1. Chapter 5
Integumentary System

2. Integumentary System Consists of: Functions Skin Hair Nails Glands
Protection
Sensation
Temperature regulation
Vitamin D production
Excretion

3. Hypodermis Skin rests on this, but not a part
Consists of loose connective tissue
Types of cells
Fibroblasts
Adipose cells
Macrophages
Also called
Subcutaneous tissue
Superficial fascia

4. Skin Dermis Epidermis Structural strength Cleavage lines Two layers
Reticular
Papillary
Epidermis
Avascular
Cells
Layers or strata

6. Cleavage or Tension Lines
Elastin and collagen fibers oriented in some directions more than others
Important in surgery
If incision parallel to lines there is less gapping, faster healing, less scar tissue

7. Dermis and Epidermis

8. Epidermal Cells Cell types Desquamate: Older cells slough off
Keratinocytes: Produce keratin for strength
Melanocytes: Contribute to skin color
Langerhans’ cells: Part of the immune system
Merkel’s cells: Detect light touch and pressure
Desquamate: Older cells slough off
Keratinization: Cells die and produce outer layer that resists abrasion and forms permeability layer

9. Epidermal Strata Stratum Basale Stratum Spinosum Stratum Granulosum
Deepest portion of epidermis and single layer
High mitotic activity and cells become keratinized
Stratum Spinosum
Limited cell division
Stratum Granulosum
In superficial layers nucleus and other organelles degenerate and cell dies
Stratum Lucidum
Thin, clear zone
Stratum Corneum
Most superficial and consists of cornified cells

10. Epidermal Layers and Keratinization

12. Thick and Thin Skin Thick skin Thin skin Has all 5 epithelial strata
Found in areas subject to pressure or friction
Palms of hands, fingertips, soles of feet
Thin skin
More flexible than thick skin
Covers rest of body

13. Skin Color Determined by 3 factors Pigments
Melanin: Provides for protection against UV light
Albinism: Deficiency or absence of pigment
Carotene: Yellow pigment
Blood circulating through the skin
Imparts reddish hue and increases during blushing, anger, inflammation
Cyanosis: Blue color caused by decrease in blood oxygen content
Thickness of stratum corneum

15. Accessory Skin Structures
Hair
Found everywhere on human body except palms, soles, lips, nipples, parts of external genitalia, and distal segments of fingers and toes
Glands
Sebaceous or oil glands
Sudoriferous or sweat glands
Ceruminous glands
Mammary glands
Nails

16. Hair Structure Composed of shaft and root Has 3 concentric layers
Shaft protrudes above skin surface
Root located below surface and base forms the hair bulb
Has 3 concentric layers
Medulla: Central axis
Cortex: Forms bulk of hair
Cuticle: Forms hair surface

19. Hair Growth, Color, and Muscles
Cycles
Growth and resting
Permanent hair loss
Pattern balding most common
Hair Color
Caused by varying amounts and types of melanin
Muscles
Arrector pili: Muscle contraction causes hair to “stand on end”

20. Oil and Sweat Glands Sebaceous glands Sudoriferous glands
Produce sebum
Oils hair and skin surface
Sudoriferous glands
Merocrine or eccrine
Most common
Numerous in palms and soles
Apocrine
Found in axillae, genitalia, around anus

23. Nails Anatomy Growth Nail root proximally
Nail body distally: Eponychium or cuticle
Growth
Grow continuously unlike hair

26. Burns Classifications Skin Grafts First-degree Second-degree
Third-degree
Skin Grafts
Split skin
Artificial skin
Cadavers or pigs

27. The Rule of Nines

28. Aging Effects Skin more easily damaged Skin becomes drier
Functioning melanocytes decrease or increase as with age spots
Sunlight ages skin more rapidly

29. Clinical Disorders Bacterial infections Viral Infections
Acne
Viral Infections
Chicken pox, German measles, cold sores
Decubitus ulcers or bedsores
Ischemia and necrosis
Cancer
Basal cell carcinoma
Squamous cell carcinoma
Malignant melanoma