Download 2. Regulation of body temperature - Belle Vernon Area School District

The Integumentary System
I. The Integumentary System - Epidermis, Dermis, Hypodermis
Major functions of the skin
1. Protection –
2. Regulation of body temperature –
3. Sensation –
4. Excretion of waste –
5. Vitamin D Production - when exposed to
helps with the absorption of calcium (bone growth).
,
II. Hypodermis
A. Lies
to the skin,
but is not apart of the layers
of skin.
B. Attached to underlying
bone & muscle.
C. Supplied with blood &
nerve.
D. Composed of
1.
2.
E. Stores half of your body fat.
1.
2.
The Skin
Made up of two parts.
1.
2.
– structure & strength
– prevent water loss & abrasion
II. Dermis
A. Composed of
contain a large supply
that
1. Dense collagenous
connective tissue.
2.
B.
– fibers are
arranged in a parallel direction for
greater resistance to stretching.
1.
– cut across the tensions
lines, more scare tissue.
2.
(striae) –
overstretching of the dermis.
C. Holds the accessory organs of
the integumentary system.
D. Divided into
areas
1. Papillary region
a. upper part of dermis, contains
.
b.
the lower part of the
, removal of
wastes, and temperature regulation.
c.
– projections upward
1
the connection between the 2 areas.
d.
– extended papillae into the epidermis & effects the
contour to form friction ridges, help the hand & foot grasp by
increasing friction.
2.
Deeper thicker area.
a. Composed of dense
irregular tissue.
b. Strengthens,
extensibility, & elasticity
by using protein fibers,
elastic, collagenous
fibers.
c. Wrinkles that
accompany &
are a result of a change
in the production or
quality of these protein.
III. Epidermis – 40-56 days for cells to be replaced
•Region of stratified squamous epithelium that is continuously replaced.
•Water Proof.
•Protective wrap around the body.
A. Layers(strata) of the Epidermis.
1.
deepest
1 layer of columnar cells
lots of nourishment
2.
multiple layer of cuboidal cells
Nuclei are pyknosis state of death
3.
3-5 layers of partially flatten cells that
contain granule, granules contain protein
(keratin)
present only in the thick skin of the palms
and soles.
3-4 rows of flatten dead transparent
“ghost” cells
4.
-
5.
-
Most superficial layer 25-50 rows of
flatten, dead cells - Wear & Tear
Joined by desmosomes, that eventually
breaks off and the skin falls off.
The Epidermis
B. Problems
1.
2.
3.
C. Skin color of the epidermis
1. Determined by melanocytes
a. Cells that lie between cells on the stratum
basale and produce melanin (pigment).
b. The golgi apparatus packages the melanin in
vesicles called melanosomes.
c. The packages move out of the cells to neighboring
cells and between them.
d. All humans have the about the same amount of
melanocyte, what causes differences in skin color?
e. Amount of melanin produced, causes of skin
color UV light triggers melanocyte to produce
melanin - tan
f. What benefit is provided by the production of
melanin?
g. Protects the body from harmful UV light.
d. Disorders of skin pigments
1.
2.
3.
– lack
of pigment
–
bluish skin
pigment
–
disorders of blood
vessels at birth.
IV. Accessory Organs
Organs located within the dermis.
Provide a role in protection,
communication, & excretion
A. Hair
1. Parts of hair
a.
– extends
through the epidermis.
b.
– below the
epidermis
c.
– base of root
d.
part
– hard outer
e.
part
– soft inner
f.
– outermost
covering
2. Cycles of hair
a.
b.
ex
eyelashes - grows
for
days, rests for
days.
scalp – grows for
years & rest for
.
B.
- Oil glands
(sebum)
-Occasionally they can be blocked
by dirt or dead cells.
-Become plugged or swollen –
blackhead
C. Sweat Glands
- Function through
out life, watery substance Sudoriferous - During puberty in
response to sex hormones
Proteins, which promote the
growth of bacteria, which
