

  • Stratum spinosum (living keratinocytes)

  • Stratum basale (contains melanocytes and dendritic cells)

• Supporting Structures:

  • Basement membrane, Dermis

Nail Structure (Page 5)

• Components of Nails:

  • Nail fold, Nail body, Free edge, Eponychium (cuticle)

  • Nail matrix, Lunula, Nail bed

• Hair Structure:

  • Hair follicle, Hair bulb, Arrector pili muscle

Dermal Layers (Page 6)

• Dermis Composition:

  • Epidermal ridges, Dermal papillae

  • Papillary layer, Reticular layer

• Vascular Structures:

  • Arteries, Veins

• Connective Tissue Types:

  • Areolar connective tissue, Adipose connective tissue

Surgical Considerations (Page 7)

• Incision Techniques:

  • Incisions perpendicular to cleavage lines may gape and delay healing.

  • Incisions parallel to cleavage lines are more likely to heal quickly.

Sweat Glands (Page 8 & 9)

• Types of Sweat Glands:

  • Merocrine sweat glands: Ducts and pores

  • Apocrine sweat glands: Associated with hair follicles

  • Sebaceous glands: Oil production

• Microscopic Views:

  • Various magnifications of sweat glands and hair follicles

Skin Cancer Types (Page 10)

• Common Skin Cancers:

  • Malignant Melanoma

  • Basal Cell Carcinoma

  • Squamous Cell Carcinoma

Tissue Changes (Page 11)

• Types of Tissue Changes:

  • Atrophy, Hypertrophy, Hyperplasia

  • Metaplasia, Dysplasia

Risk Assessment (Page 13)

• Degree of Risk for Skin Conditions:

  • Normal, Precancer/IEN/Dysplasia

  • Initiated, Mild, Moderate, Severe (CIS - Cancer)

• Epithelial Changes:

  • Squamous epithelium, Superficial zone, Midzone, Basal layer

This note summarizes the key concepts and structures of the integumentary system, including its development, anatomy, and clinical c