Chapter 6: Integumentary System

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Organs

Body structures composed of two or more different tissue types that perform specific functions

Accessory organs

Skin, hair, nails, glands

Skin

Integumentary system that acts as a barrier between internal and external environments

Layers:

• Epidermis

• Dermis

Epidermis

Thin, outer layer of stratified squamous epithelium

• Consists of 4 layers in most areas, BUT 5 in thicker areas (palms and soles)

Dermis

Thicker, inner layer of connective tissue containing blood vessels

• smooth muscles

• nervous tissue

• glands (oil & sweat)

Basement membrane

Separates epidermis from dermis

• anchors both layers together

Name the membrane of the skin

Cutaneous membrane

Name the layers of the skin

• Epidermis

• Dermis

Subcutaneous layer (Hypodermis)

Located beneath the skin

• Anchors the skin to deeper tissues

• Insulates

• Composed of areolar and adipose connective tissue

• Composed of blood vessels and provides blood supply to the skin ( nutrient and oxygen delivery)

What are the 4 layers of the epidermis in most areas?

Stratum Basale

Stratum Spinosum

Stratum Granulosum

Stratum Corneum

What are the 5 layers of the epidermis in thicker areas (palm and soles)

Stratum Basale

Stratum Spinosum

Stratum Granulosum

Stratum lucidum

Stratum Corneum

Avascular

Lacks blood cells

What are the functions of the epidermis?

Protects against:

• water loss

• chemicals

• injury

• microorganisms

Keratinization

Process of Keratinocytes hardening, dehydrating, and dying as they reach the surface '

What are the cells responsible for the ability of the epidermis to resist abrasion and reduce water loss?

Keratinocytes

In which layer of the epidermis are melanocytes located?

Stratum Basal Layer

Is it apocrine sweat glands that are more common?

No, its eccrine sweat glands

Are sebaceous glands merocrine?

No, they are holocrine and sweat glands are mercocrine