Ch. 5 Notes
A&P
Smart
Name _________________________
Date _________________________
Ch.5 Integumentary System
I. Introduction
 ______________________ = skin, and associated hairs, nails, and exocrine
glands.

 ______ of your total body weight.
 _____________organ in the body.
 only organ seen everyday.
 Problems in other systems can be predicted by observing changes in
____________, flexibility, __________________, or sensitivity of the skin.
 Has 2 major components:
1) ____________________________________
 Includes:
2) ____________________________________
 Includes: ___________, nails, _____________________________
all which start at the dermis and protrude through the epidermis to
the skin surface.
 Beneath the dermis, the loose connective tissue is called the
____________________________________.
 Also called the __________________________.
 It separates the integument from the _______________________
surrounding other ________________ such as muscles and bones.
1
 General Functions of the skin:
1. ____________________ – of underlying tissues
2. Excretion –
3. ____________________ – of body temp
4. Synthesis –
5. _________________ – of nutrients
6. Detection –
II. Epidermis

 __________________________ = what we call “skin cells”
 Thick skin covers ____________ & ___________ and is 5 skin layers thick.
 _________________ covers the rest of the body and is ___skin layers thick.
A. Layers of the Epidermis
o Stratum ________________________
 Innermost
o Stratum ________________________
o Stratum ________________________
o Stratum ________________________
o Stratum ________________________
 Outermost
1. Stratum Germinativum

 Forms ____________________________ that extend into the
______________. Help _________________ surface area.
2
 Ridges on soles and palms increase surface area to increase
________________ for better __________________.

 Fingerprints are ridge patterns which can be used to
_________________ an individual.
 ________________________ = germinative cells which
determine skin color.
 ________________________ = large germinative cells that
dominate this layer.
o Are __________________ whose divisions replace the
superficial keratinocytes, which are ________ or lost at
the epidermal surface.
 Merkel cells = ____________ sensitive specialized cells found
on skin surfaces ___________________ hair. They release
chemicals which stimulate nerve endings.
2. Stratum Spinosum

 Consists 8-10 layers of cells.
 Langerhans cells = stimulate _________________ against
microorganisms and superficial ______________________.
3. Stratum Granulosum

3
 Consists of 3-5 cell layers

 They begin to produce proteins _____________________ and
______________. Keratin is the basic component of ________
and ________.
 As keratin fibers are developing:
o The cells become ______________ & ______________.
o Cell membrane __________________ & becomes _____
___________________
o Nucleus and other organelles __________________ and
the cells ________.
4. Stratum Lucidum

 Cells are _________________, densely packed, and filled with
_______________.
5. Stratum Corneum

 15 - 30 layers thick
 The layer exposed to the skin’s surface die (become
________________), but remain tightly __________________.
They are always shed in ______________.
4
 It takes ___________________________ for a cell to move
from the germinativum layer to the stratum corneum. Dead
cells remain here for about ____________ before they are shed.

 Through ________________________________, you lose a
__________ of water from interstitial fluids each day.
 If the skin is _______________ and connections between
superficial & deeper layers are broken, this water will pocket
forming _________________.
 When the skin is submersed in fresh water, the skin cells swell
______ normal size.
 When it is submersed in salt water, the process is reversed, so
that the water moves from the cell into the salt water. This
_____________________ dehydration.
B. Skin Color
 Color is due to an interaction between
1.
2.
 Skin Pigmentation
1. _____________________
 ______________________ pigment that accumulates
in skin.
 Found in orange-colored vegetables.
 Converted to _______________ (aides vision, etc.).
5
2. _____________________

 Melanocytes
o Located in __________________________
o Produce melanin from aa. _____________________
o Melanin travels in vesicles called _____________________
from melanocytes to keratinocytes, which
____________________ colors the keratinocyte until the
melanosome is ___________________ by a lysosome.
o Whites:

o Blacks:
 The melanosomes are _______________ and the
transfer also occurs in the ______________________
making pigmentation __________________ and more
persistent.
o Melanin in keratinocytes protects skin from ____ radiation.
 Small amounts of UV radiation stimulates synthetic
activity in the epidermis, but can damage DNA
causing _____________________ and promoting
____________________ development.
 Melanosomes in the keratinocytes become
_____________________ & surrounds the nucleus to
________________ the DNA from the UV radiation.
6
 Melanin synthesis accelerates _______________,
peaking about ____ days after the initial exposure.
 ______ individual can suffer skin ________________
from overexposure, but those with _______________
skin color have better ________________ protection.
 Over time, ____________________ damage can lead
to ____________________ maintenance of the
dermis, which results in premature _______________
or development of _____________ in the germinative
cells or ______________________, due to
_________________________ damage of these cells.
o Albinos

o Freckles

o Liver spots

o Jaundice
7
 Liver can’t excrete _________ & yellowish pigments
accumulate in _____________ ____________. In
advanced stages, skin and eyes can turn ___________.
o Vitiligo
 Individuals __________ their melanocytes. Believe
to be due to _______________ defenses malfunction
and antibodies attack _______________ melanocytes.
o Moles
 Moles occur when ___________________________
grow in a ______________ instead of being spread
throughout the skin.
 Moles may _______________ after exposure to the
sun, during the teen years, and during pregnancy.
o Skin Tags
 _______________________ = small flap of tissue
that hangs off the skin by a connecting stalk.
 Skin tags are _________ dangerous.
 They are usually found on the __________, chest,
back, __________________, under the breasts, or in
the groin area.
 Skin tags appear most often in _________________,
especially with weight gain, and in elderly people.
o Birthmarks
 Are ______________________ on the skin that are
noticeable at birth, or shortly afterwards.
 ____________________________ - a red, pink or
purple blemish that is caused by abnormal blood
vessels under the skin.
8
 ____________________________ - are usually
brown and are caused by the clustering of pigment
cells.
 Dermal Circulation
o Blood cells contain the pigment _____________________.
o When attached to _____________, hemoglobin has a bright
______ color. This gives the dermis a _________________
which is most apparent in light colored individuals.
C. The Epidermis & Vitamin D
 UV radiation causes skin cells in the germinativum & spinosum to
convert a cholesterol steroid into _______________ which is used
by the ______________ in the synthesis of _________________.
 Calcitriol is needed for normal ________________ &
phosphorous _____________ by the small intestine.
III. Dermis
A. Two Layers:
1. Papillary Layer


2. Reticular Layer
 Lies _______________ to the ____________________ layer
 Dense meshwork of irregular connective tissue
 ________________ fibers of this layer extend into the papillary
layer as well as the ___________________ layer.
9
 ______________ organs of epidermal origin extend into the dermis.
 Nerve fibers are also in the ________________.
 Wrinkles & Stretch Marks
 Collagen fibers are strong and ___________ ______________,
but are easily _________ or twisted. Our skin remains flexible,
and somewhat elastic, but collagen fibers stop _____________
before tissue damage occurs.
 Elastin fibers allow ________________ and will recoil to their
original _____________.
 ___________ in the skin also helps maintain _______________
and resilience.
 Aging, hormones, and overexposure of UV radiation
permanently _____________ the amount of _____________ in
the dermis, producing _____________ and sagging skin.
 Substantial weight gain can exceed the elasticity limits of the
skin resulting in _________________________.
 ______________ is a derivative of _________________ which
increases _______________ blood flow to stimulate dermal
_____________. Therefore, the rate of wrinkle formation
decreases and existing wrinkles become _______________.
B. Dermal Circulation & Innervation
 Ulcer =
 _____________= may affect bedridden or immobile patients with
circulatory restriction, especially when splints, casts, or bedding
continuously presses against superficial blood vessels.
10
 Dermatitis =
 ____________________________ = due to contact with
strong chemical irritants producing a rash that may spread.
Ex:
 Eczema =
 Diaper rash = caused by a combination of _____________,
irritating chemicals from fecal or urinary _______________
and _______________________.
 Hives =
IV. Subcutaneous Layer
 Aka. _________________________
 Not actually part of the _______________________
 _____________________ the skin’s _________________ while allowing
independent movement

 Most infants and small children have “_____________________” for
reducing ___________________, serves as an ________________ reserve,
and a shock absorber for the tumbling.
 As we grow, subcutaneous fat distribution changes.
o Men => accumulates at the ___________, arms, ________________,
& over buttocks
11
o Women => accumulates at the _____________, buttocks, ________,
and thighs.
V. Accessory Structures
A. Hair Follicles and Hair
 Not on the sides and soles of the ___________, palms of __________,
the sides of __________ and toes, _____ and portions of the genitalia
 Around 5 million hairs on the body, 2% on your head.
 Hairs originate in complex organs called ________ ______________.
 Hair Production

