the integumentary system section 32.1. the structure of the skin multilayered organ covers and...
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The Integumentary System
Section 32.1
The Structure of the Skin Multilayered organ Covers and protects the body.
32.1 The Integumentary System
The EpidermisOuter, superficial layer of skin The outer layers contain keratin
Waterproofs Protects cells and tissues that lie
underneath.
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.
The DermisDirectly beneath the epidermis is the dermis.Consists of:
connective tissuenerve cellsmuscle fibersSweat, oil glandshair follicles
Below is the subcutaneous layer, a layer of connective tissue that stores fat and helps the body retain heat.
Hair and NailsBoth 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.
Functions of the Integumentary SystemTemperature regulationVitamin productionProtection and senses
Damage to the SkinSkin has remarkable abilities to repair
itself.Without a repair mechanism, the body
would be subject to invasion by microbes through breaks in the skin.
Cuts and ScrapesCells 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.
Effects of the Sun and Burns
Burns caused by:SunHeatChemicals
Classified according to their severity.
Skin CancerUV 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.
What protective protein is contained in the outer layers of epidermal cells?
A. collagenB. keratinC. fibrinogenD. melanin
32.1 Formative Questions
How do cells in the skin protect the skin from ultraviolet radiation?
A. They secrete oils.B. They store cutin.C. They absorb calcium.D. They produce melanin.
32.1 Formative Questions
Where are sebaceous glands located?
A. dermisB. hair folliclesC. sweat poresD. subcutaneous tissue
32.1 Formative Questions
For which type of burn is there usually no pain?
A. first-degreeB. second-degreeC. third-degree
32.1 Formative Questions
Why is exposure to ultraviolet radiation a significant risk factor for the development of skin cancer?
A. It damages the DNA in skin cells.B. It causes excess vitamin D production.C. It mutates melanin molecules in the skin.
D. It causes irregular freckles and moles toappear.
32.1 Formative Questions
What might result from a blocked sebaceous gland?
A. acneB. sweatC. baldnessD. ingrown hair
Integumentary, Skeletal, and Muscular Systems
Chapter Assessment Questions
Chapter 32
Which structure causes goose bumps?
A. nervesB. fatC. sweat glandsD. muscles
Integumentary, Skeletal, and Muscular Systems
Chapter Assessment Questions
Chapter 32
Describe how a cut on the skin heals.
Integumentary, Skeletal, and Muscular Systems
Answer: Blood flows out of the skin andforms a clot and scab. Under the scab, cells multiply to fill the wound. Infection-fighting white blood cells get rid of bacteria.
Chapter Assessment Questions
Chapter 32
What is this bump in the skin?
A. a moleB. a wartC. a goosebumpD. an acne pimple
Integumentary, Skeletal, and Muscular Systems
Standardized Test Practice
Chapter 32
What protein do hair and nails contain?
A. chitinB. cutinC. keratinD. myosin
Integumentary, Skeletal, and Muscular Systems
Standardized Test Practice
Chapter 32