The Integumentary System

1
The Integumentary System

• Ch. 5

2
Objectives

• Identify various parts of the integument
• Know the functions of the integumentary system
• Know the structural composition of hair and nails
• Understand how skin disorders like cancer and
  burns are classified and what occurs during these
  disorders

3
The Integumentary System

• Includes the skin (integument) and the accessory
  organs found within the skin

4
Skin Integumentary System

• Functions prevent dehydration, protect from
  injury, serve as defense against microorganisms,
  regulate body temperature, make vitamin D,
  provide sensation, nonverbal communication
• Structure
• Epidermis outer layer, stratified squamous
  epithelial cells, no blood vessels, specialized
  keratinocytes and melanocytes
• Dermis deeper layer, support tissues, fibers

5
Skin Integumentary System
6
Epidermis

• Keratinized stratified squamous epithelium
• Cell types
• Regenerative stem cells
• Keratinocytes
• Melanocytes
• Tactile cells
• Dendritic cells

7
Layers of the Epidermis

• From deep out
• Stratum basale
• Stratum spinosum
• Stratum granulosum
• Keratohyaline granules
• filaggrin
• Lamellated granules
• Stratum lucidum
• Thick skin only
• Stratum corneum

pgbeautygroomingscience.com
8
Skin Histology
nku.edu
9
Skin Color

• Melanin
• The more produced, the darker the color
• Hemoglobin
• Reddish pink skin tones
• Carotene
• Yellow hue to skin
• Concentrates in stratum corneum

10
Dermis

• Connective tissue layer deep to the epidermis
• Attached to the epidermis via dermal papillae
• Interlocking arrangement with epidermal ridges
• Two layers
• Papillary
• Areolar
• Reticular
• Dense irregular

11
Accessory Structures of Dermis

• Hair shaft, follicle
• Smooth muscle attached to hair follicle, raises
  hair to upright position
• Oil glands/sebaceous glands secretion moistens
  and softens skin

12
Accessory Structures of Dermis (cont.)

• Sweat glands secrete sweat, help in temperature
  regulation
• Apocrine and merocrine
• Blood vessels supply nutrients, remove waste,
  assist in temperature regulation
• Sensory nerve endings for heat, cold, touch,
  deep pressure, vibration

13
Dermis
healthguide.howstuffworks.com
14
Hypodermis

• Binds skin to underlying tissue
• Functions as padding and insulation
• Subcutaneous fat
• Readily absorbs drugs given by hypodermic
  injection
• Highly vascular

15
Hair

• Pili (sing. Pilus) are composed of hard, dead
  keratinized cells
• Grow from a follicle that is typically found in
  the dermis
• Hair divided into three zones
• Bulb which lies in the follicle
• Root
• Shaft

keratin.com
16
Nails

• Scale-like modifications of the epidermis
  (startum corneum)
• Dead cells full of parallel hard keratin

emedicinehealth.com
17
Skin Disorders

• Skin Cancer
• One of the most prevalent cancers
• UV radiation damages cells
• Three types
• Basal cell carcinoma
• Most common, stratum basale
• Squamous cell carcinoma
• Stratum spinosum
• Malignant melanoma
• Most deadly, melanocytes

metrohealth.org
18
Burns

• Classified based on depth of tissue involvement
• First degree
• Epidermis
• Red, slight swelling
• Second degree
• Epidermis and into part of the dermis
• Red to white, more painful
• Regeneration of epidermis possible
• Third degree
• Full-thickness, completely through dermis and
  beyond
• Tan to brown, danger of fluid loss and infection
• Generally require skin grafts to replace dermis
  and epidermis

burn-recovery.org