Integumentary System A&P

SLIDESMANIA.COM

The Integumentary System

• Derives its name from the Latin word

integumentum, which means to cover

• Skin is the largest organ system

– average adult wears 8-10 pounds of skin and

covers an area of 22 square feet

3

SLIDESMANIA.COM

Functions of the Integumentary

System

•Protection

covers the body and acts as a physical barrier

•Body Temperature Maintenance

contains sweat glands; secretes fluid (perspiration)

•Excretion

Flush waste with perspiration

•Perception of stimuli

contains large number of nerve endings

•Synthesizes vitamin D

SLIDESMANIA.COM

The Integumentary System

• Is composed of the following:

– skin which is composed of three layers:

• epidermis
• dermis
• hypodermis (subcutaneous layer)

– accessory structures which include:

• hair
• nails
• glands

5

SLIDESMANIA.COM

The Integumentary System

Layers of the Skin

6

SLIDESMANIA.COM

The Epidermis

• Is the thin, outermost layer of the skin and divided

into layers of epithelial tissue

• is divided into 4 different layers (5 in some areas)
• Provides the first barrier
• Contains several sub layers called strata (stratum)

Keratin: prevents body fluids from evaporating

• Soft keratin is the primary substance of the

epidermis; Hard keratin is found in hair and nails

Melanocytes: produce dark brown-to-black pigments called
melanin (helps protect skin against UV rays)

Most household dust is dead skin cells.
7

SLIDESMANIA.COM

The Epidermis

• Is composed of layers of thin, flattened cells

which fit closely together and are able to
with stand constant use and friction

• Has the ability to produce vitamin D

when exposed to UV sun radiation

9

SLIDESMANIA.COM

SLIDESMANIA.COM

The Dermis

• Is called the true skin or corium
• Is the layer beneath the epidermis
• made up of

– connective tissue

• collagen

– blood vessels
– nerves
– sebaceous gland
– sudoriferous glands
– hair follicles

10

SLIDESMANIA.COM

Subcutaneous Layer

• Lies beneath the dermis
• Is also known as the

hypodermic layer,

• Consists of loose connective tissue and

adipose tissue (fat) which insulates the body

• Anchors the skin to the underlying muscle