 Hair Function
 _________________ hairs on your body
 100,000 which are on your ___________
 Protects scalp from _____, cushions blows to your head,
and insulates the ___________.
 Hairs of the ears, nostrils, & eyelashes

 Body Hairs
 ____________________________, surrounding their follicles,
provides early warning of _______________ injury.
 Have _______________________ whose contractions cause
the hairs to stand erect while in ________ or in the ________.
12
 Types of Hairs
 2 Major Types of Hairs
1) _____________________ = “peach fuzz” body hair
2) _____________________ = on/around head, eyes, etc.
 Hair Color
 Caused by the pigments of the ______________________
 Genetically determined, but can be effected by _____________
or the ____________________.
 Pigment production decreases with _____ & the color lightens,
turning _________
 Because hair is _________, color changes are ____________
 Hair Loss
 Avg. hair loss from head ___________________.
 Loss of __________________, usually something wrong.
 Male Pattern Baldness results from ______________ level
changes in blood, which causes ______________________
production to change to ______________________ production.
B. Glands in the Skin
 2 types: sebaceous and sweat glands
1. Sebaceous Glands (oil glands)
 _________________ = a waxy, oily substance secreted onto
hair follicles. It ______________ skin & hair & ____________
bacteria growth.
 Folliculitis =
 __________ = caused by blocked oil gland.
13
 Sex hormone concentration causes an increase in ________
__________________.
 Acne results from ______________ oil building up under a
clogged ______________ duct, encouraging bacterial infection.
2. Sweat Glands
 2 types: Apocrine and Merocrine
a. Apocrine glands
 Found in/around ______________, nipples & _________
 Produce a ________________, cloudy, and potentially
________________ secretion.

 Apocrine sweat is ________________ to bacteria, which
________________ odor
b. Merocrine Sweat Glands
 More ________________ and widely _______________
 ________________ than apocrine glands.
 Highest concentration on ___________ and __________
 Sweat is called _______________ _________________.
It is __________________, but contains electrolytes,
______________ ______________, and waste products.
 Function of sensible perspiration
1)
2) Excrete water, ___________________ & toxins
3) _________________ harmful chemicals and discourage
microbial ___________________ on skin.
14
3. Other Integumentary Glands
 __________________________
 A cluster of ______________ or sacs, of female
mammals, in which __________ is produced to feed their
young.
 __________________________

C. Nails
 Protect exposed __________ helping to limit their _______________
when they are subjected to mechanical ____________.

 Underlying blood vessels give it its ____________. The pale crescent
is due to the vessels being ______________ (or hidden).
 ___________ of the nail consists of __________, tightly compressed
cells packed with ____________.
 These cells can be affected by conditions altering body
__________________, so changes in the ______________,
structure of, or appearance of nails can assist in diagnosis.
 Ex: Nails may turn yellow in patients with chronic
respiratory disorders, thyroid gland disorders, or AIDS.
VI. Local Control of Integumentary Function
 Somewhat functionally ___________________.
 It often responds ________________________ to local influences without
the involvement of the nervous or endocrine system.
15
o Ex: when the skin is subjected to mechanical stresses,
__________________ stem cells divide more rapidly increasing the
tissue depth forming ________________.
A. Injury and Repair
 The relative speed & effectiveness of skin ____________ vary
according to the _____________________.
 4 Stages in regeneration of skin after injury:
1)
2) Blood ___________ & __________ forms restricting the entry of
microorganisms to the area. Germinativum cells ______________
down the _____________ of the wound. ____________________
cells remove debris & __________________ to the area increases.
3) A ____________ later the scab is _______________________ by
epidermal cells migrating over the meshwork produced by
__________________ activity. Phagocytic activity has almost
ended and the fibrin clot is __________________.
4) After several weeks, the scab has been __________, and the
epidermis is complete. Dermal fibroblasts continue to make
_____________________ which will gradually elevate the
overlying epidermis.
VII. Aging and Integumentary System
 Epidermis __________ due to declining germinitivum ________________,
which results in older people more prone to ________________ and skin
_________________.
 Langerhans cells __________________ reducing sensitivity.
16
 Vitamin D3 production ____________________.

 Glandular activity ___________________.

 Hair follicles _________ functioning or produce _________________ hairs.

 ______________________ level changes, changing _______ distribution, so
both sexes over _______ tend to look ____________.
 Skin repairs proceed slowly, taking _____________ as long as it used to.
17