Transcript Document

Unit 3 (Chapter 5) - The
Integumentary System
and Body Membranes
Presented by Dawn Duran, PT,
MHS,CSCS
Adjunct Professor, Kaplan University
Types of Membranes
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Epithelial membranes - Epithelial membranes are composed of
epithelial tissue and an underlying layer of specialized connective tissue
called the basement membrane.
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Cutaneous membranes
Mucous membranes
Serous membranes
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Pleura
Pericardium
Peritoneum
Connective Tissue Membranes
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Synovial tissue membranes
CLASSIFICATION OF BODY
MEMBRANES
 Epithelial
membranes
 The cutaneous membrane refers to
the skin, which is the primary organ
of the integumentary system.
It
is the largest organ of the body
Composes ~15% of total body
weight in most individuals.
CLASSIFICATION OF BODY
MEMBRANES
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Mucous membranes
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line body cavities that open up to the outside, such as the digestive tract.
 The linings of the respiratory, reproductive, and urinary tracts are
examples of mucous membranes.
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Other examples: eyes, nose, mouth vagina, anus
Produce mucus, a thick secretion that keeps the membranes
soft and moist
Another purpose of mucus is to catch debris, and not allow it
to enter the body. It helps to keep out invading pathogens.
CLASSIFICATION OF BODY
MEMBRANES
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Serous Membranes
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Line the cavities that do not open to the outside world
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Examples include the heart, kidneys, spleen, and lungs.
Composed of two distinct layers of tissue
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Epithelial sheet is a thin layer of simple squamous epithelium
Connective tissue layer forms a thin, gluelike basement membrane
that holds and supports epithelial cells
In other words, serous membranes are double membranes.
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They may become inflamed due to infection.
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CLASSIFICATION OF BODY
MEMBRANES
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Double layered – the serous membrane is a single, continuous
sheet that covers two different surfaces
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Visceral membrane covers the surface of organs found in body cavities
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Parietal membrane lines body cavities
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A serous membrane that covers the organs found in a body cavity is referred to as
the visceral portion.
A serous membrane that lines the walls of a body cavity is referred to as the
parietal portion.
Serous fluid is in the cavity between them
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This fluid prevents friction when movement occurs
Friction would create a build-up of heat
Serous Membranes
Pleura = A serous membrane lining the walls of the thoracic cavity
and covering the lungs.
The parietal layer of the pleura adheres to the wall of the
chest and the visceral layer is attached to the lung. With
every breath we take the two layers slide past each other
with little friction, making it easier for us to breathe.
Peritoneum = serous membrane lining the walls of the abdominal
cavity and covering the organs in that cavity.
Synovial Membranes
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Synovial membranes are connective tissue
membranes
They do not contain epithelial components
 They line the spaces between bones and joints that move as
well as the lining of bursa sacs that are found
between many moving body parts
 Produce a lubricant called synovial fluid
 Synovial membranes and synovial fluid help to
reduce friction
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Disorders of Body Membranes
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Diseases
 Pleurisy—inflammation of the serous membranes that line
the chest cavity and cover the lungs
 Pain is caused by irritation and friction as the lungs rub
against the walls of the chest cavity
 Peritonitis—inflammation of the serous membranes in the
abdominal cavity that line the walls and cover the abdominal
organs
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A possible complication of appendicitis is inflammation of the serous
membrane that lines the abdominal cavity is and is termed peritonitis.
Integumentary System
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Integument = covering
The Integumentary system consists of:
Skin
 Accessory Organs:
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Hair
 Nails
 Glands
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The skin is the largest organ of the body
QUESTION:
What
are the functions
of the skin?
Functions of the Skin
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Protection from injuries
Acts as a barrier and regulates what
enters/leaves body.
Regulates body temperature.
Synthesizes and stores vitamin D
Sensory functions/sense organ activity
Temperature Regulation
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The skin helps with controlling our body
temperature by regulating sweat secretion and by
regulating the flow of blood close to the body
surface.
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Blood vessels to the skin constrict when the
body needs to conserve heat.
Functions of the Skin
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Sense organ activity
Skin functions as an enormous sense organ
 Receptors serve as receivers for the body, keeping it
informed of changes in its environment
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We have specialized receptors for light touch, pressure,
pain, heat and cold.
Functions of the Skin
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Protection—first line of defense
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Against infection by microbes
Against fluid loss
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Against ultraviolet rays from sun
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Keratin is a tough waterproof protein that gives the outer layer of
the skin some protection and helps to prevent dehydration.
Melanin is responsible for absorbing harmful ultraviolet radiation
from the sun before it reaches the deeper tissues of the
integumentary system.
