The Integumentary
System: Chapter 5
Directions
To Manual
Words
that are underlined with three dots after them are hyperlinks. Also, pictures might by hyperlinks.
Structures
of the Skin
The
skin covers the whole body. It has
a surface area of about 1.8 square meters on an adult. The skin is sometimes called the cutaneous
membrane or
the integument. The skin is made up of two
regions. They are called the
epidermis and the dermis. The hypodermis is a subcutaneous tissue
found between the skin and any underlying structures.
Epidermis
It is
the outer and thinner region of the skin.
It is made up of stratified squamous epithelium divided into many
layers.
Dermis
The
dermis is thicker and deeper than the epidermis and it is made of dense
irregular connective tissue. The
upper layer has fingerlike projections called dermal papillae. They project into and anchor the
epidermis. This causes
ridges. They cause spiral and
concentric patterns which are fingerprints.
Ő
Hypodermis
This
is the subcutaneous tissue which lies below the dermis. It is made of loose connective tissue
including adipose which is fat. Fat
is an energy
storage form that can be called upon when necessary to supply the body with
molecules for cellular respiration.
Accessory
Structures of the Skin
Accessory
structures of the skin include hair, nails, and glands. Hair is found on all body parts
except the palms, soles, lips, nipples, and portions of the external
reproductive organs. They project
from hair follicles that are formed from epidermal calls. Nails grow from special epithelial
calls at the base of the nail in the region called the nail root. The pink color of nails is due to the
vascularized dermal tissue beneath the nail. The whitish color of the half-moonshaped base which is
called lunula. Glands are groups of cells
specialized to produce and secrete substance into ducts. There are three types of glands: sweat glands, sebaceous glands, and
mammary glands. Sweat glands are
present in all regions of the skin.
There are apocrine and eccrine glands. Apocrine opens to hair follicles, eccrine opens to the
surface of the skin. Sebaceous
glands are associated with the hair follicle. They secrete an oily substance called sebum. This lubricates the hair and skin and
helps waterproof them. Acne
vulgaris is the most common form of acne and it occurs mostly when you are a
teenager because of hormonal changes.
Mammary glands are located in the breast. A female has about 15 to 25 lobes. They secrete milk.
Disorders
of the Skin
There
are many disorders of the skin that are not life threatening but can be
annoying. This includes athletes
foot a fungal
infection normally in the foot area.
Impetigo
is a highly contagious disease occurring most often in young children. Psoriasis is a chronic condition which
could be hereditary where the skin develops pink or reddish patches covered by
scales. Another is dandruff which is a skin disorder
where the rate of keritinization is increased greatly. Lastly is urticaria which is hives.
Skin
Cancer
A
life threatening skin disorder is cancer.
It can either be melanoma or non-melanoma. Basal cell carcinoma is the most common type of skin cancer. It begins when ultraviolet radiation
causes epidermal basal cells to form a tumor, while at the same time
suppressing the immune systems ability to detect the tumor. Squamous cell carcinoma starts in the epidermis
proper. It is five times less
common than basal cell carcinoma.
It may spread to nearby organs and death only happens in about 1 percent
of cases. Melanoma
usually starts in the form of a mole.
It is most common in fair skinned people.
The
process for wound healing:
A.
A
deep wound ruptures blood vessels and blood flows out and fills the wound
B.
After
a blood clot forms, a protective scab develops
C.
Fibroblasts
and white blood cells migrate to the wound site
D.
new
epidermis forms and fibroblasts promote tissue regeneration
E.
Freshly
healed skin
Burns
First
degree burns: only epidermis is
affected. Redness and pain, no blistering
or swelling.
Second
Degree burns: Extends through
entire epidermis and part of the dermis.
Redness and pain, and also blistering.
Third
Degree Burns: Full thickness burns
and destroys the entire thickness of skin. Skin may be black, tan, white, or red.
Fourth
Degree Burns: burned down to the
bone. Most do not survive.
Rule
of nines: estimating the extent of
burns.
The
Effects of Aging
With
aging homeostasis adjustments to heat is limited due to few vasculature (fewer
blood vessels) and fewer sweat glands. The number of hair follicles also
decreases causing the hair to become extremely thin. As a person ages the number of melanocytes decreases. This
causes the hair to turn grey and the skin to become paler. Skin changes can
also be due to sun damage.
Safety
Instructions
To
keep your skin healthy you should try to avoid direct sunlight for many hours
or long periods of time. When you
are exposed to the sun you should use sunscreen or wear protective
clothing. The sun is the hottest
from 10 until 3.
Maintenance
Daily
you should wear lotion with spf in it.
You should also go yearly to get your skin checked for skin cancer. If you have any suspicious looking
spots or moles on your skin you should also get that checked out.
Automatic
Systems Check
The
bodies skin helps regulate water and does not let you lose too much or gain too
much.
Other
topics for maintenance
If
you absolutely need to get tan you should consider visiting your local Sunset
Tan and get spray tanned.
Troubleshooting
Problem: A strange looking mole.
Answer: Go see a doctor and get it checked out
Available
Options/Upgrades
To
enhance your skin color consider spray tanning, not tanning beds as they can help
in the progression and production of skin cancer. The only thing that could really go wrong is that you could
become orange is the person who sprays you isnŐt good and doesnŐt know how to
spray or sprays too much. SUNSET TANÉ