Integumentary System

1
The Integumentary System
The skin is the bodys largest organ
Each square inch of human skin consists of twenty
feet of blood vessels.
2
The Integumentary System
3
Its the Skin Were In! The epidermis is the
topmost layer. It helps to prevent evaporation of
water from the body and to protect the internal
layers from harm. The dermis is the middle
layer. It contains the blood vessels, nerves,
hair roots, and sweat glands. The subcutaneous
tissue is the deepest layer. It contains fats and
connective tissue along with large blood vessels
and nerves.
Why do fingers and toes wrinkle in the bathtub?
4
The Integumentary System
5
Its a Hairy Situation! Hair color is determined
by the amount and type of melanin
present. Melanocytes become less active with
age. Gray hair is a mixture of pigmented and
non-pigmented hairs. Red hair results from a
modified type of melanin that contains iron. The
shape of the hair shaft determines texture. Round
shaft straight hair Oval shaft wavy hair Flat
shafts curly or kinky hair Alopecia is the term
for hair loss.
Why do we get goose bumps when it is cold?
Why do men have to shave everyday?
6
The Integumentary System
7
Dont sweat it! Sebaceous glands or oil glands
secrete the sebum an oily product. Sebum is
usually secreted into a hair follicle. Sebum is a
natural skin cream it helps hair from becoming
brittle, prevents excessive evaporation of water
from the skin, keeps the skin soft and contains a
bactericidal agent that inhibits the growth of
certain bacteria. Eccrine glands are the most
common sweat gland . They produce sweat, a watery
mixture of salts, antibodies and metabolic
wastes. Sweat prevents overheating of the body
and thus helps regulate body temperature.
How much do we sweat in a day?
8
The Integumentary System
9
Red, Yellow, Black or White The red and yellow
hues of the skin are due to hemoglobin in the red
blood cells, which pass through the capillaries
beneath the epidermis, and carotene (yellowish
pigment), which accumulates in fat cells found in
the dermis and hypodermis
 The brown in skin color is due to melanin, which
is produced in the skin itself in cells called
melanocytes. These cells are located in the
epidermis. Melanin protects the chromosomes of
mitotically active basal cells against
light-induced damage
10
Malfunctioning Melanocytes

• Albinism melanocytes completely fail to secret
  melanin. Hair, skin, and iris are white.
• Vitiligo loss of pigment in certain areas of
  the skin producing white patches.
• Freckles and moles are formed when melanin
  becomes concentrated in local areas.
• Malignant melanoma a cancerous change in a mole
  that may metastasize (spread) rapidly and is most
  difficult to treat. Exposure to sunlight
  increases risk.

What can cause a baby to turn orange?
11
The Integumentary System
12
Guiness Book of Records
13
Functions of the Skin

• Protection
• Barrier Function
• Resistance to wear and tear

• Vitamin D Production
• Protection from UV light
• Sensations
• Temperature regulation

Red with embarrassment! White from
fright!
14

• You have approximately 19,000,000 skin cells on
  every square inch of your body.
• Humans shed about 600,000 particles of skin every
  hour about 1.5 pounds a year.
• House dust is mainly skin flakes!
• Skin weighs about 2.5 kilograms - the largest
  organ in the body.
• What hurts if you pull it, but doesn't hurt if
  you cut it? Your hair, of course!
• Skin is elastic - it springs back into shape when
  stretched. Some medicines (estrogen, nicotine)
  can pass through the skin, but others cannot
  (insulin). This is because only fat-soluble
  substances can enter the skin, not water-soluble
  ones.
• Skin grows faster than any other organ and
  continues to grow throughout our lives.