1. The Integumentary System
Section 32.1
The Integumentary System

2. 32.1 The Integumentary System
The Structure of the Skin
Multilayered organ
Covers and protects the body.

3. The Epidermis Outer, superficial layer of skin
The outer layers contain keratin
Waterproofs
Protects cells and tissues that lie underneath.

4. The Epidermis, continued…
Inner layer contains cells that continually divide to replace cells that are lost or die.
Some cells in the inner layer provide protection from harmful UV radiation by making a pigment called melanin.

5. The Dermis connective tissue nerve cells muscle fibers
Directly beneath the epidermis is the dermis.
Consists of:
connective tissue
nerve cells
muscle fibers
Sweat, oil glands
hair follicles
Below is the subcutaneous layer, a layer of connective tissue that stores fat and helps the body retain heat.

6. Hair and Nails Both contain keratin, develop from epithelial cells.
Grow out of narrow cavities in the dermis called hair follicles.
Follicles usually have sebaceous glands that lubricate the skin and hair.

7. Functions of the Integumentary System
Temperature regulation
Vitamin production
Protection and senses

8. Damage to the Skin Skin has remarkable abilities to repair itself.
Without a repair mechanism, the body would be subject to invasion by microbes through breaks in the skin.

9. Cuts and Scrapes
Cells deep in the epidermis divide and replace the lost or injured cells.
When the injury is deep, blood vessels might be injured, resulting in bleeding.
Infection-fighting white blood cells will help get rid of any bacteria that might have entered the wound.

11. Effects of the Sun and Burns
Burns caused by:
Sun
Heat
Chemicals
Classified according to their severity.

13. Skin Cancer
UV radiation can damage the DNA in skin cells, causing those cells to grow and divide uncontrollably.
Two main categories of skin cancer: melanoma and nonmelanoma.

14. 32.1 Formative Questions What protective protein is contained in the
outer layers of epidermal cells?
collagen
keratin
fibrinogen
melanin

15. 32.1 Formative Questions
How do cells in the skin protect the skin from
ultraviolet radiation?
They secrete oils.
They store cutin.
They absorb calcium.
They produce melanin.

16. 32.1 Formative Questions Where are sebaceous glands located? dermis
hair follicles
sweat pores
subcutaneous tissue

17. 32.1 Formative Questions For which type of burn is there usually
no pain?
first-degree
second-degree
third-degree

18. 32.1 Formative Questions Why is exposure to ultraviolet radiation a
significant risk factor for the development
of skin cancer?
It damages the DNA in skin cells.
It causes excess vitamin D production.
It mutates melanin molecules in the skin.
It causes irregular freckles and moles to
appear.

19. What might result from a blocked sebaceous gland? acne sweat baldness
Chapter 32
Integumentary, Skeletal, and Muscular Systems
Chapter Assessment Questions
What might result
from a blocked
sebaceous gland?
acne
sweat
baldness
ingrown hair

20. Which structure causes goose bumps?
Chapter 32
Integumentary, Skeletal, and Muscular Systems
Chapter Assessment Questions
Which structure causes goose bumps?
nerves
fat
sweat glands
muscles

21. Describe how a cut on the skin heals.
Chapter 32
Integumentary, Skeletal, and Muscular Systems
Chapter Assessment Questions
Describe how a cut on the skin heals.
Answer: Blood flows out of the skin and
forms a clot and scab. Under the
scab, cells multiply to fill the wound.
Infection-fighting white blood cells
get rid of bacteria.

22. What is this bump in the skin? a mole a wart a goosebump
Chapter 32
Integumentary, Skeletal, and Muscular Systems
Standardized Test Practice
What is this bump
in the skin?
a mole
a wart
a goosebump
an acne pimple

23. What protein do hair and nails contain?
Chapter 32
Integumentary, Skeletal, and Muscular Systems
Standardized Test Practice
What protein do hair and nails contain?
chitin
cutin
keratin
myosin