The document summarizes the key components and functions of the integumentary system. It discusses the epidermis and dermis layers of the skin, how they provide protection and regulate temperature and moisture. It describes hair follicles, glands, nails and pigmentation. The document also addresses how skin responds to injury through regeneration and how it ages over time, with thinning and slower repair.
2. Learning Objectives
• List the components of the integumentary system,
including their physical relationships.
• Specify the functions of the integumentary system.
• Describe the main features and functions of the
epidermis and dermis.
• Discuss individual and racial differences in skin.
• Discuss the effects of UV light on the epidermis.
• Explain the structure and function of the various
accessory organs of the skin.
• Explain how the skin responds to injury and aging.
3. • Cutaneous membrane
• Epidermis
• Dermis
• Accessory structures
• Subcutaneous layer
The integumentary system consists of
7. • The epidermis is composed of layers of
keratinocytes
• Thin skin = four layers (strata)
• Thick skin = five layers
Figure 5.2 Thin Skin and Thick Skin
Figure 5.2
8. • Provides mechanical protection
• Prevents fluid loss
• Keeps microorganisms from invading the body
The epidermis
9. • Stratum germinativum
• Stratum spinosum
• Stratum granulosum
• Stratum lucidum
• Stratum corneum
Layers of the epidermis:
11. • Cells accumulate keratin and eventually are shed
• Epidermal ridges are interlocked with dermal
papillae
• Fingerprints
• Improve gripping ability
• Langerhans cells (immunity) in s. spinosum
• Merkel cells (sensitivity) in s. germinativum
Epidermal characteristics:
13. • Blood supply
• Carotene and melanin
• Melanocytes produce melanin and protect
from UV radiation
• Epidermal pigmentation
• Interrupted blood supply leads to cyanosis
Skin color depends on
24. • Originate in hair follicle
• Composed of root and shaft
• Root base (hair papilla) surrounded by hair bulb
and root hair plexus
• Hairs have soft medulla and hard cortex
• Cuticle = superficial dead protective layer
Hairs
26. • Vellus hairs (peach fuzz)
• Terminal hairs ( heavy)
• Club hair (cessation of growth)
• Shed and grow according to hair growth cycle
Arrector pili muscle attaches to hair
Hair types
33. • Mammary glands
• Structurally similar to apocrine sweat glands
• Ceruminous glands
• In ear, produce waxy cerumen
Other glands
34. • Nail body covers the nail bed
• Nail production occurs at the nail root
• Eponychium (cuticle) overlies root
• Free edge of nail extends over hyponychium
Nails
41. • The components of the integumentary system,
including their physical relationships.
• The functions of the integumentary system.
• The main features and functions of the epidermis
and dermis.
• Individual and racial differences in skin.
• The effects of UV light on the epidermis.
• The structure and function of the various
accessory organs of the skin.
• How the skin responds to aging.
You should now be familiar with: