objectives list functions of skin explain role of skin in temperature regulation describe layers...
TRANSCRIPT
Objectives List functions of skin Explain role of skin in temperature regulation
Describe layers of skin and characteristics
Explain factors that affect skin color
Describe accessory organs of skin
Chapter 5: Integumentary System
Functions
Protection Temperature Regulation
Vitamin D Sensory Excretion
Epidermis
Dermis
HypodermisOr subcutaneous
Structure of the skin
Integumentary System Consists of skin and accessory organs
Skin is 2 regions: Dermis Epidermis
A fatty layer lies deep (hypodermis)
Hair Follicles Skin Glands Nails
Skin is the body’s outer covering and its largest organ.
Epidermis
Tissue type: Stratified Squamous Epithelium
Keratinocytes: make up 90% of cells in epidermis
Epidermis
No direct blood supply Nutrients must diffuse into the epidermis
Cells in the Epidermis
1. Keratinocytes – produce a protein called keratin
2. Melanocytes - make dark skin pigment melanin
3. Merkel cells – associated with sensory nerve endings
4. Langerhans cells – macrophage-like dendritic cells
Epidermis: most superficial
Stratum Corneum: Many layers of dead cells keratinocytes - keratin, Moisture lock
Stratum Lucidum:Stratum Granulosum:Statum Spinosum:Stratum Basale:
Desquamification: shedding of outermost layer of a tissueYour skin constantly sheds dead cells, about 30,000 to 40,000 every minute! That’s 9 pounds per year!
Stratum Corneum: Stratum Lucidum:
Protect from UV Thick layer Only in frequently used areas
Stratum Granulosum:Statum Spinosum:Stratum Basale:
Stratum Corneum: Stratum Lucidum:Stratum Granulosum:
Thin middle layer Layers of keratinocytes Initiate keratinization
Statum Spinosum:Stratum Basale:
Stratum Corneum: Stratum Lucidum:Stratum Granulosum:Statum Spinosum:
Cells interlock to support skin Resist tension Langerhans cells (found more here than other layers)
Stratum Basale:
Stratum Corneum: Stratum Lucidum:Stratum Granulosum:Statum Spinosum:Stratum Basale:
Single layer of cells Rest on basement membrane Cells divide continuously Youngest cells found here Melanocytes & Merkel cells here
Epithelium: layers (on left) and cell types (on right)
Review
1. The functions of the skin include all of the following except:
a. Taking in nutrientsb. Preventing entry of microorganismsc. Retarding water lossd. Regulating body temperature
Review
1. Which layer of the Integumentary System is the foundation for the skin?
a. Epidermisb. Hypodermisc. Dermisd. Stratum Corneum
Review
1. Which of the following is NOT considered an accessory organ of the Integumentary System?
a. nailsb. hairc. arteriesd. glands
Review
1. Which of the following cell types is responsible for sensory in the epidermis?
a. Langerhansb. Keratinocytesc. Melanocytesd. Merkel