Transcript 4 Integumentary & Membranes

Chapter 4
The Integumentary System and Body
Membranes
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Slide 0
Classifications of Body Membranes
• Classifications of body
membranes (F 4-1)
 Epithelial membranes—
composed of epithelial
tissues and an underlying
layer of connective tissue
 Connective tissue
membranes—composed
largely of various types
of connective tissue
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Slide 1
Classifications of Body Membranes
• Epithelial membranes
 Cutaneous membrane—the skin
 Serous membrane—simple squamous
epithelium on a connective tissue basement
membrane

Types
o
o
Parietal—lines walls of body cavities
Visceral—covers organs found in body cavities
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Slide 2
Classifications of Body Membranes

Examples
o
o

Pleura—parietal and visceral layers line walls of the
thoracic cavity and cover the lungs
Peritoneum—parietal and visceral layers line the
walls of the abdominal cavity and cover the organs
in that cavity
Diseases
o
o
Pleurisy—inflammation of the serous membranes
that line the chest cavity and cover the lungs
Peritonitis—inflammation of the serous membranes
that line the walls of the abdominal cavity and cover
the abdominal organs
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Slide 3
Classifications of Body Membranes
 Mucous membranes
Line body surfaces that open directly to the
exterior
 Produce mucus, a thick secretion that keeps the
membranes soft and moist

(Cont’d…)
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Slide 4
Classifications of Body Membranes
• Connective tissue membranes
 Do not contain epithelial components
 Produce a lubricant called synovial fluid
 Examples are the synovial membranes in the
spaces between joints and in the lining of bursal
sacs
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Slide 5
The Skin (F 4-2)
• Structure—two primary layers called epidermis
and dermis
 Epidermis
Outermost and thinnest primary layer of skin
 Composed of several layers of stratified squamous
epithelium
 Stratum germinativum—innermost layer of cells
that continually reproduce, and new cells move
toward the surface

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Slide 6
The Skin
As cells approach the surface, they are filled with
a tough waterproof protein called keratin and
eventually flake off
 Stratum corneum—outermost layer of keratinfilled cells
 Pigment-containing layer—epidermal layer that
contains pigment cells called melanocytes, which
produce the brown pigment melanin
 Blisters—caused by breakdown of union between
cells or primary layers of skin
 Dermal—epidermal junction—specialized area
between two primary skin layers

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Slide 7
The Skin
 Dermis
Deeper and thicker of the two primary skin layers
and composed largely of connective tissue
 Upper area of dermis characterized by parallel
rows of peglike dermal papillae
 Ridges and grooves in dermis form pattern unique
to each individual

o
o
Basis of fingerprinting
Improves grip for tool use and walking
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Slide 8
The Skin
Deeper areas of dermis filled with network of
tough collagenous and stretchable elastic fibers
 Number of elastic fibers decreases with age and
contributes to wrinkle formation
 Dermis also contains nerve endings, muscle
fibers, hair follicles, sweat and sebaceous glands,
and many blood vessels

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Slide 9
(F 4-2)
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Slide 10
The Skin
• Appendages of the skin
 Hair (F 4-4)
Soft hair of fetus and newborn is
called lanugo
 Hair growth requires epidermal
tubelike structure called hair
follicle
 Hair growth begins from hair
papillae
 Hair foot lies hidden in follicle and
visible part of hair called shaft
 Arrector pili—specialized smooth
muscle that produces
“goosebumps” and causes hair to
stand straight up

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Slide 11
The Skin
 Receptors (F 4-6)
Specialized nerve endings—make it possible for
skin to act as a sense organ
 Meissner’s corpuscle—capable of detecting light
touch
 Pacinian corpuscle—capable of detecting pressure

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Slide 12
The Skin
 Nails (F 4-7)
Produced by epidermal
cells over terminal
ends of fingers and
toes
 Visible part is called
nail body
 Root lies in a groove
and is hidden by cuticle
 Crescent-shaped area
nearest root is called
lunula
 Nail bed may change
color with change in
blood flow

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Slide 13
The Skin
 Skin glands

Types
o
o
Sweat or sudoriferous
Sebaceous
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Slide 14
The Skin

Sweat or sebaceous glands
o
Types
•
•
•
•
Eccrine sweat glands
Most numerous, important, and widespread of the
sweat glands
Produce perspiration or sweat, which flows out
through pores on skin surface
Function throughout life and assist in body heat
regulation
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Slide 15
The Skin
•



Apocrine sweat glands
Found primarily in axilla and around genitalia
Secrete a thicker secretion quite different from eccrine
perspiration
Breakdown of secretion by skin bacteria produces odor
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Slide 16
The Skin

Sebaceous glands
o
o
o
o
Secrete oil or sebum for hair and skin
Level of secretion increases during adolescence
Amount of secretion is regulated by sex hormones
Sebum in sebaceous gland ducts may darken to
form a blackhead
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Slide 17
The Skin
• Functions of the skin
 Protection—first line of defense:
Against
 Against
 Against
 Against

infection by microbes
ultraviolet rays from the sun
harmful chemicals
cuts and tears
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Slide 18
The Skin
 Temperature
regulation

Skin can release
almost 3000
calories of body
heat per day
o
Mechanisms of
temperature
regulation
Regulation of sweat
secretion
• Regulation of flow
of blood close to
the body surface
•
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Slide 19
The Skin
 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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Slide 20
The Skin
• Burns (F 4-8)
 Treatment and
recovery or survival
depend on total area
involved and severity
or depth of burn
 Body surface area is
estimated using the
“rule of nines” in
adults

Body is divided into
11 areas of 9% each
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Slide 21
The Skin
 Classification of burns
First-degree (partialthickness) burns—only
the surface layers of
epidermis involved
 Second-degree (partialthickness) burns—
involve the deep
epidermal layers and
always cause injury to
the upper layers of the
dermis

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Slide 22
The Skin

Third-degree (full-thickness) burns—characterized
by complete destruction of the epidermis and
dermis
o
o
o
May involve underlying muscle and bone
Lesion is insensitive to pain because of destruction
of nerve endings immediately after injury—intense
pain is soon experienced
Risk of infection is increased
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Slide 23
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Slide 24