The integumentary system consists of the skin and its accessory structures. The skin protects the body from damage, regulates temperature and fluid balance, and produces vitamins. It is composed of three layers - the epidermis, dermis and hypodermis. The epidermis is made of keratinized stratified squamous epithelial tissue. The dermis contains blood vessels, hair follicles, and glands. The hypodermis anchors the skin and stores fat. The skin contains glands that secrete sweat, oil and wax to regulate body functions. Accessory structures include hair, nails and nerves that provide sensory information.
5. •Helps the body maintain
homeostasis by regulating
temperature, retaining
body fluids, and
eliminating wastes.
•Insulates and cushions
deeper organs
7. Skin
•The largest organ of the
body
•1.5 – 2 sq meters
•4 kilograms, 7-15% of
total body weight
8. Skin
•Varies in thickness from
1/50 inch (0.5 mm) in the
eyelids to 1/4 inch (6.3
mm) in the soles of the
feet
9. •Changes in the skin often
indicate the presence of
other body system
disorders including
anemia, respiratory
disorders, liver disorders,
cancer, and shock
10. •Each inch of skin contains
15 ft of blood vessels
•The body sloughs off
about 500 million cells a
day; 1 ½ pounds per year
11. •The top layer is full of
keratin to prevent water
loss
•The rich capillary network
and sweat glands help
regulate heat loss from
surface
12. •It is a mini-excretory
system- loses urea, water
and salts
•Cutaneous sensory
receptors provide info
about the environment
48. Hair and Hair Follicles
•Skin has hair in all areas
except the soles of the
feet and palms of the
hands
49. Hair and Hair Follicles
•Composed of keratin and
proteins; also dead
epidermal cells
50. Hair and Hair Follicles
•Hair serves to block
foreign particles from
entering the body through
structures such as the
nose and eyes
51. Hair and Hair Follicles
•The visible portion is
called the shaft
•The hair follicle is the root
with its covering
–Anagen: growing follicle
–Telogen: resting follicle
59. Sebaceous (Oil) glands
•Secretory in dermis- open
into hair shafts
•Acne- bacterial
inflammation of glands
–Secretions stimulated by
hormones at puberty
62. Sudoriferous glands
•Apocrine (sweat) glands-
secrete at hair follicle and
active at puberty
–In dermis with ducts that
open into hair follicles
–Axilla –Perianal
–Areole -Periumbilical
64. Sudoriferous glands
–Also consists of ducts
and secretory coils, but
these glands are larger
than eccrine glands and
open onto hair follicles.
65. Eccrine (sweat glands)
Most areas of the body
In dermis with ducts to
surface
Regulates body temp w/
perspiration
(500 mL p/day)
66. •Modified sweat glands
•Located in auditory canal
•Cerumen- contains
secretions of oil and wax
glands; barrier for entrance
of foreign bodies
•Impacted cerumen may
reduce hearing