Against harmful chemicals
Against cuts and tears
Structures of the Skin
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3 main layers from superficial to deep:
Epidermis
 Dermis
 Subcutaneous/
Hypodermis
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Structures of the Skin
1) Epidermis
Epiabove
derm/o
-is
skin
structure
“structure above the skin”
a. The outermost and primary layer of the skin.
b. The stratum corneum is the tough outer/superficial layer
of the epidermis. This layer contains keratin.
c. The innermost layer of the epidermis that that has cells
that continually reproduce with new cells moving toward
the surface stratum germinativum.
d. The epidermis is avascular.
Structures of the Skin
2) Dermis
Derm/o
-is
Skin
structure
“true skin”
a. thick, connective tissue layer with collagen and elastic
fibers, epithelial tissue, smooth muscle tissue, nervous
tissue and blood
b. The dermis lies directly above the subcutaneous
layer.
c. The dermis is thicker than the epidermis.
Dermis
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The dermal papilla forms ridges and grooves
that make up the fingerprints on the tips of the
fingers.
The purpose of skin ridges on our fingers and
toes is to improve our grip when using tools or
walking barefoot.
Loss of elasticity due to decreased numbers of
elastic fibers contributes to wrinkles and aging.
The dermis contains an abundance of elastic
fibers.
Subcutaneous injections of medicines are meant
to reach the hypodermis.
Sensory Structures of Dermis
Receptors of the integumentary system are
found in the dermis.
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Deep touch/pressure on the skin
surface/vibration: Pacinian corpuscles
Light touch/pressure: Meisner’s corpuscles
Warm temperature: Free nerve endings
Cold temperature: Free nerve endings
Pain: Free nerve endings
Structure of the Skin, cont.
3) Subcutaneous tissue/Hypodermis
Subcutane/o
-us
Below
skin
structure
“structure below the skin”
a. The hypodermis consists of adipose tissue which
provides insulation from extremes of heat and cold
as well as a source of stored energy. It can be used
as a food source in some situations. It also
provides a cushion of protection from injury.
You should be able to label this
diagram, found on p 103.
QUESTION:
What
are some of the
accessory structures of
the skin?
ANSWER:
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Hair
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Nails (produced by the epidermis)
Specialized Sense Organs (found in the dermis)
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Glands
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The skin itself is the main organ of the integumentary
system.
The integumentary system also INCLUDES the skin,
hair and specialized sense organs.
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Accessory Structures of the skin
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Hair
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The fine, soft hair of fetus and newborn called lanugo
Hair growth requires epidermal tube-like structure called hair
follicle (Fig 5.5, p 107)
Hair growth begins in the papilla when cells of the
epidermal layer grown down into the dermis, forming
a small tube called a hair follicle
Hair root lies hidden in follicle; visible part of the hair
is called the shaft
Alopecia is the term for hair loss
Arrector pili - specialized smooth muscle that
produces “goose bumps” and causes hair to stand up
straight when we become frightened or cold
Accessory Structures of the skin
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Nails (Figure 5-6, p 108)
Produced by epidermal cells over terminal ends of fingers
and toes
 Visible part called nail body
 Root lies in a groove and is hidden by
cuticle
 Crescent-shaped area nearest root called lunula
 Nail bed may change color with change in blood flow as it is
abundant in blood vessels
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Accessory Structures of the skin
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Skin glands
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Types
 Sweat or sudoriferous (apocrine and eccrine)
 Sebaceous
Accessory Structures of the skin
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Sweat or sudoriferous glands
 Types
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Eccrine sweat gland
 Most numerous, important, and widespread of the sweat glands.
There are more sweat glands than oil glands in one square inch of
skin.
 Produce perspiration or sweat, which flows out through pores on
skin surface. When this evaporates, the body loses heat.
 Function throughout life and assist in body heat regulation as
well as elimination of waste products such as ammonia and uric
acid
Accessory Structures of the skin
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Apocrine sweat gland
 Found primarily in axilla and around genitalia
 Secrete a thicker, milky secretion quite different
from eccrine perspiration
 Breakdown of secretion by skin bacteria produces
odor
 These glands enlarge and begin to function at
puberty
Accessory Structures of the skin
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Sebaceous gland
 Secrete oil/sebum to lubricate hair and skin
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Level of secretion increases during
adolescence
Amount of secretion regulated by sex hormones
 Sebum accunulation in sebaceous gland ducts
forms white pimples, and sebum often darkens
when exposed to air, forming a blackhead
 Acne vulgaris is the term for inflammation of
sebaceous gland ducts
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Dermis
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Sweat gland
Sebaceous gland
Arrector pili muscle
Blood vessels
The Skin
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Appendages of the skin
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Receptors
Receptors are specialized nerve endings that make it
possible for the skin to act as a sense organ
 Meissner’s corpuscle—capable of detecting
light touch; located close to the skin surface
 Pacinian corpuscle—capable of detecting
pressure
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Quick Quiz
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Ok, quick quiz. Which layer of the skin does
not have a blood supply?