produce odoriferous materials
(armpits, & groin)
D. Receptors -
Accessory Organs
E. Nails -
Nails
flap of stratum corneum that overlies the proximal
edge of the nail
active stratum basale - nail matrix
light color crescent - sign of calcium deficiency
V. Homeostasis - Temperature Regulation
Good health - 37C +/- 1C
Proper function of enzymes
Movement of molecules
Chemical reactions
A.
Integumentary System helps to Maintain Body Temperature
Hot
Receptors in the skin
external
temperature which relay’s information to the brain.
Brain
Sweat glands to secretion
Blood vessels dilate or relax which
flow to the skin
blood
Carries
heat to the skin which is removed
from the body by evaporation.
Breathe
to exhale heat
Heart beats
to move more blood to the skin to
remove heat faster.
Cold
Goose bumps, arrector muscles contract
Skeletal muscle
slightly
Blood vessels
slightly
therefore
volume of warm blood to the skin,
reducing heat lose by the skin
Temperature Regulation
B. Skin Repair
Skin damage
Bleeding
- increase blood flow to damage area.
1. Remove
2. Promote
- clotting, scabs, temporary
barrier.
a. minor cut are produced
and migrate there.
b. Major - large number of
are present - scar (
)
Skin Repair
–new cells are the
same as the ones lost.
– new tissue
develops leaving a scar and has
los some function.
– do not divide after
growth stops, but can grow if
there is an injury.
– little or no dividing
ability.
- fibers to stop the
bleeding
– a dried clot
– revascularize area
under the scab (small wounds).
– (large wounds)
Skin Repair
VI. Skin Disease
A.
B.
C.
- Pimples
- Bacteria infection of a hair follicle -
abscess
Can spread to other tissue if not treated with
antibiotics.
- Metabolic disease because it effects a
metabolic balance that the cells must maintain.
Fatal - 50% or more is burned
3 types
– epidermis (
heal)
week to heal)
- epidermis & dermis (
weeks to
- completely damage in the
epidermis, dermis, & hypodermis, including all
accessory organs.
Cannot regenerate itself - grafting.
Burns, Partial & full –thickness
burns
D.
- Fungus athletes foot, jock itch.
E.
- Virus
F.
Disease from the formation
of a groups of cells with
NO function.
(non
invasive) freckles, moles
- cancer
G.
- Virus
- Contagious
-Reoccurring
outbreaks
H.
I.
4%
- Shingles
-Similar to herpes
-forms from chicken pox
-common in people over 50
- along a nerve usually in trunk
region
-Congenital disease - 3% -Small round skin elevation that
are covered with flaky skin
- Flare Ups
J.
- Infestation of
parasites
- lice, tick, crabs, spiders, insects
K.
- Inflammation of the
dermis
- redness, swelling, vesicles
- secondary infections - bacteria
L. Skin Cancer
Too
may
overwhelm the function of
melanin resulting in sunburn
or mutation in
which may lead to skin
cancer.
a.
carcinoma–
invasive cancer.
 Common in fair skin
individuals.
 Lesions that grow
rapidly ½ cm per
week.
 Red hard nodules
break opening after
forming.
 Treated by surgical
removal or X-ray
radiation.
b.
carcinoma

Tumors arise from the
cells from the
layer.

Grows slowly 1 -2
cm/yr.

Red waxy nodules in
the skin.

May cause lesion in
organs under the skin
if left untreated.

Excision is the
treatment.
c.
life threatening.
- Most
Tumor arises from
melanocyte in the basal
layer.
May appear to be
discolored, tender, or a
small nodule.
Starts as a small mole
that bleeds easily to
injury.
Spreads quickly to
nearby lymphs nodes
then vital organs
4,000 die each year
 Since 1973 there has
been an average of a 4% increase in cases
per year
 30,000 new cases a
year

Treatment is only effective if
the cancer is detected early widespread X-ray radiation
Malignant Melanoma
IX. Determining Your Skin Surface
Area
[(height in inches x weight in lbs)/3131].5
Average is 2m2
Your answer X 10.7639104 ft2
Source: Mosteller 1987