objectives list functions of skin explain role of skin in temperature regulation describe layers...

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