ANSWER
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Correct! The epidermis doesn’t have a blood
supply. The epidermis and subcutaneous tissues
do have a blood supply.
Quick Quiz
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Which layer has the pigment cells?
ANSWER
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The epidermis again. Remember that it has
many layers. The pigment cells begin
development in the dermis and migrate to the
epidermis as they mature.
Quick Quiz
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What is that pigment called?
ANSWER
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Melanin! It is produced by the melanocytes.
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This pigment is called melanin and is responsible
for giving the skin some of its color.
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Dark skinned individuals can get melanoma despite
the fact that the dark skinned individuals have more
melanocytes than fair skinned individuals.
Quick Quiz
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Which layer has the fatty tissue?
ANSWER
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The subcutaneous tissue/hypodermis.
Burns
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The severity of a burn is determined by the depth of the injury as
well as by the amount of surface area involved.
 First-degree (partial-thickness) burns - only the surface layers of
epidermis involved. Causes minor discomfort and some skin
reddening, but no blistering and minimal damage. Example:
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typical sunburn.
Second-degree (partial-thickness) burns - involve the deep epidermal
layers and always cause injury to the upper layers of the dermis.
Causes blisters, reddening of the skin, severe pain, swelling and
fluid loss. Scarring is also common.
Third-degree (full-thickness) burns — characterized by complete
destruction of the epidermis and dermis and tissue death
extends into subcutaneous tissues. Often involve muscles and
bone. Not painful because nerve endings are destroyed.
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This is the most serious type of burn.
The most serious complications of third degree burns is fluid loss
and risk of infection.
Burns
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All of the following can cause burns to the
skin:
Electricity
 Ultraviolet light
 Chemicals
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Burns
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Determining the extent of burn injury is
possible by utilizing the “rule of nines” in
adults; this estimates the body surface area
effected by the burn.
The body is divided into 11 areas of 9% each
 Additional 1% of body surface area around genitals
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The Rule of Nines
**Be able to use the Rule of Nines to answer a
question regarding %age of body burned based on a
scenario provided on your exam**
Skin Cancer
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Three common types
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Squamous cell carcinoma—is common; lesions begin as hard,
painless nodules; it will metastasize.
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Metastasis is when cancer spreads to distant sites
from where it originated.
Basal cell carcinoma— the most common type of skin cancer.
 Melanoma— the most serious type of skin cancer. Is
indicated by a pigmented spot that contains different colors.
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Warning Signs of Malignancy
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The "ABCD" rule of self-examination of moles
refers to the warning signs of melanoma.
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Assymetry – benign moles are normally symmetrical, whereas malignancies
are not
Border – benign moles have a distinct border, whereas malignancies are
indistinct or irregular
Color – benign moles are brown and even colored whereas malignancies are
unevenly colored and often have a mix shades and colors
Diameter – malignancies tend to be larger than ¼ inch in diameter
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Skin Cancer
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The most important causative factor in common
skin cancers is exposure to sunlight.
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In other words, ultraviolet radiation is the most
important factor in causing skin cancer.
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UV radiation damages the DNA in skin cells which
interferes with normal mitosis and leads to cancer.
Decubitus Ulcers
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Decubitus ulcers (aka bedsores/pressure sores)
develop when excessive pressure slows down blood flow to
sensitive areas
 More common in bedridden or immobilized individuals
 However, they are NOT always a sign of abuse.
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Miscellaneous
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Cyanosis is when the skin or mucous
membranes turn blue because of too little
oxygen to the tissues.
Let’s
Review!
Which type of body membrane lines
the digestive tract?
A. Cutaneous membrane
B. Tympanic membrane
C. Serous membrane
D. Synovial membrane
E. Mucous membrane
ANSWER
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Answer: E
Mucous membrane lines cavities that are open
to the exterior, which includes the lumen of the
digestive tract.
The skin plays important roles in
maintaining a stable body
temperature.
A. True
B. False
ANSWER
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Answer: A
How? Via sweating and diversion of blood
flow.
What is the largest sensory organ of
the body?
A.Eye
B.Ear
C.Tongue
D.Skin
E.Nose
ANSWER
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Answer: D
All the sensory receptors in the largest organ of
the body make skin the clear winner.
What characterizes second-degree
burns?
 A.
blisters
 B. swelling
 C. severe pain
 D.all of the above
ANSWER
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Answer: D
That’s All, Folks!