Functions of the Integumentary System

Question 1

• Protects deeper tissues from:

* Mechanical damage (bumps)

Answer 1

• Physical barrier contains keratin, which toughens cells
• Fat cells to cushion blows
• Contains both pressure and pain receptors, which alert the nervous system to possible damage

Question 2

Chemical damage (acids and bases)

Answer 2

• Has relatively impermeable keratinized cells

* Contains pain receptors, which alert the nervous system to possible damage

Question 3

Microbe damage

Answer 3

• Has an unbroken surface and “acid mantle” (skin secretions are acidic and thus inhibit microbes, such as bacteria)
• Phagocytes ingest foreign substances and pathogens, preventing them from penetrating into deeper body tissues

Question 4

Ultraviolet (UV) radiation (damaging effects of sunlight or tanning beds)

Answer 4

• Melanin produced by melanocytes offers protection from UV damage

Question 5

Thermal (heat or cold) damage

Answer 5

Contains heat/cold/pain receptors

Question 6

Desiccation (drying out)

Answer 6

Contains a water-resistant glycolipid and keratin

Question 7

Aids in body heat loss or heat retention (controlled by the nervous system)

Answer 7

• Heat loss: By activating sweat glands and by allowing blood to flush into skin capillary beds so that heat can radiate from the skin surface
• Heat retention: By not allowing blood to flush into skin capillary beds

Question 8

Aids in excretion of urea and uric acid

Answer 8

Contained in perspiration produced by sweat glands

Question 9

Synthesizes vitamin D

Answer 9

Modified cholesterol molecules in skin converted to vitamin D in the presence of sunlight